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CONTENTS

Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7Presentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13Goals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15Committee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

OVERVIEW/PLENARy LECTURES ON ThE ROLE OF SUPERCRITICAL FLUIDS AND TEChNOLOGy (SCFs&T)

State of SCFs&T — Future Directions and Progress in Commercialization . . . . . . . . . . 19

SCFs&T for Bio-based Fuel processes . . . . . . . . . . . 39

SCFs&T for New Materials and Materials Processing . . . . . . . . . . . . . . . . . . 49

SCFs&T for Green Chemistry and Sustainable Technology . . . . . . . . . . . . . . . 69

SCFs as Working Fluids and Process Technology . . . 83

PANEL PRESENTATIONSPanel I: Bio-based fuel processes . . . . . . . . . . . . . . 103

Panel II: New Materials and Materials Processing . . . . . . . . . . . . . . . . . 129

Panel III: Green Chemistry and Sustainable Technology . . . . . . . . . . . . . . 159

Panel IV: SCFs as Working Fluids / Process Technology and Design . . . . . . . . . . . . . . . . . . 187

Panel V: Process Technology and Future Direction . . . . . . . . . . . . . . . . . . . . 215

POSTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243

Index. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 387

7

PREFACE

It is with pleasure that we present this book of abstracts

of the lectures and posters that will be presented at the

Workshop on Supercritical Fluids and Energy.

The idea of organizing a workshop on supercritical

fluids with a focus on energy emerged during the course

of casual exchanges between the co-directors of this work-

shop who shared the same dinner table at the Gala Dinner

at the 10th International Symposium on Supercritical Flu-

ids held in San Francisco in May 2012. The discussions

had initially started with commentaries on the ongoing

symposium and on the current status and future directions

of the supercritical fluid science and technology. One of

the questions that immediately surfaced was “how come

no industrial plants that employ supercritical fluids had

been built in Brazil or in South America despite decades

of ongoing active research by many in the region?” The

discussion quickly expanded and the questions became

broader. Brazil having played such an important role in

bio-ethanol production, and there being an ever increasing

interest in alternative fuels around the world, we ques-

tioned how new opportunities could be developed for the

supercritical fluid-based technologies to make an impact

in Brazil and elsewhere. What were the limitations? Where

were the bottlenecks? What was missing on fundamental

data? Were there misconceptions, if any, that needed to

be overcome to raise the level of interest for industrial

implementation? Were there a critical mass of trained en-

8 SFE 2013 | WORKShOP ON SUPERCRITICAL FLUIDS AND ENERGy

gineers who could take charge of such facilities and run

them safely if they were to be built? Furthermore, since

supercritical fluid research could impact “energy” use or

savings in many other ways than just developing new ap-

proaches to generate alternative fuels, additional questions

were raised on the impact of using supercritical fluids as

working fluids in power cycles; the energy saving potential

in materials processing, or forming new materials ranging

from particles, to fibers, to foams and aerogels with super-

critical fluids. It immediately became clear that addressing

these questions would greatly benefit our greater commu-

nity.

When viewed under such a broad umbrella, the ap-

peal of a Workshop, rather than a traditional conference

or symposia became extremely high as it would then be

attractive to colleagues with different backgrounds; with

everyone easily contributing by sharing their perspectives

of what is known, what is needed, and where the future

trends in the field lie from their own strength areas, while

gaining new perspectives in others. With this background,

we started to seek funding for the Workshop. The goal was

to generate sufficient funds to facilitate participation not

only by experts but also by young scientists. The Journal

of Supercritical Fluids made an early commitment to sup-

port the idea as the timing of the workshop would nicely

coincide with and mark the 25th anniversary of the Journal

being in publication. LASEFI was also immediately on

board. One of us (E. Kiran) discussed the idea with the

program managers for “Environmental Sustainability” and

“Energy and Sustainability” at the National Science Foun-

dation at the 2012 AIChE Annual Meeting in Pittsburg in

November 2012, and then submitted a proposal to NSF

which was funded. Simultaneously, a similar project was

submitted (by M.A.A. Meireles) to CNPq (Conselho Nacio-

PREFACE 9

nal de Desenvolvimento Científico e Tecnológico/ Nation-

al Council for Scientific and Technological Development)

in Brazil which was also funded.

With a sound base-funding secured from NSF,

LASEFI, CNPq and the Journal of Supercritical Fluids, the

workshop was formally announced at the 3rd Iberoamer-

ican Conference on Supercritical Fluids that was held in

Cartagena, Colombia in April 2013.

Our initial plans were to organize a modest work-

shop with a total of about 50-60 participants consisting of

25-30 experts and 25-35 postdoctoral fellows or senior grad-

uate students. However, the interest in the workshop far

exceeded our initial expectations. We are extremely pleased

that we have a total of 104 participants from 20 different

countries.

The first day of the technical sessions of the work-

shop is devoted to a total of 21 overview/plenary lectures

that are grouped under

1. State of the supercritical fluid science and technol-

ogy — future direction and status of commercial-

ization,

2. Supercritical fluid science and technology for bio-

based fuel processes,

3. Supercritical fluid science and technology for new

materials and materials processing,

4. Supercritical fluid science and technology for green

chemistry and sustainable technology and

5. Supercritical fluids as working fluids and process

technology.

The second day of technical sessions is devoted to

37 lectures on the role of supercritical fluid science and


technology that will be presented and discussed in five

parallel-run Panel sessions grouped under:

1. Bio-base fuel processes

2. New materials and materials processing

3. Green chemistry and sustainable technology

4. Supercritical fluids as working fluids / process tech-

nology and design

5. Process technology and future directions.

Also scheduled for the second day of the workshop

is the afternoon Poster Session that will have 42 presen-

tations by junior faculty members, postdoctoral fellows,

research associates, or senior graduate students.

The third day of the workshop is devoted to the

presentations and the discussions of the panel outcomes

by all participants.

This book of abstracts includes all the abstracts of

the overview and the panel lectures and the poster pre-

sentations which we trust you will find of value as a future

reference.

We would like to take this opportunity to thank all

the participants for their willingness to come to this work-

shop and share their knowledge, and their commitment

to the advancement of our field. We are optimistic that

this workshop will lead to new interactions and collabo-

rations, and in particular will help the next generation of

scientists to be connected with our greater community.

We are grateful to our international and local organizing

committee members, Drs. Gerd Brunner, Richard Smith,

Flávio C. Albuquerque, Sandra R. S. Ferreira, Camila G.

Pereira, Hosiberto B. Sant’Ana and Diego T. Santos for their

valuable insight in organization and help with the logistics.

PREFACE 11

We would also like to thank the various government

and private organizations which have provided additional

financial support to make this workshop possible. Our spe-

cial thanks go to Drs. Bruce Hamilton and Ram Gupta of

the National Science Foundation, CNPq, CAPES-PROEX,

Dr. Angela Welch of Elsevier and the Journal of Supercrit-

ical Fluids, Dr. J. W. King of the Supercritical Fluid Sym-

posia, Dr. Jacques Fages of the International Society for

Advancement of Supercritical Fluids, Volkmar Steinhagen

of UHDE, Chris Spilsbury of the BG Group, and Kenneth

R. Krewson of Supercritical Fluid Technologies.

M. Angela A. MeirelesErdogan Kiran

Workshop Directors

13

PRESENTATION

Supercritical fluids are a unique class of process fluids

and solvents, which display tunable properties. They are

employed at conditions beyond the thermodynamic vapor-

liquid critical point. At those conditions, properties of su-

percritical fluids can be changed over a wide range, and

adapted to process needs. They are attractive process fluids

in combining a set of unique properties like low viscosity,

high diffusivity, zero surface tension, and a high compress-

ibility. Water, for example, is used extensively as working

fluid in power generation processes, at conditions below

the critical point and increasingly at supercritical condi-

tions. Carbon dioxide and ammonia are utilized in a similar

way.

Supercritical fluids modify the properties of com-

pounds in mixtures. They dissolve components far beyond

their vapor pressure. They dissolve in other fluids and solids,

reducing their viscosity and surface tension substantially.

In chemical reactions, supercritical fluids act as non- reac-

tive process fluid or take part in the reaction, as is the case

with water in hydrolysis of biomass components or in ox-

idative waste destruction. In materials processing, super-

critical fluids become effective in modulating miscibility

and phase separation conditions leading to formation of

materials with a range of different morphologies.

The practical application of supercritical fluids re-

quires understanding of the fundamentals of multiphase

equilibria at high pressures and ultimately the design of


technical components and plants for production. Compared

to other technical systems, supercritical fluid production

plants are relatively simple, but the underlying principles

are complex and must be thoroughly investigated and

transferred to the users.

Significant advances have been made over the past

three decades in understanding the interaction of super-

critical fluids with natural and synthetic materials for phys-

ical and chemical transformations with beneficial results

that offer new and alternative pathways to materials pro-

cessing. Advances have also been made in the engineering

of processes, which employ supercritical fluids as process

media. One area of special importance that has emerged

is “Energy” in terms of the (a) use of supercritical fluids

in power generation or refrigeration; (b) use of supercriti-

cal fluids in biomass conversions for biofuel generations;

(c) use of supercritical fluids in reducing the environmen-

tal footprint of conventional processes; (d) use of supercrit-

ical fluids in generating new materials that have improved

thermal insulation properties; or (e) use of supercritical

fluids or supercritical-fluid based materials in improved

separation or property upgrading operations.

A current bottleneck is in overcoming some of the

misconceptions pertaining to overall costs and economics

of the potential processes in transforming the technology

base to large-scale implantations. It is with this background

that the proposed workshop is being organized.

The workshop will be held in Brazil, which is lead-

ing in its activity in bio-based alternative fuels and as such

is a natural location to address the central topic of Energy.

Brazil is also a location where intense activity is taking

place in bio-based material processing and will provide a

platform to look at the limitations in going from bench top

research to industrial implementation.

15

GOALS

The primary objective of this workshop is to create an

opportunity to (a) critically review the state of supercritical

fluid science and technology and its impact in various

facets of energy generation or energy savings and reveal

new perspectives for the improvement of energy related

processes, (b) assess the bottlenecks that are preventing

industrial scale implementation, (c) develop recommenda-

tions to facilitate transformation of lab scale findings to

large scale operations, and in so doing (d) identify future

research needs and mechanisms to rejuvenate and strength-

en interest and continuing support from federal agencies

for fundamental research to promote further developments.

The SFE’13 also intends to engage up and coming

new leaders in supercritical fluid science and technology

by bringing them to this workshop, and having them ful-

ly integrated into the broader network and give them a

stronger base to move forward. In 1993 and 1998 two NATO

Advanced Study Institutes had been organized each of

which had brought together about 25 lecturers and 75

young scientists. Those young scientists have themselves

now become leading names around the world with very

effective networking. It is anticipated that this workshop

will have a similar impact. Even though smaller in scale,

the workshop will be addressing an extremely significant

focus area and we believe will have a major impact.

We anticipate that the workshop will form a nucleus

for new collaborative efforts and possible multi-national

research initiatives.

17

COMMITTEE

WORKShOP DIRECTORS

M. Angela A. Meireles, University of Campinas, Brazil – Founder of Laboratory of Supercritical Technology: Extraction, Fractionation, and Identifi cation of vegetable extracts (LASEFI); [email protected]

Erdogan Kiran, Virginia Polytechnic Institute and State University, USA

– Founder and Editor-in-Chief of the Journal of Supercritical Fluids; [email protected]

INTERNATIONAL SCIENTIFIC COMMITTEE

Gerd Brunner, Hamburg University of Technology, Germany – Regional Editor (Europe) of the Journal of Supercritical Fluids

M. Angela A. Meireles, University of Campinas, Brazil

Erdogan Kiran, Virginia Polytechnic Institute and State University, USA

Richard Smith Jr., Tohoku University, Japan – Regional Editor (Asia) of the Journal of Supercritical Fluids

LOCAL ORGANIzING COMMITTEE

Flávio C. Albuquerque, PETROBRAS Research & Development Center,

Brazil

Sandra R. S. Ferreira, Federal University of Santa Catarina, Brazil

Camila G. Pereira, Federal University of Rio Grande do Norte, Brazil

Hosiberto B. Sant’Ana, Federal University of Ceara, Brazil

Diego T. Santos, University of Campinas, Brazil


State of SCFs&T — Future Directions and Progress in Commercialization

PROCESS TEChNOLOGy AND FUTURE DIRECTIONS

21

PROCESS TEChNOLOGy AND FUTURE DIRECTIONS

gerd BrunnerHamburg University of Technology;

Eissendorfer Str. 38, D-21073, Hamburg, Germany; E-mail: [email protected]

what is “Process Technology”?

Process technology comprises the application of

fundamentals to processes, as for example phase equilib-

ria and reaction kinetics, the verification of process steps,

as for example in specific reactors, and the design of pro-

cess sequences to produce a product (energy!) from raw

materials.

For the special field of Supercritical Fluids related

to energy processes this general definition also applies.

Self-evident as this is, it includes single process steps as

well as process step sequences and whole processes. Also,

process technology is not restricted to any specific appli-

cation. It includes processing of renewable (bio-based)

materials, fossil materials, and processes to access these

materials.

In general, process technology related to the appli-

cation of supercritical fluids is based on the exploitation

of the specific properties of supercritical fluids. Again,

self-evident as it is, it includes the varying properties of

supercritical fluids itself and hence the tunability of the

working fluid and the interactions of supercritical fluids

with the processes materials. Mostly we have in mind in

this context the change of properties by dissolved super-

critical fluids, for example a drastically reduced viscosity.


Furthermore, supercritical fluids guarantee an enclosed

processing with emanations that can be adjusted. Super-

critical fluid processing of most materials results in a re-

duced amount of gas production. That gas can still be used

to fuel the process. In addition, supercritical fluids can

lead to improved yields, as I will show in an example for

oil shale exploitation, and in improved quality of the prod-

ucts.

Supercritical fluids have been used in quite a num-

ber of processes and process steps related to production

of energy, mostly in laboratory and demonstration scale.

Among these processes are: The ROSE process, coal liq-

uefaction and gasification, the production of oil from oil

shales, and of oil from oil sands.

Supercritical fluids have been proposed (and par-

tially are used) for: enhanced oil recovery, emulsion split-

ting (oil-water), enhanced gas recovery, bitumen separation,

recovery of hydrocarbons from particles (remediation of

soil), de-asphalting, removal of fine particles, and others.

Supercritical fluids are proposed for deep drilling (spall-

ation drilling), and for the production of energy from hy-

drothermal flames.

Process technology has to provide the equipment

for the processes. In general, there is no principal differ-

ence for bio-based materials and non-bio-based materials.

Design according to the process fundamentals has to be

provided for: reactors, heat transfer equipment, heat re-

covery systems, and systems for delivery and recovery of

solids. In addition, the question of corrosion has to be an-

swered.

Future directions can be seen in the provision of

fundamentals: for oil/water/SCF-processes, for oil/water/

SCF/particles-processes, for the design of small scale in-

stallations (economy, standardization), and for the design

STATE OF SCFs&T | FUTURE DIRECTIONS AND PROGRESS IN COMMERCIALIzATION 23

of proper technology for feeding and removal of solids.

Keys to future success will be: simple design, simple op-

eration, high efficiency (higher than burning the feed),

and a thorough training of the community in the specific

abilities of supercritical fluids.

ChALLENGES AND OPPORTUNITIES USING SUPERCRITICAL CO2: FROM FUNDAMENTALS TO INDUSTRIAL APPLICATIONS

25

ChALLENGES AND OPPORTUNITIES USING SUPERCRITICAL CO2: FROM FUNDAMENTALS TO INDUSTRIAL APPLICATIONS

Lourdes f. vegaMATGAS Research Center / AIr Products Group;

MATGAS Building – Campus UAB, 08193, Bellaterra, Barcelona, Spain; E-mail: [email protected]

As defined by the Brundtland Commission, sustainable

development is the development that “meets the needs of

the present without compromising the ability of future

generations to meet their own needs”. Sustainable devel-

opment is of special relevance in the present situation, in

which an explosive growth in energy consumption as a

consequence of the great inventions and developments

related to transportation, computers and technology is

observed, along with a rapid increase in population world-

wide. In this context, a great effort has been devoted in

recent years to develop sustainable processes or improving

existing ones, searching for a net positive impact in the

environment.

Carbon dioxide (CO2) is finding more and more uses

in industry today, from food and water treatment to ener-

gy and materials, replacing in some cases other com-

pounds with more impact into the environment. Among

these applications, supercritical carbon dioxide (scCO2) is

used as an alternative attractive solvent, replacing tradi-

tional ones, including hazardous chemicals and precious

water resources. scCO2 offers several advantages versus

other solvents: it can be easily recycled, it leaves no resi-

dues behind after processing and it is non-flammable,

non-toxic and inexpensive. The low process temperature


(31 ºC) allows for gentle processing, while the low surface

tension of scCO2 and its high diffusivity allows for excep-

tionally effective penetration. Increased environmental

awareness had led to restrictions on some traditional sol-

vents which are now recognized as toxic. Only a few sus-

tainable solvents remain available for future use. Hence,

as the society and industry continue to demand more ef-

ficient and greener processes, CO2 remains an attractive

alternative.

There are three key issues driving CO2 applications

from labs to industry: the increased fundamental knowl-

edge of CO2 and its interaction with the materials and

other compounds, used to find the best process and oper-

ating conditions, the optimization of process equipment

to handle the demands of operation at an industrial scale,

and the need to use environmentally benign solvents and

greener processes. In this context, and thanks to the suc-

cess of adequate modeling tools, accurate experimental

measurements and the optimization of the equipments at

industrial scale, the use of scCO2 has transitioned, over the

past twenty-five years, from a laboratory-based research

to a commercial reality, with applications in high-value

products such as in pharmaceuticals, nutraceuticals, foods

and flavors, polymers and chemicals, as well as in bulk

commodity products such as textiles, biofuels and cement.

After a general overview, we will address some of

the recent applications of CO2 in which our team has been

involved, including the recovery of solutes from ionic liquids

with CO2 or separation of ionic liquids from organic sol-

vents by CO2 [1,2], the preparation of organic-inorganic

materials by scCO2 for CO

2 capture and other applications

[3-5], the use of scCO2 to extract high added value products

and the scCO2 role in the biofuel arena. Modeling and ad-

vanced experimental techniques, from small reactors to


pilot plants have been used in order to move the technol-

ogy forward.

This work is part of a CENIT project SOST-CO2 be-

longing to the Ingenio 2010 program financed by CDTI,

Science and Innovation Department, Spanish Government,

aiming at reducing the emissions of CO2 in Spain and de-

veloping new industrial and sustainable uses of CO2. The

project is lead by the company Carburos Metálicos, from

Air Products Group, and it comprises 14 other companies

and 31 research institutions. Support for this work from

Air Products and the Spanish Government through project

CEN-2008-1027 (CENIT SOST-CO2) is gratefully acknowl-

edged. Additional support was provided by the Spanish

Government (CTQ2008-05370/PPQ, CTQ2011-23255) and

by the Catalan Government (2009SGR-666).

The work presented here has been done in collab-

oration with F. Llovell, S. Builes, O. Vilaseca, R.M. Marcos,

R. Solanas, J. Torres, P. López-Aranguren and C. Domingo.

Their contributions and continuous support is very much

appreciated.

REFERENCES

[1] F. Llovell, O. Vilaseca, L. F. Vega, Thermodynamic modeling of imidaz-olium-based Ionic Liquids with the [PF6] anion by means of the soft-SAFT EoS, Separation Science & Technology, 47 (2011) 399-410.

[2] F. Llovell, E. Valente, O. Vilaseca, L. F. Vega, Modeling complex asso-ciating mixtures with [Cn-mim][Tf2N] ionic liquids: predictions from the soft-SAFT equation, J. Physical Chemistry B., 115 (2011) 4387-4398.

[3] P. López-Aranguren, J. Saurina, L. F. Vega, C. Domingo, Sorption of try-alkoxysilane in low-cost porous silicates using a supercritical CO2 meth-od, Microporous and Mesoporous Materials, 148 (2012) 15-24.

[4] S. Builes, L. F. Vega, Effect of Immobilized Amines on the Sorption Properties of Solid Materials: Impregnation versus Grafting, Langmuir, 9 (2013) 199-206.

[5] S. Builes, P. López-Aranguren, J. Fraile, L. F. Vega, C. Domingo, Alkylsilane- Functionalized Microporous and Mesoporous Materials: Molecular Simulation and Experimental Analysis of Gas Adsorption, J. Physical Chemistry C, 116 (2012) 10150-10161.

COMMERCIALIzATION OF SUPERCRITICAL FLUID PROCESSES AND PRODUCTS — A PERSPECTIVE

29

COMMERCIALIzATION OF SUPERCRITICAL FLUID PROCESSES AND PRODUCTS — A PERSPECTIVE

Jerry W. King CFS – University of Arkansas;

1965 E. Spinel Link #7; 72701, Fayetteville, AR, USA; E-mail: [email protected]

Commercializing processes and products that involve pres-

surized fluids technology has been on-going for over four

decades. This presentation is focused on the current sta-

tus of processes and products contrasted with and future

trends/needs as well as application areas. The success of

applying a pressurized or supercritical fluid for processing

lies in producing a product derived by either extraction-frac-

tionation-reaction methods that is cost competitive with

existing products, or fulfills a need where the end user is

willing to pay a premium for the benefits derived from the

“supercritical” product. This can be challenge in emerging

economies such as representing by the BRIC (Brazil-Russia -

-India-China) countries as typified by consumer attitudes

toward particular products, such as EPA and omega-3 fat-

ty acid nutraceutical supplements.

It is interesting to examine platforms, not only in

terms of integration of pressurized processing options in-

cluding critical fluids, but also where the energy versus

higher value product use of a renewable substrate perhaps

are in competition with one another. For example, consid-

er the case of oils used for either renewable biodiesel ver-

sus processing them with scCO2 to extract higher-value

nutraceutical ingredients. This competition is particular-

ly acute when the renewable oil source is from algae where


the oil can be converted to biodiesel via several routes

which can use supercritical media (scCO2, supercritical

methanol, etc.), or be processed using scCO2 for its omega

fatty acid content (market potential: 2011 — $25.4 billion;

2016 — $34.7 billion — 6.4% rate increase compounded

annually), or antioxidant content such as astaxanthin

(~$10,000/kg). Several case examples will be provided

where a common feed stock such as algae can be frac-

tionated to produce a multiple product portfolio having

diversified economic benefit.

Today SFE is driven by the scCO2 processing of nu-

traceutical/functional food ingredients. Newer SFE “ultra-

high” pressure processing plants are now operational and

employ extraction pressures up to and beyond 1000 bar.

Such conditions permit the co-extraction of synergistic

components, i.e., both non-polar and polar compounds

which can be rationalized based on their solubility param-

eters relative to that exhibited by scCO2 at higher pressures

and temperatures. It is more difficult to discern commer-

cial products realized by using columnar fractionation or

SFC that are being produced on a commercial scale de-

spite considerable research in these areas. Likewise prom-

ising reaction chemistries conducted in the presence of

supercritical fluids, such as enzyme-based conversions,

hydrogenation, etc. have yet to produce commercially-vi-

able products.

The use of pressurized water, both in its sub- and

super-critical fluid state has been undertaken now for over

three decades. The use of pressurized water ranges over

a considerable temperature range augmented by appro-

priate pressures based on its phase diagram. These range

from very low pressure conditions for subcritical water

extraction (SWE) to higher pressures/temperatures applied

in treating renewable energy feed stocks for both chemical


and fuel utilization. SWE has received much attention due

to the many studies conducted on agriculturally-based

renewable materials, and the promise that it can replace

organic solvent-based processes — hydroethanolic extrac-

tion. The future development of this processing technique

is very dependent, as most of the high temperature bio-

mass processing technologies on the development of a

continuous solids feeding system compatible of operating

at higher temperatures and variable pressures. Our stud-

ies at the University of Arkansas with modified expeller

or auger delivery systems have shown modest success

when applied for processing anti-oxidant botanical ex-

tracts. The compatibility and cost of such systems can be

reduced by applying conventional 316 SS alloys up to the

critical point of water, beyond which biomass reforming,

pyrolysis, and gasification require more expensive equip-

ment.

Perhaps the ultimate criterion of the worth of R &

D using high pressure fluids is whether a long term com-

mercial product is realized as the end goal. Examples of

successful product platforms have been reviewed by au-

thor in the past — the question is what does the future

hold? As noted above, developments in SFE are driven by

high-value extracts containing ingredients that can pro-

vide flavor, antioxidant, or desirable physical properties

due to their multi-component composition. Examples of

such extracts occur from applying SFE to algae and certain

marine-derived products such as krill oil, where the syn-

ergistic benefit of extracts containing omega-fatty acids,

naturally-derived pigments, and phospholipids have been

verified in clinical studies. The extension of these extracts

as medicines will require that SFE and related processes

be conducted under GMP (Good Manufacturing Practice)

conditions, which is different from the criteria applicable


under GLP and GRAS regulations. To date in the develop-

ment of SCF-based processes, GMP conditions are not

always adhered to, but some GMP protocols have been

recorded in the preparing particles for the pharmaceutical

industry using various pressurized fluids, and similarly in

the use of SFC. Despite industrial interest in sub-critical

water extracts, such products are difficult to verify in the

marketplace. The promise of chemicals and extractives

produced by high pressure aqueous processing has often

been reported, but downstream purification of these com-

plex extracts and the separation of these components from

aqueous media remains a problem due to the additional

unit processing costs. In addition, sometimes conversion

of these extracted solutes by reaction chemistry is required.

Two examples relevant to the above problems will be cit-

ed — the extraction of natural polyphenolic antioxidants

using SWE or CO2-based extraction, and obtaining the

cosmetic ingredient, squalane, from sugar cane biomass.

Such extracts are now finding an increased use in the per-

sonal care industry and pertinent products will be shown.

The consumer is becoming increasingly aware of what

differentiates a supercritical fluid-derived product from

those obtained via conventional or alternative routes. Ex-

amples will be shown of “embracing” the supercritical

fluid logo in product advertising as well as benefits that

accrue from using a supercritical fluid process, such as

the problem with solvent residuals in products. The latter

problem beckons for a “supercritical fluid solution”, due

to more stringent legislation that is being applied on prod-

ucts intended for health food industry, cosmetic applica-

tions, and for medical use. Such products include both

extracts and raffinates — saleable products left over after

critical fluid processing. Several examples of the latter

will be noted from the oilseed medicinal area and marine/


algal-derived products. While economic analysis of produc-

tion costs in the case of supercritical fluid-based process-

ing is important, it is not the only factor which determines

the success of commercial product. Derived products/pro-

cesses which appeal to the altruistic sensibilities of the

end consumer make critical fluid-based processing attrac-

tive. The utilization of “green” processing when coupled

with a bio-renewable/sustainable production platform can

be used advantageously in the marketing of end products

— particularly when they involve the utilization of CO2.

Many model or hypothetical bio-refineries with integrated

processing utilizing critical fluids have been envisioned,

but to date only discrete unit processes have been studied

in detail. Adoption of supercritical fluid-based technolo-

gies commercially can be greatly aided by utilizing “mo-

bile” plants that allow demonstration of the merits of the

technology within existing production facilities.

35

SUPERCRITICAL FLUIDS IN ENERGy AND BIOFUEL APPLICATIONS

Richard L. smith Jr.Tohoku University;

Aoba-ku, Aramaki Aza Aoba 6-6-11, Sendai, Miyagi-ken, 980-8579, Japan;

E-mail: [email protected]

Supercritical fluids have application in energy and biofu-

el processes in their use as (a) working fluids, (b) reaction

solvents, (c) mass transfer promoters, (d) heat transfer pro-

moters and (e) separation agents. This work introduces

applications of supercritical fluids that demonstrate some

of their unique technological advantages and presents

aspects of a proposal that uses supercritical CO2 with hy-

drogen and ionic liquids for the conversion of biomass to

biofuels. Supercritical fluids are being used as working

fluids in next-generation systems for refrigeration [1],

hot-water heating [2], heat-pump [3], natural gas [4-6],

geothermal [7], ultrasupercritical boiler [8] applications.

In these applications, the homogeneous phase conditions

of the transcritical state change gives highly-efficient en-

ergy transport. Supercritical fluids can be used as reaction

solvents in next-generation chemical processes for pro-

ducing biodiesel fuel from oilseed crops [9-14]. There are

a number of proposals for using supercritical fluids such

as methanol [12], combinations with acetic acid [14], meth-

yl acetate [13], and dimethylcarbonate [10], each with its

distinctive advance according to the use of raw materials

and chemical products and by-products. Use of supercrit-

ical methyl acetate as reaction solvent for triglycerides


gives triacetin and avoids the formation of glycerol [9].

Use of supercritical dimethyl carbonate gives glycerol car-

bonate as a value-added by-product [10]. In this strategy,

the solvent is a supercritical fluid that acts not only as a

solvent but also as a reactant and promotes heat and mass

transfer. In hydrothermal methods, water, which is some-

times combined with additives, is used to pretreat or con-

vert biomass into feedstocks suitable for biofuel production

[15-18]. In this strategy, the self-ionization of water is ex-

ploited to promote hydrolytic reactions and cellulose de-

polymerization. Ionic liquids, which are organic salts that

are commonly liquid at room temperature, offer an inter-

esting possibility to transform biomass into biofuels [19].

The ionic liquid can act not only as a solvent for biomass,

but also as a homogeneous catalyst for transforming bio-

mass substrates into biofuels [19]. In this strategy, an

ionic liquid is used as solvent for biomass, cellulose, or a

carbohydrate substrate. Many approaches have been tak-

en in the literature. In Qi et al. [20], cellulose is converted

into 5-hydroxymethylfurfural in high yields via a two-step

process that involves water addition to the reacting mix-

ture. In these systems, as biomass or its related constit-

uents are dissolved into an ionic liquid, the viscosity of

the solution greatly increases thus causing the mass trans-

fer to become greatly limited. When the viscosity is re-

duced by addition of organic solvents or a soluble gas,

such as supercritical CO2, many reactions can proceed

smoothly [21].

A proposal that we are examining in this work is

the transformation of biomass into fuels via catalytic meth-

ods [22]. In Chen et al. [22], sugars and polyols undergo

direct conversion into n-hexane and n-pentane via catalyst

in a triphasic (water-n-dodecane-hydrogen) system. For

glucose the reaction is:


C6H

12O

6 + 7H

2 -> C

6H

14 + 6 H

2O (1)

Although the method and catalyst give outstanding

results (99.9% conversion, 94+% yield), long reaction times

(84 h) are required due to mass transfer limitations of both

reactants and products. In this work, we consider the use

of supercritical CO2 in the objective for improving the re-

action efficiency of Eq. (1) and the use of ionic liquids to

expand the application of the catalytic system.

REFERENCES

[1] Y. T. Ge, S. A. Tassou, I. N. Suamir, Prediction and analysis of the sea-

sonal performance of tri-generation and CO2 refrigeration systems in

supermarkets, Applied Energy, 112 (2013) 898-906.

[2] S. G. Kim, Y. J. Kim, G. Lee, M. S. Kim, The performance of a transcrit-

ical CO2 cycle with an internal heat exchanger for hot water heating,

International J. Refrigeration, 28 (2005) 1064-1072.

[3] J. Stene, Residential CO2 heat pump system for combined space

heating and hot water heating, International J. Refrigeration, 28 (2005)

1259-1265.

[4] W. Lin, N. Zhang, A. Gu, LNG (liquefied natural gas): A necessary part

in China’s future energy infrastructure, Energy, 35 (2010) 4383-4391.

[5] E. Querol, B. Gonzalez-Regueral, J. García-Torrent, A. Ramos, Available

power generation cycles to be coupled with the liquid natural gas (LNG)

vaporization process in a Spanish LNG terminal, Applied Energy, 88

(2011) 2382-2390.

[6] Y. Song, J. Wang, Y. Dai, E. Zhou, Thermodynamic analysis of a tran-

scritical CO2 power cycle driven by solar energy with liquified natural

gas as its heat sink, Applied Energy, 92 (2012) 194-203.

[7] X. L. Gu, H. Sato, Performance of supercritical cycles for geothermal

binary design, Energy Conversion and Management, 43 (2002) 961-971.

[8] S. Kaneko, K. Yamamoto, M. Kinoshita, Y. Wakabayashi, Y. Iida, Design

and operation experience of a 1000 MW ultra supercritical coal fired

boiler with steam condition of 25.4 MPa 604/602 °C, Technical Review

— Mitsubishi Heavy Industries, 36 (1999) 61-65.

[9] F. Goembira, S. Saka, Optimization of biodiesel production by super-

critical methyl acetate, Bioresource Technology, 131 (2013) 47-52.

[10] Z. Ilham, S. Saka, Optimization of supercritical dimethyl carbonate

method for biodiesel production, Fuel, 97 (2012) 670-677.


[11] J. S. Lee, S. Saka, Biodiesel production by heterogeneous catalysts

and supercritical technologies, Bioresource Technology, 101 (2010)

7191-7200.

[12] E. Minami, S. Saka, Kinetics of hydrolysis and methyl esterification for

biodiesel production in two-step supercritical methanol process, Fuel,

85 (2006) 2479-2483.

[13] S. Saka, Y. Isayama, A new process for catalyst-free production of bio-

diesel using supercritical methyl acetate, Fuel, 88 (2009) 1307-1313.

[14] S. Saka, Y. Isayama, Z. Ilham, X. Jiayu, New process for catalyst-free

biodiesel production using subcritical acetic acid and supercritical meth-

anol, Fuel, 89 (2010) 1442-1446.

[15] R. Feiner, N. Schwaiger, H. Pucher, L. Ellmaier, P. Pucher, M. Sieben-

hofer, Liquefaction of pyrolysis derived biochar: A new step towards

biofuel from renewable resources, RSC Advances, 3 (2013) 17898-17903.

[16] M. C. Johnson, J. W. Tester, Lipid transformation in hydrothermal pro-

cessing of whole algal cells, Industrial and Engineering Chemistry

Research, 52 (2013) 10988-10995.

[17] Z. Liu, A. Quek, R. Balasubramanian, Preparation and characterization

of fuel pellets from woody biomass, agro-residues and their corre-

sponding hydrochars, Applied Energy, 113 (2014) 1315-1322.

[18] H. Ramsurn, R. B. Gupta, Deoxy-liquefaction of switchgrass in super-

critical water with calcium formate as an in-situ hydrogen donor, Biore-

source Technology, 143 (2013) 575-583.

[19] Z. Fang, R. L. Smith Jr., X. Qi, Production of biofuels and chemicals

with ionic liquids, in: Biofuels and Biorefineries 1; Springer, 2013.

[20] X. Qi, M. Watanabe, T. M. Aida, R. L. Smith Jr., Catalytic conversion

of cellulose into 5-hydroxymethylfurfural in high yields via a two-step

process, Cellulose, 18 (2011) 1327-1333.

[21] X. Qi, M. Watanabe, T. M. Aida, R. L. Smith Jr., Efficient catalytic con-

version of fructose into 5-hydroxymethylfurfural in ionic liquids at room

temperature, ChemSusChem, 2 (2009) 944-946.

[22] K. Chen, M. Tamura, Z. Yuan Y. Nakagawa, K. Tomishige, One-pot con-

version of sugar and sugar polyols to n-alkanes without C-C dissociation

over the Ir-ReOx/SiO2 catalyst combined with H-ZSM-5, ChemSus-

Chem, 6 (2013) 613-621.


SCFs&T for Bio-based Fuel processes

41

wATER — A “MAGIC” TOOL TO CONVERT BIOMASS?

Andrea KruseUniversity Hohenheim;

Garbenstrasse 9, 70599, Stuttgart, BaWü, Germany; E-mail: [email protected]

Fresh biomass could be dried and combusted or gasified

by a “dry process”. Such processes are under development

and are similar to fossil coal processing. The motivation

for such R&D work is the wish to become more indepen-

dent of the vanishing fossil resources for energy supply and

chemically produced products. However, drying is asso-

ciated with considerable costs at high water content of

80-90% in green plants. On the other hand, most of the up

to now unused, and therefore most attractive, biomass has

such high water content. For such “wet” or “green” bio-

mass, hydrothermal biomass conversion methods are su-

perior. The expression “hydrothermal” is originally used

in geology to name reaction in water at increased tem-

peratures and pressures. Depending on the reaction con-

ditions, different fuels or basic chemicals, to produce e.g.

polymers, can be formed. These fuels are a solid, liquid

(with a very high viscosity) or gaseous. The selectivity

towards these products is usually higher and the tempera-

tures lower than in the analogous dry processes. The rea-

son for the lower temperature is the high reactivity of

biomass in water. The reasons for the high selectivity are

the lower temperature and the change of water properties

with reaction conditions. All hydrothermal biomass con-

version processes take benefit of the special properties of


hot compressed liquid or supercritical water. At subcritical

conditions, the ionic product of water is higher as at am-

bient conditions. The reason is the endothermic character

of the self-dissociation of water. The high H+ and OH-

concentrations enable rather high reaction rates of reac-

tions usually require the presence of acids and bases. In

other cases, water itself works as catalyst, fulfilling the

role usually done by H+ or OH-. At supercritical conditions

(above 374 °C and 22.1 MPa) water behaves like a non-po-

lar solvent but the water molecules are still polar. These

unique properties mainly avoid unwanted polymerization

by splitting large molecules and solving the products.

This hydrothermal biomass conversion processes

introduced here are:

I. Pretreatment. At lower temperatures we found dif-

ferent pre-treatment methods, e.g. simply cooking

of biomass. The (exothermic) degradation of bio-

mass starts at around 170 °C.

II. Hydrothermal Carbonization. At around 200 °C, there

are the operation conditions of hydrothermal car-

bonization (HTC) of biomass. Here artificial coal is

produced with very high yield, often in the presence

of an acid as catalyst. From the chemical point of

view and at this condition, most of the biomass is

split first. The splitting of carbohydrates like cellu-

lose and hemicelluloses is supported by the high

ionic product of water. The product, glucose con-

verts partially to fructose. If the reaction is stopped

at this point the products glucose and fructose can

be feed for microorganism. By water elimination,

hydroxymethylfurfural (HMF) from fructose is pro-

duced. HMF is an important platform chemical

which may substitute compounds from fossil oil to

SCFs&T FOR BIO-BASED FUEL PROCESSES 43

produce a wide range of products, e.g. polymers. If

the reaction is not stopped at this stage, a solid prod-

uct is formed by polymerization. This brown or black

product has nearly the heating value of fossil lig-

nite. Therefore the process is called “Carbonization”.

III. Aqueous Reforming. At slightly higher temperature

hydrogen can be produced from compounds origi-

nating from biomass using noble metal catalysts.

This process, called aqueous reforming, works be-

cause of thermodynamic reason only at very low

concentrations and up to now not with real bio-

mass. The hydrogen can be use for in-situ hydro-

genation of the feedstock to produce hydrocarbons,

if a suitable catalyst is present.

IV. Hydrothermal liquefaction. At around 300 to 350 °C

biomass liquefaction occurs. This process developed

originally by the company Shell as hydrothermal

upgrading, lead to a high viscous product with a

lower oxygen content and higher heating valve than

the product of dry biomass liquefaction (fast pyrol-

ysis). In some cases (alkali) catalysts are applied

and recently the focus is on liquefaction of algae.

A special application is the splitting of lignin to

phenols which are precursors of resins. In this case

temperatures of around 400 °C are useful. Lignin is

the only common renewable resource for aromatic

compounds, which are produced from fossil oil today.

V. Near critical gasification. Near the critical point the

catalyzed hydrothermal gasification is conducted.

Methane and CO2 are the main products and het-

erogeneous catalysts are necessary. In this tempera-

ture range methane is the main burnable product in

equilibrium, but noble metal catalysts are necessary

because methane formation is kinetically inhibited.


VI. Supercritical water gasification. This process is called

supercritical water gasification, because of the re-

actions conditions above the critical point of water.

The wished product is hydrogen. Usually tempera-

tures at or above 600 °C are applied because only

at high temperature hydrogen is the preferred prod-

uct in equilibrium. Catalysts are salts included in

the biomass. Heterogeneous, e.g. noble metals as

well as carbon catalysts are not necessary but often

used to reduce the temperature or to increase the

gas yield at higher dry mass content and concen-

trations, respectively.

Depending on the reaction conditions, a wide range

of products like different energy carriers (gaseous, liquid

or solid) or platform chemicals are available. This is a con-

sequence of the change in the water properties with tem-

perature and density. The variability of the reaction medium

is unique and is the key for the use of “wet” or “green”

biomass. Water is a natural ingredient of biomass which

becomes the reaction medium by heating-up. This typical

property of hydrothermal reactions opens a lot of possibil-

ities e.g. to combine them with biochemical reactions that

are also occurring in water. On the first view hydrothermal

processes seems to be an important tool for a “bio-refin-

ery” to produce various products by usage of the complete

plants. On the other hand there are some challenges.

Which challenges are the most important depend on the

temperature or wished product. E.g. for hydrothermal car-

bonization and hydrothermal liquefaction the treatment

of the waste water is important. For the processes using

heterogeneous catalyst, poising is the largest hurdle to

overcome. For supercritical water the strong conditions

limits the reactor material lifetime.

FUNDAMENTALS OF ThE SUPERCRITICAL wATER OxIDATION PROCESS FOR AN EFFICIENT AND CLEAN ENERGy PRODUCTION

45

FUNDAMENTALS OF ThE SUPERCRITICAL wATER OxIDATION PROCESS FOR AN EFFICIENT AND CLEAN ENERGy PRODUCTION

Maria José coceroSchool of Industrial Engineering,

Sede Mergelina Chemical Engineering Department, Valladolid University;

47011, Valladolid, Spain; E-mail: [email protected]

high pressurized water (HPW) / Supercritical water (SCW)

properties as reaction media. Water offers many favor-

able properties at elevated temperatures and pressures

that make it therefore an excellent solvent and reaction

medium for numerous applications. In the vicinity of the

critical point the thermodynamic properties of water change

drastically compared to those of liquid water [1]. The den-

sity (ρ), dielectric constant (ε) and ionic product of water

(Kw) from 0 ºC to 600 ºC at a pressure of 25 MPa can be

calculated according to the equations developed in liter-

ature [2,3]. The change in the dielectric constant is pro-

portional to the density and inversely proportional to the

temperature. Hydrogen bonds present a behavior analo-

gous to that of the dielectric constant. Another important

property of the organic reaction media is the ionic product

of water. Around 300 ºC the value of the ionic product of

water reaches its maximum (1.10-11), which creates a me-

dium with high H+ and OH- concentrations, thus favoring

in this way acid/basis catalyzed reactions. Above the crit-

ical temperature of water (374 ºC), the Kw decreases dras-

tically (1.10-25) [4]. At higher pressures (P>60 MPa) the

Kw again presents values similar to those of ambient wa-

ter. The significant drop in the dielectric strength leads to


a considerable increase in the solubility of hydrocarbons

in supercritical water. In correlation, the solubility of inor-

ganic salts reduces drastically. Supercritical water acts

like a non-polar dense gas with solvation properties equiv-

alent to those of low polar organic solvents. Additionally

the gases as CO2, O

2, N

2 are completely miscible in SCW

[1]. These physical properties are the reason to consider

supercritical water as an ideal media for the oxidation of

organic compounds. The reaction takes place in a single

phase, avoiding interfacial mass transfer resistances. Su-

percritical Water Oxidation process. The process known

as supercritical water oxidation (SCWO) consists of the ho-

mogeneous oxidation of chemical compounds in an aque-

ous medium using air, oxygen or hydrogen peroxide as

oxidizing agent, at temperatures and pressures above the

critical point of water (374 ºC and 22.4 MPa). The SCWO

takes place in three steps: Feed preparation and pressur-

ization; Reaction and solids separation; and Depressuriza-

tion and heat recovery [1]. Technically, the SCWO has the

advantage of simple, fast and homogeneous reactions

without mass transfer limitations. It also has some limita-

tions related to extreme operating conditions and their

effect on the materials equipment. Therefore, the main

challenges of SCWO are corrosion and deposition of salts,

which are being solved by the use of special construction

materials and the development of new reactor designs able

to soften the conditions that the materials must resist.

SCWO kinetic can be described by a radically reaction

mechanic, but when the temperature of the mixture is

higher than the auto ignition temperature, supercritical

water oxidation proceeds in the form of flames called hy-

drothermal flames. In general, flames ignited spontaneous-

ly beyond a certain temperature, normally between 400

and 500 ºC. This auto ignition temperature was decreased

SCFs&T FOR BIO-BASED FUEL PROCESSES 47

for higher pressures and fuel concentrations [5]. Hydro-

thermal flames are combustion flames produced in aque-

ous environments at conditions above the critical point of

water (P>221 bar and T>374 ºC).The flame is defined as

the surface where combustion is produced. This surface

separates the oxidant from the fuel in the case of diffusion

or non-premixed flames, in which fuel is injected into the

oxidant. In the case of premixed flames, that is, when the

fuel and oxidant are injected already mixed, the flame is

the surface separating the reagents from the reaction prod-

ucts. In premixed flames, the surface is moving towards

the reagents with a flame front velocity. If this velocity

is the same as the fluid velocity the flame will remain still

in a fixed position. In general, the conditions of the flame

ignition depended on the fuel, the oxidant, and the ratio

of fuel/oxidant and the geometry of the injection system.

SCWO with a hydrothermal flame has a number of advan-

tages over the flameless process. Some of these advan-

tages permit overcoming the traditional challenges that

make the successful and profitable commercialization of

SCWO technology difficult [6]:

� Allow the destruction of the pollutants in residence

times of a few milliseconds: construction of small-

er reactors.

� Reaction with feed injection temperatures near to

room temperature, avoids problems such as plug-

ging and corrosion in a preheating system and ad-

vantages from the operational and energy integration

perspective.

� Higher operation temperatures, improve the energy

recovery Energy by supercritical water oxidation.


The research group has been very active in the de-

veloping of SCWO process as an efficient and environmen-

tal compatible process for the treatment of wastes [1]. The

SCWO process can reduce significantly the operation time

by using hydrothermal flames. The results showed that

the SCWO technology, using hydrothermal flame, is able

to oxidize high amounts of compounds in residence times

of around 1s, using very compact reactors and producing

CO2, water, salts and energy [7]. Our last contribution is a

new reactor to produce energy. A 650 ºC up-reactor efflu-

ent can be combined with a gas turbine to produce work

and energy. For example, by using the conventional Rankin

cycle to produce 1 MW by SCWO reactor effluent, the pump

and air compressor consume 1,64 MW. The new reactor

allows the production of 1 MW by consuming 0,78 MW, so

this could be a way of producing neat excess energy [8].

REFERENCES.

[1] M. D. Bermejo, M. J. Cocero, AIChE J., 52 (2006) 3933-3951.

[2] W. L. Marshall, E. U. Franck, J. Physical and Chemical Reference Data,

10(2) (1981) 295-304.

[3] M. Uematsu, E. U. Franck, J. Physical and Chemical Reference Data,

9(4) (1980) 1291-13.

[4] N. Akiya, P. E. Savage, Chemical Reviews, 102(8) (2002) 2725-2750.

[5] W. Schilling, E. U. Franck, Berichte der Bunsengesell-schaft für physi-

kalische chemie, 92 (1988) 631-636.

[6] C. Augustine, J. W. Tester, Hydrothermal flames: From phenomeno-

logical experimental demonstrations to quantitative understanding, J.

Supercritical Fluids, 47 (2009) 415-430.

[7] M. D. Bermejo, C. Jiménez, P. Cabeza, A. Matías-Gago, M. J. Cocero,

J. Supercritical Fluids, 59 (2011) 140-148.

[8] P. Cabeza, M. D. Bermejo, C. Jiménez, M. J. Cocero, Water Research,

45(8) (2011) 2485-2495.


SCFs&T for New Materials and Materials Processing

51

AEROGELS OF DIFFERENT ORIGINS: A JOURNEy FROM INSULATION MATERIALS TO ADDED-VALUE PRODUCTS OF BIOREFINERy

irina smirnovaUniversity of Technology Hamburg-Harburg;

Eissendorferstr. 38, 21075, Hamburg, Germany; E-mail: [email protected]

Aerogels are known as a special class of nanoporous ma-

terials already since 1930. They are obtained from wet gels

by using a suitable drying technology, usually a supercrit-

ical drying process, able to avoid the pore collapse phe-

nomenon and keep intact the porous texture of the wet

material. Efforts have been traditionally focused on silica

aerogel and carbon aerogel development with a wide range

of applications in different fields, e.g., aeronautics, bio-

medicine, construction, environmental remediation or ag-

riculture. However, among the broad range of possible

applications, just few of them have been commercialized

so far. Main application is the thermal insulation due to

the extremely low thermal conductivity of aerogels. The

main issues behind this situation are the production costs,

associated with the raw materials and with supercritical

fluid extraction needed for the synthesis of aerogels with

low density. Regarding the raw materials, in the last de-

cades it was realized, that aerogels may be produced from

a great variety of different organic and inorganic materials

and are not restricted by traditional matrices like silica or

carbon ones. Moreover, a lot of biopolymers, having an

advantage of biocompatibility were successfully trans-

ferred in an aerogel form. Generally, all materials that can

be obtained as wet gels by the sol-gel process are potential


candidates to be turned into aerogels after supercritical

drying. New aerogel classes become especially interested

as intelligent insulation materials, allowing to reduce the

thickness of the insulation significantly. Furthermore,

the applications in the pharmaceutical and food areas

seem to be promising even in front of higher production

costs. Also a combination of the aerogels production with

the biorefinery processes can be realized by using of biore-

finery products as raw materials for gelation. This was for

instance demonstrated by using lignin as a precursor. So

far it seems that the outstanding properties of the aerogels

of different origins significantly broaden the spectrum of

their applications and open a way to their commercializa-

tion. On the way from the lab to the production the scale

up of the supercritical extraction step is the main issue.

Here the energy demand can be dramatically reduced by

optimization of the extraction process, which is currently

the main task for aerogel commercialization. Supercritical

extraction (or drying process) overcomes the problems en-

countered with traditional drying methods and preserves

the high open porosity and superior textural properties

of the wet gel in a dry form. Supercritical CO2 is the most

appropriate fluid for supercritical drying of organic aero-

gels due to its mild critical point conditions along with its

GRAS status. However, depending on the sample size and

thickness the residence time in the extractor might be

significant. Here significant efforts for the modeling of the

process with the aim of the process optimization are still

needed.

53

SUPPORTED METALLIC NANOPARTICLES By SUPERCRITICAL DEPOSITION AND ThEIR APPLICATIONS IN ENERGy RELATED TRANSFORMATIONS

can ErkeyDepartment of Chemical and Biological Engineering,

Koç University; 34450 Sarıyer, Istanbul, Turkey;


Techniques such as impregnation, co-precipitation and

sol-gel are commonly used to prepare supported nanopar-

ticles. However, it is generally difficult to control the phys-

ical properties of the particles, such as the particle size

and distribution, and the metal concentration in the ma-

terials. The supercritical deposition (SCD) technique in-

volves the dissolution of a metal precursor in a supercritical

fluid (SCF) and the exposure of a substrate to the solution.

After adsorption of the precursor on the substrate surface,

the metallic precursor is converted to its metal form using

a number of methods resulting in nanoparticles at the sur-

face of the substrate. Supercritical deposition especially

using supercritical carbon dioxide (scCO2) has numerous

advantages including the elimination of organic solvents

and solvent residue on the substrates. Furthermore, fast-

er mass transfer rates compared to liquids result in faster

rates of deposition.

A wide variety of metal nanoparticles including Pt,

Ru, Ni, and Cu@Cu2O were prepared using SCD on a wide

variety of porous substrates including alumina, silica, car-

bon nanotubes, carbon and resorcinol formaldehyde aero-

gels. Uniformly distributed nanoparticles with a narrow

particle size distribution are often obtained using SCD.


The size of the nanoparticles can be tuned by adjusting

the supercritical deposition parameters such as metal pre-

cursor concentration in the fluid phase, temperature and

the pressure of precursor adsorption, and the reduction

temperature. The nature of the support material is also an

important factor which effects the morphology of the nano-

particles. The thermodynamics of adsorption of the metal

precursors are generally quantified by the adsorption iso-

therms for the precursors between the fluid phase and the

porous substrate which usually follow Langmuir behavior.

The kinetics of adsorption can adequately be described

by using a mass transfer model based on diffusion in pore

volume and local equilibrium at the surface of the support.

In some cases, catalysts prepared using this technique

have been found to be superior in activity to catalysts pre-

pared by conventional techniques.

The technique has recently been extended to prepa-

ration of supported bimetallic nanoparticles. Simultaneous

Supercritical Deposition involves the dissolution of two

metal precursors in a SCF and exposure of a substrate to

this solution. Metal precursors are then physisorbed or

chemisorbed on the support in the presence of SCF. Ad-

sorbed metal precursors can then be decomposed to end

up with supported metals or metal oxides through various

processes. Carbon aerogel supported Pt-Cu alloy nano-

particles were prepared using the precursors dimethyl

(1,5-cyclooctadiene), platinum (II) (Pt(cod)me2) and bis

(1,1,1,3,5,5,6,6,6-nonafluorohexane-2,4-diiminate) copper

in the presence of scCO2. Binary adsorption isotherms were

successfully predicted using the Ideal Adsorbed Solution

Theory by using single component adsorption isotherm

parameters alone. Alloy nanoparticles were formed via

the thermal decomposition of metal precursors. The alloy-

ing of Pt and Cu within the nanoparticles was character-

SCFs&T FOR NEw MATERIALS AND MATERIALS PROCESSING 55

ized via XRD peak shifts at various Pt/Cu ratios, and XPS

data pointed out that the surfaces of these Pt-Cu alloy

nanoparticles were enriched in Pt. The particle size of the

nanoalloys was found to increase with increasing copper

fraction. Nevertheless, the particle size distribution was

very uniform in all cases.

Reactive supercritical deposition where the precur-

sors chemisorb on the surface by reacting with the func-

tional groups on the surface is another variation of the

technique which can be used to prepare bimetallic sys-

tems. Recently, USY zeolite supported Ni-W hydrocracking

catalysts were prepared via the simultaneous chemisorp-

tion of tungsten hexacarbonyl (W(CO)6) and Nickel (II)

acetylacetonate or bis (1,1,1,3,5,5,6,6,6-nonafluorohex-

ane-2,4-diiminate) nickel in the presence scCO2. Materials

were then calcined at ambient pressure. FTIR indicated

the chemisorption of metal precusors on USY zeolites. XRF

analysis showed an increase in the W loading with an

increase in both the initial W(CO)6 concentration in scCO

2

and the deposition time. Temperature Programmed De-

sorption experiments carried out using ammonia suggest-

ed that at the same loading the acid site distribution was

different from catalyst prepared by incipient wetness. More-

over, the proportion of the stronger acid sites was higher

for the catalysts prepared using simultaneous supercritical

deposition (53.3% of the total acid sites) as compared to

that of the incipient wetness (33.2% of the total acid sites)

indicating that the technique has potential to lead to de-

velopment of catalysts with properties that are different

than catalysts prepared by conventional techniques.

57

DENSE CO2 AS AN ENABLING MEDIUM FOR INTENSIFIED CATALyTIC AND PARTICLE FORMATION PROCESSES

Bala subramaniamCenter for Environmentally Benefi cial Catalysis,

University of Kansas; 1501 Wakarusa Drive, Suite A110, 66047, Lawrence, KS, USA;


The foremost guiding principles underlying the sustain-

able process development include process intensification

at mild conditions, minimization of waste and of adverse

environmental footprints, and enhancement of inherent

process safety [1]. Many groups, including ours, have

uniquely exploited near-critical media to develop novel

catalytic process concepts that admit these attributes.

Central to these innovations is the recognition that with

relatively moderate changes in pressure, it is possible to

“tune in” unique fluid properties (liquid-like density and

gas-like transport) with near-critical media. These con-

cepts have numerous novel applications in heterogeneous

catalysis such as: (a) facile desorption and transport of

heavy molecules (including coke precursors) in mesoporous

catalysts, alleviating pore-diffusion limitations and im-

proving catalyst effectiveness; (b) enhancing product se-

lectivity; and (c) exploiting the enhanced heat capacity of

near-critical media to ameliorate parametric sensitivity in

exothermic reactions. These features have been demon-

strated for several classes of reactions such as isomeri-

zations, hydrogenations, Fischer-Trøpsch synthesis and

alkylations [1].

During the past decade, our group has exploited

the pressure-tunable properties of gas-expanded liquids


(GXLs) in a variety of homogeneous catalytic systems [2].

At ambient temperatures, gases such as carbon dioxide

(CO2) and light hydrocarbons (such as propylene and eth-

ylene) are close to their critical temperatures (i.e., between

0.7 -1.3 Tc). When these gases are mildly compressed (to

tens of bars) at ambient temperatures, they dissolve in

most conventional solvents and volumetrically expand

them. The increased free volume of the GXL phases ac-

commodates permanent gases such as O2, H

2 and CO in

unusually high concentrations. For example, O2 and light

olefin concentrations are increased by one or two orders

of magnitude in GXLs at ambient conditions, relative to

conventional solvents, with similar increases in reaction

rates [3].

This lecture will also highight several novel GXL-

based catalytic reaction engineering concepts. These in-

clude (a) highly selective hydroformylation of higher olefins

at mild conditions (~40 bars, 60 °C) employing soluble

polymer-supported homogeneous catalysts which are eas-

ily retained in solution by membrane filtration [4]; (b) in-

herently safe liquid phase ethylene epoxidation process

that totally eliminates CO2 formation as a byproduct [5];

(c) a spray reactor concept for the single step formation of

high purity terephthalic acid with reduced solvent burning

(i.e., reduced carbon footprint) [6].

Supercritical CO2 has also been exploited to synthe-

size nanomaterials of active pharmaceutical ingredients

[7] and transition metal complexes with unique function

[8]. This talk will describe a continuous GMP-compliant

process for producing nanoparticles.

REFERENCES

[1] B. Subramaniam, C. J. Lyon and V. Arunajatesan, Applied Catalysis B:

Environmental, 37(4) (2002) 279-292.


[2] P. G. Jessop and B. Subramaniam, Chemical Reviews, 107(6) (2007)

2666-2694.

[3] M. Wei, G. T. Musie, D. H. Busch and B. Subramaniam, J. American

Chemical Society, 124(11) (2002) 2513-2517.

[4] Z. Xie, J. Fang, S. K. Maiti, W. K. Snavely, J. A. Tunge and B. Subrama-

niam, AIChE J. (2013) DOI: 10.1002/aic.14142.

[5] M. Ghanta, H-J Lee, D. H. Busch and B. Subramaniam, AIChE J., 59

(2013) 180-187.

[6] M. Li, F. Niu, X. Zuo, P. D. Metelski, D. H. Busch and B. Subramaniam,

Chemical Engineering Science (2013). Available in: http://dx.doi.org/

10.1016/j.ces. 2013.09.004i.

[7] B. Subramaniam, R. A. Rajewski and W. K. Snavely, J. Pharmaceutical

Sciences, 86 (1997) 885-890.

[8] C. A. Johnson, S. Sharma, B. Subramaniam and A. S. Borovik, J. Ameri-

can Chemical Society, 127(27) (2005) 9698-9699.

PROCESSING AND PRODUCTION OF NEW DRUGS AND ChEMICALS WITh COMPRESSED FLUIDS

61

PROCESSING AND PRODUCTION OF NEW DRUGS AND ChEMICALS WITh COMPRESSED FLUIDS

nora ventosa, santi sala, Elisa Elizondo, María Muntó, ingrid cabrera, Alba córdoba, Evelyn Moreno,

paula Rojas, Lidia ferrer, Jaume vecianaInstitut de Ciència de Materials de Barcelona (CSIC)

and Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN);

Campus Universitari de Bellaterra, E-08193 Cerdanyola, Spain; E-mail: [email protected]

The obtaining of particulate micro and nanostructured

molecular materials at large scale and the understanding

of how to manipulate them at nanoscopic and supramo-

lecular level are currently playing a crucial role in drug

delivery and clinical diagnostics [1-3]. It has been observed

that polymeric nanoparticles, micelles, microemulsions,

nanosuspensions, nanovesicles, and nanocapsules are ef-

ficient drug carriers that can significantly help to develop

new drug delivery routes, more selective and efficient dis-

ease-detection systems, drugs with a higher permeability

to biological membranes with controlled released profiles,

and to enhance their targeting towards particular tissues,

cells or intracellular compartments.

The potential of “bottom-up” strategies, based on

molecular self-assembling, is much larger than that of

“top-down” approaches for the preparation of such micro-

and nanostructures. For instance, by precipitation proce-

dures it should be possible to control particle formation,

and hence particle size and size distribution, morphology

and particle supramolecular structure. However, conven-

tional precipitation/crystallizations from liquid solutions


have serious limitations and are not adequate for produc-

ing such nanoparticulate materials at large scale with the

narrow structural variability, high reproducibility, purity

and cost needed to satisfy the high-performance require-

ments and regulatory demands dictated by the EMA and

US FDA agencies.

The solvent power of compressed fluids (CFs), either

in the liquid or supercritical state, can be tuned by pres-

sure changes, which propagate much more quickly than

temperature and composition solvent changes. Therefore,

using compressed solvent media, it is possible to obtain

supramolecular materials with unique physicochemical

characteristics (size, porosity, polymorphic nature morphol-

ogy, molecular self-assembling, etc.) unachievable with

classical liquid media [4]. Small changes in temperature

and pressure of CFs result in large but homogenous chang-

es in the fluid’s density, and hence in its solvent power.

This tunable range in density (solvation ability) cannot be

achieved so easily with any conventional liquid solvent.

The most widely used CF is compressed CO2 (cCO

2), which

is non-toxic, non-flammable, cheap and easy recyclable.

It has gained considerable attention, during the past few

years as a “green substitute” to organic solvents and even

to water in industrial processing. During the past few years,

CFs based technologies, in particular precipitation proce-

dures, are attracting increasing interest for the preparation

of particulate molecular materials with application in the

field of drug-delivery and nanomedicine [5-10].

In this presentation a simple one-step and scale-up

methodology for preparing multifunctional nanovesicle -

bioactive conjugates will be presented. This method is

readily amenable to the integration/encapsulation of mul-

tiple components, like peptides, proteins, enzymes, into

the vesicles in a single-step yielding sufficient quantities


for clinical research becoming, thereby, nanocarriers to be

used in nanomedicine for drug delivery purposes. A cou-

ple of examples of novel nanomedicines prepared by this

methodology will be presented and their advantages dis-

cussed [11,12].

REFERENCES

[1] M. E. Davis, Z. Chen, D. M. Shin, Nature Reviews-Drug Discovery, 7

(2008) 771-782.

[2] P. Couvreur, C. Vauthier, Pharmaceutical Research, 23 (2006) 1417-1450.

[3] D. Peer, J. M. Karp, S. Hong, O. C. Farokhzad, R. Margalit, R. Langer,

Nature Nanotechnology, 2 (2007) 751-760.

[4] E. Reverchon, R. Adami, J. Supercritical Fluids, 37 (2006) 1-22.

[5] K. Mishima, Advanced Drug Delivery Reviews, 60 (2008) 411-432.

[6] M. Cano-Sarabia, N. Ventosa, S. Sala, C. Patiño, R. Arranz, J. Veciana,

Langmuir, 24 (2008) 2433-2437.

[7] E. Elizondo, S. Sala, E. Imbuluzqueta, D. González, M. J. Blanco-Prie-

to, C. Gamazo, N. Ventosa, J. Veciana, Pharmaceutical Research, 28

(2011) 309-321.

[8] E. Moreno-Calvo, M. Muntó, K. Wurst, N. Ventosa, N. Masciocchi, J.

Veciana, Molecular Pharmacology, 8 (2011) 395-404.

[9] S. Sala, A. Córdoba, E. Moreno-Calvo, E. Elizondo, M. Muntó, P. Rojas,

Mª A. Larrayoz, N. Ventosa, J. Veciana, Crystal Growth Design, 12 (2012)

1717-1726.

[10] E. Elizondo, J. Larsen, N. Hatzakis, I. Cabrera, J. Ingrid, J. Veciana, D.

Stamou, N. Ventosa, J. American Chemical Society, 134 (2012) 1918-

1921.

[11] N. Ventosa, L. Ferrer-Tasies, E. Moreno-Calvo, M. Cano, M. Aguilella-

Arzo, A. Angelova, S. Lesieur, S. Ricart, J. Faraudo, J. Veciana, Lang-

muir, 29 (2013) 6519-6528.

[12] I. Cabrera, E. Elizondo, E. Olga; J. Corchero, M. Mergarejo, D. Pulido,

A. Cordoba, E. Moreno-Calvo, U. Unzueta, E. Vazquez, I. Abasolo, S.

Schwartz, A. Villaverde, F. Albericio, M. Royo, M. Garcia-Parajo, N.

Ventosa, J. Veciana, Nano Letters, 13 (2013) 3766-3774.

hyPOLIPEMIANT, ANTI-OBESITy AND ANTITUMOR ACTIVITIES OF SUPERCRITICAL ExTRACTS

65

hyPOLIPEMIANT, ANTI-OBESITy AND ANTITUMOR ACTIVITIES OF SUPERCRITICAL ExTRACTS

sandra R. s. ferreiraDepartment of Chemical and Food Engineering,

Federal University of Santa Catarina (UFSC), EQA/CTC; CP 476 – Trindade, 88040-900, Florianópolis, SC, Brazil;


Natural products are a large source of components with

biological activities. Those substances normally present

high aggregated value and are important for different ar-

eas such as medicinal, food and nutritional supplements.

On the other hand, obesity is a serious public health prob-

lem and is an important risk factor associated with the

increase of cardiovascular disease, diabetes, chronic kid-

ney disease, and some types of cancers. Overweight and

obesity are associated with different conditions including

hypertriglyceridemia and hypercholesterolemia which are

caused by a disorder in the lipid metabolism and promote

modifications in serum lipoprotein. Efforts towards the

development of new effective drugs led to the discovery

of hypolipidemic therapeutic agents from natural sources,

which also raise interest for cancer treatment, because

the therapies available are not completely able to reduce the

disease progression and/or present high toxicity. Further-

more, hypolipidemic or antihyperlipidemic agents are a

diverse category of pharmaceuticals that are used for treat-

ment of hyperlipidemia, which means an excess of cho-

lesterol, triglycerides and glucose levels.

In the present work different extracts from natural

products were evaluated for their hypolipemiant, anti-obe-


sity and antitumor abilities and the raw materials tested

to provide the extracts varied from marine wildlife sourc-

es (pink shrimp residue) to medicinal plants (Cordia ver-

benacea and Casearia sylvestris). There are several usual

procedures to obtain the extracts with biological active

compounds from natural sources, such as low pressure

(LP) methods and also supercritical (SC) technology. These

procedures present advantages and disadvantages, and

the effectiveness of each technique depends on the prod-

uct quality and application, allied with the economical

viability of the process. The anti-obesity and the hypolip-

idemic effects of the extracts (from pink shrimp residue

and from C. sylvestris) were evaluated in vivo by means

of submitting mice species (Swiss Mus musculus normal,

Balb C and knocaut) to different assays. The anti-obesity

characteristic was observed by treating the mice with a

high-fat diet combined with the administration of the nat-

ural product extracts (from LP and SC processes) by oral

gavage doses during 30 days. All animal procedures were

conducted in accordance with legal requirements appro-

priate to the species and approved by local ethics com-

mittee. The weight of the animals during the treatment

and the final total serum cholesterol, triglycerides and

glucose levels were also monitored by means of mice blood

analysis after the high fat diet treatment. The results in-

dicated that the diet using SC extracts from shrimp residue

at 50-100 mg/kg.d showed the best anti-obesity effect for

knocaut and for normal mice, compared to LP extracts.

The same behavior was performed by SC extracts from C.

sylvestris, which presented the lowest mice body weight

gain (best anti-obesity performance). Additionally, the nor-

mal mice group presented lower triglycerides and choles-

terol levels, compared to knocaut when the shrimp residue

extracts were applied. The best efficiency on triglycerides

reduction observed from mice group treated with SC shrimp


extract was probably due to a synergistic action of astax-

anthin, eicosapentaenoic (EPA) and docosahexanoic (DHA)

fatty acids present in the extract. Additionally, highest

glucose and triglycerides reductions were observed in an-

imals treated with SC extracts from C. sylvestris, compared

to the mice group treated with LP extract. Medicinal plants,

such as C. verbenacea and C. sylvestris, have multiple

popular uses in Brazil and other American countries, and

are indicated for tumor treatment. In this study, SC extracts

and LP extracts from both plants were tested to evaluate

cytotoxic, antiproliferative, antitumor, nucleasic, antian-

giogenic and apoptotic activities using experimental mod-

els in vitro and in vivo. To achieve this goal, experiments

were performed evaluating the cytotoxic activity (MTT) in

vitro by the viability of MCF-7 (breast cancer) cells and

T-24 (urinary bladder carcinoma) cells. Besides, the effect

of extracts on plasmid DNA through the nuclease activity

was also evaluated. The in vivo antitumor activity was

performed in Balb/C mice inoculated with ascitic Ehrlich

tumor (AET) treated with the extracts at different concen-

trations and through the antiangiogenic activity of Gallus

domesticus eggs fertilized by the chorioallantoic mem-

brane essay (CAM) at concentrations of 1, 5 and 10 mg/

kg/day. The proapoptotic ability was also evaluated by

annexin V essay using flow cytometry in AET cells taken

from mice after extracts treatment. The results for SC ex-

tracts of C. Sylvestris reduced significantly the viability of

MCF-7 and T-24 cells. Regarding the nuclease activity

assessment, the SC extract showed a direct dose-depen-

dent damage on DNA. The in vivo assays demonstrated

that SC extracts of C. Sylvestris provided considerable

antitumor activity. The extracts treatment caused signif-

icant inhibition of tumor growth in mice, causing increase

in the average percentage of mice longevity (PAL). The an-

nexin V essay revealed that the induced cell death by


C. Sylvestris SC extracts was either by apoptosis or by

necrosis. The SC extracts of C. Sylvestris also presented

antiangiogenic activity by reducing significantly the per-

centage of blood vessels around the embryo.

The results for SC extract of C. verbenacea provid-

ed a significant improvement in the cytotoxity effect for

MCF-7 and EAC cells, and this high cytotoxity potential

of the SC extract is due to the presence of α-humulene

and trans-caryophyllene, which presents anti-inflamma-

tory activity. C. verbenacea SC extract showed higher pro-

apoptotic efficiency, by increasing 15% of unviable cells

compared to LP extract. Interestingly, in none of the treat-

ments the presence of necrotic cells was observed, sug-

gesting a specificity of the treatment effect. One possible

mechanism for the antitumor effect of SC extract of C.

verbenacea can be attributed to the property of inhibiting

COX-2 (ciclooxigenase-2 expression), which can activate

the apoptosis of tumor cells, preventing their proliferation.

Also, both C. verbenacea extracts (SC and LP) showed a

high potential for inhibition of tumor growth in mice com-

pared with the negative control, however the SC extract

presented the best performance.

Additionally, the best results obtained by the SC

extract from C. verbenacea suggest that the cytotoxicity,

as well as the antiproliferative, pro-apoptotic and antitu-

mor activities could be attributable to the high content of

α-humulene and trans-caryophyllene. The approach to

evaluate the medicinal ability of natural extracts, described

here by hypolipemiant, anti-obesity and antitumor activ-

ities, is important to reinforce the supercritical technology

as a relevant process alternative to obtain valuable sub-

stances. The high-quality behavior described by the su-

percritical extracts emphasizes the need to continually

open the areas of application of the supercritical fluids.


SCFs&T for Green Chemistry and Sustainable Technology

NEw DEVELOPMENTS AND RESEARCh IN CO2 CAPTURING

71

NEw DEVELOPMENTS AND RESEARCh IN CO2 CAPTURING

María francisco, Adriaan van den Bruinhorst, Lawien f. Zubeir, cor J. peters*, Maaike c. Kroon

Department of Chemical Engineering and Chemistry, Separation Technology Group,

Eindhoven University of Technology; Den Dolech 2, 5612 AZ Eindhoven, Netherlands;

E-mail: [email protected] *The Petroleum Institute,

Chemical Engineering Department;P.O. Box 2533, Abu Dhabi, U.A.E.;


Over the past years, the increasing concern about global

warming encouraged the scientific community to search

and develop “zero emission” processes [1]. In this context,

the reduction of carbon dioxide (CO2) release to the atmo-

sphere became one of the most challenging research in-

terests, because CO2 is considered to be the major cause

of the greenhouse phenomenon.

The removal of CO2 from natural gas or the captur-

ing of CO2 from flue gas, produced by post-combustion

industries, became a big challenge due to the large vol-

umes of CO2 and often the low CO

2 concentration in the

source gases. Most of the commercial absorption process-

es for CO2 use different types of alkanolamine solvents such

as monoethanolamine (MEA), diethanolamine (DEA) or

N-methyldiethanolamine (MDEA) [2]. Despite their good

performance as solvents for chemical absorption, amine

technologies show several important drawbacks in terms

of operational cost, solvent regeneration and the suscep-

tibility of amines to undergo thermal or oxidative degra-

dation. The emissions of amines and degradation products


to the atmosphere can cause serious damage to the envi-

ronment as well as human health [3]. For this reason, the

study of properties like their volatility became a very im-

portant issue for any work on solvent design in this area [4].

Three main approaches were found towards the de-

velopment of new “green” solvents in carbon capture [5]:

a) The use of safer solvents for health and environ-

ment, e.g., solvents showing high biodegradability;

b) The use of so-called “bio-solvents” produced from

readily available renewable resources;

c) The substitution of volatile organic solvents by less

volatile ones such as ionic liquids (ILs) with negli-

gible vapor pressure and, so far, with no detectable

emissions into the atmosphere.

ILs attracted particular attention over the past years

because they can be designed by choosing the cation-an-

ion combination to pursuit the best performance as sol-

vents for a certain application [6]. Together with their, in

general, extremely low volatility, the so-called “Task Spe-

cific Ionic Liquids” show promising advantages for CO2

capture compared to the conventional solvents. Examples

include the more suitable physico-chemical properties and

the higher degree of control of the solubility of gases in the

IL. However, the “green” character of ILs can be questioned

because most of them are produced from fossil resources

and their synthesis cannot be considered as being “green”.

Moreover, the high production and purification cost do not

make ILs technology competitive with traditional solvents

[7,8].

To overcome some of the limitations of ILs, Deep

Eutectic Solvents (DES) were revealed by Abbott as ver-

satile alternatives [9]. These low transition temperature

SCFs&T FOR GREEN ChEMISTRy AND SUSTAINABLE TEChNOLOGy 73

mixtures (LTTMs) consist of at least one hydrogen bond

donor (HBD) and one hydrogen bond acceptor (HBA) coun-

terpart resulting in the formation of a liquid mixture show-

ing an unusual low freezing point. Due to the high hydrogen

bonding interaction, some of the promising characteristics

of ILs as solvents are shared by DESs. They often possess

an extremely low volatility, and their properties can be

adjusted by selecting the nature and ratio of the hydrogen

bonding pairs. They can also be designed to show a wide

liquid range, water-compatibility, non-flammability, non-

toxicity, biocompatibility or biodegradability. Finally, they

can be easily prepared from readily available starting ma-

terials and becoming a competitive solvent in terms of

cost.

The first DES reported by Abbott [10] was formed

by mixing urea with choline chloride. Since then, other

similar DESs were prepared [11,12] and applied to differ-

ent purposes as solvents or catalysts in reactions or bio-

transformations [13], liquid separations [14] and metal

electro-deposition [15]. Not much is known about these

liquid mixtures; only the firstly reported one was very well

characterized and studied. Taking advantage of the abil-

ity to tailor the phase behavior and physical properties of

DES, studies on new combinations of hydrogen bond donor:

acceptor have to be explored for the optimization of their

performance as solvents for a certain application. The ef-

fect of different variables on their physical properties like

temperature, water content or composition need to be in-

vestigated, as well as the thermodynamic parameters gov-

erning their phase behavior. To the best of our knowledge,

the only DES explored for CO2 capture and reported in

literature is also the choline chloride + urea mixture [16].

In the search for eco-friendly and bio-renewable

solvents, new mixtures have been investigated in this study.


For that purpose, a new combination of choline chloride

with a natural organic acid is studied. The choline cation

was already explored for CO2 capture forming part of so-

called “natural ionic liquids” [17], but never in a combina-

tion with an organic acid. The choline chloride salt presents

the advantage over choline-based ILs of being a readily

available starting material as it is considered as one of the

essential nutrients in nature. The chosen organic acid is

lactic acid, a natural carboxylic acid present in milk and

vegetables, which can be easily produced by fermentation

of carbohydrates [18]. The new type of low transition tem-

perature mixtures in this work are formed by mixing both

starting materials, i.e. choline chloride and lactic acid, in

different ratios. A complete study on physical properties

like density, viscosity, surface tension, and glass transition

temperature has been executed in this work. In addition,

the CO2 solubility in these liquid mixtures is studied to

explore their suitability for CO2 capturing.

An important parameter of a solvent for capturing

CO2 is the loading capacity of the solvent. However, a pa-

rameter equally important is the rate of dissolution of the

gas in the solvent. In case the absorption rate is low, this

will lead to quite large absorption facilities. In order to

influence the kinetics of the absorption process, another

aspect of this research comprises the application of high-

gravity (HiGee) forces to reach thermodynamic equilibrium

in a relatively short time, leading to much smaller sepa-

ration units, which even can become mobile [19].

REFERENCES

[1] P. T. Anastas, M. M. Kirchhoff, Accounts of Chemical Research, 35

(2002) 686.

[2] N. MacDowell, N. Florin, A. Buchard, J. Hallett, A. Galindo, G. Jackson,

C. S. Adjiman, C. K. Williams, N. Shah, P. Fennell, Energy Environmen-

tal Science, 3 (2010) 1645.


[3] J. J. Renard, S. E. Calidonna, M. V. Henley, J. Hazardous Materials,

108 (2004) 29.

[4] P. G. Jessop, Green Chemistry, 13 (2011) 1391.

[5] C. Capello, U. Fischer, K. Hungerbühler, Green Chemistry, 9 (2007)

927.

[6] R. D. Rogers, K. R. Seddon, Science, 302 (2003) 792.

[7] S. Zhu, R. Chen, Y. Wu, Q. Chen, X. Zhang, Z. Yu, Chemical and Bio-

chemical Engineering Quaterly, 23 (2009) 207211.

[8] X. Zhang, X. Zhang, H. Dong, Z. Zhao, S. Zhang, Y. Huang, Energy

Environmental Science (2012).

[9] A. P. Abbott, D. Boothby, G. Capper, D. L. Davies, R. K. Rasheed, J.

American Chemical Society, 126 (2004) 9142.

[10] A. P. Abbott, G. Capper, D. L. Davies, R. K. Rasheed, V. Tambyrajah,

Chemical Communications, 70 (2003).

[11] Y. H. Choi, J. van Spronsen, Y. Dai, M. Verberne, F. Hollmann, I. W. C.

E. Arends, G. J. Witkamp, R. Verpoorte, Plant Physiology, 156 (2011)

1701.

[12] M. Francisco, A. van den Bruinhorst, M. C. Kroon, Green Chemistry

(2012).

[13] P. Domínguez de María, Z. Maugeri, Current Opinion in Chemical Bi-

ology, 15 (2011) 220.

[14] M. A. Kareem, F. S. Mjalli, M. A. Hashim, I. M. AlNashef, Fluid Phase

Equilibria (2012).

[15] P. Cojocaru, L. Magagnin, E. Gomez, E. Vallés, Materials Letters (2011).

[16] X. Li, M. Hou, B. Han, X. Wang, L. Zou, J. Chemical & Engineering

Data, 53 (2008) 548.

[17] M. J. Muldoon, S. N. V. K. Aki, J. L. Anderson, J. N. K. Dixon, J. F.

Brennecke, J. Physical Chemistry B, 111 (2007) 9001.

[18] B. Dien, N. Nichols, R. Bothast, J. Industrial Microbiology & Biotech-

nology, 27 (2001) 259.

[19] Liang-Liang Zhang, Ji-Xin Wang, Yang Xiang, Xiao-Fei Zeng, Jian-Feng

Chen, Industrial & Engineering Chemistry Research, 50 (2011) 6957-

6964.

COMBINING IONIC LIqUIDS AND COMPRESSED GASES FOR SUSTAINABLE PROCESS AND ENERGy ENGINEERING APPLICATIONS

77

COMBINING IONIC LIqUIDS AND COMPRESSED GASES FOR SUSTAINABLE PROCESS AND ENERGy ENGINEERING APPLICATIONS

Aaron M. scurtoDepartment of Chemical & Petroleum Engineering,

University of Kansas; 1530 W. 15th St., 4132 Learned Hall, 66045, Lawrence, KS, USA;


Ionic liquids (ILs) are experiencing intense research focus

due to their molecular flexibility producing a wide range

of properties useful as solvents and functional materials.

While their human and environmental impacts vary widely,

their exceedingly-low volatility eliminates fugitive emis-

sions which is one of the largest forms of industrial solvent-

based pollution. Combining compressed or supercritical

gases with ionic liquids has a number of beneficial effects

for reactions, separations, and energy applications. Ionic

liquids are insoluble in the majority of compressed gases

except for the most polar gases at high pressures. More-

over, these processes may have lower human and envi-

ronmental impact than some conventional processes. Here,

several of our group’s projects ranging from organic and

homogeneous catalyzed reactions, to separations, novel

absorption refrigeration, and novel Rankine/Power cycles,

etc. will be overviewed. The synthesis of ionic liquids

themselves in supercritical (SCF) or CO2-expanded solvents

(CXLs) have been investigated and shown to have a num-

ber of processing advantages over conventional solvents

especially the possibility to combine reaction and sepa-

ration. Ionic liquids have negligible solubility in com-

pressed CO2 while the reactants can be made miscible/

critical with CO2. CO

2-expanded reaction mixtures also

have control over reaction and separation with interme-


diate vapor-liquid-liquid equilibrium. Other CXLs using

polar aprotic solvents such as DMSO can be leveraged to

provide high kinetic rates and easy separation. When com-

paring the complete life-cycle analyses of IL synthesis,

both SCF and CXLs have advantages over conventional

liquid processes. Biphasic Systems with Ionic liquids and

compressed CO2 can provide an interesting platform for

reactions and separations involving such homogeneous-

ly-catalyzed reactions as hydrogenation and hydroformy-

lation. Here, the ionic liquid acts as a support phase for

the soluble catalyst and the temperature and pressure of

the compressed CO2 phase affects the partitioning of re-

actants and products and increases the mass transfer rates

into the IL phase. Alternatively, the ionic liquid may be

able to provide advantages in the post-processing of re-

action or extraction processes that use supercritical or

CO2-expanded liquids. The temperature, pressure, and

amount of the ionic liquid may be used to induce phase

behavior such as vapor-liquid-liquid or vapor-liquid equi-

librium. The ability to tune the phase behavior of ILs and

compressed gases to prevent IL from entering the com-

pressed gas phase yields itself for engineering applications

in refrigeration and power production. Here, the ionic liq-

uid first absorbs a gas at a relatively low temperature and

pressure, after which the solution is pumped to high pres-

sures. Lower quality (temperature) waste heat can be

used to liberate the dissolved gas producing a stream of

high-pressure-high-temperature gas. This stream may then

be used for two different types of energy applications. If

the stream is then cooled and liquefied, it may be then

sent through an expansion valve and heat exchanger to

provide a cooling effect in novel type of absorption refrig-

eration. Regardless of the application, knowledge of chem-

istry, kinetics, thermodynamics, and transport phenomena

are all required to optimize these systems.

PERSPECTIVES ON ThE USE OF SUPERCRITICAL FLUIDS IN REFRIGERATION CyCLES

79

PERSPECTIVES ON ThE USE OF SUPERCRITICAL FLUIDS IN REFRIGERATION CyCLES

gustavo BolañosSchool of Chemical Engineering,

Universidad del Valle; Cali, Colombia;


During the last years, there has been a lot of interest in

replacing the working fluids that are currently used in re-

frigeration cycles, by fluids that at the same time have low

Ozone Depletion Potential (ODP), and low Global Warming

Potential (GWP). ODP is defined as the capacity of a sub-

stance to react with the atmospheric ozone as compared

to that of trichlorofluoromethane (R11), and GWP is defined

as the global warming capability of a substance as com-

pared to that of the same amount of carbon dioxide during

a determined time span. Many of the refrigerants that are

currently in use were introduced for replacing chlorofluo-

rocarbons that were phased-out by the Montreal protocol

because of their high ODP. Unfortunately, despite their low

ODP, the replacing refrigerants have a high GWP. For ex-

ample, the ODP of R134a, a widely used refrigerant, is zero,

but its GWP is 1300.

Because reducing emissions of greenhouse gases

has been accepted worldwide as part of the effort to mit-

igate the climatic change, there is a need for new refrig-

erants with low ODP and GWP. Many synthetic refrigerants

that have been recently developed have a GWP close to

150, and only few have lower GWP. However, the manu-

facture of these compounds is difficult because they have


many isomers and thus the separation processes involved

increase the cost of such substances. In addition, in some

cases there is no knowledge on the final fate or on the mean

lifetime of these compounds once released into the envi-

ronment.

In this context, the use of carbon dioxide as a work-

ing fluid both for subcritical and transcritical refrigeration

cycles has gained a lot of attention. Historically, carbon

dioxide was in fact one of the first refrigerants that were

considered, and was used in commercial air conditioning

systems until 1932, when chlorofluorocarbons were intro-

duced. In those days, the limited technological capabilities

for handling pressures above the critical pressure of carbon

dioxide did not favor the use of this substance. Those lim-

itations do not exist today. The interest in supercritical car-

bon dioxide as a working fluid was renewed in 1990, when

several patents on transcritical cycles were awarded.

Carbon dioxide presents favorable values of ODP and

GWP (0 and 1, respectively). Its thermodynamic properties

are such that they produce a high coefficient of perfor-

mance, high compression efficiencies, and high volumet-

ric refrigeration capacities (1.6 times that of ammonia, 5

times that of R22, and up to 8 times that of R12). Its high

thermal conductivity and low viscosity, in particular in the

supercritical region, make this substance an excellent heat

transfer fluid. As a result, the size of carbon-dioxide-based

refrigeration units is smaller than those of conventional

ones, making it suitable even for mobile applications such

as automotive air conditioning. In addition, as it is well

known, carbon dioxide is not toxic, flammable or corrosive

(if no water is present). As a refrigerant, it is designated

as R744.

Several challenges have to be faced before massive

introduction of refrigeration systems based on supercriti-


cal carbon dioxide can be accomplished. Some of them

are technical, and some are non-technical. The technical

challenges are related to the need on information about

how the presence of lubricating oils that are used in in-

stallations based on the vapor compression cycle affects

the performance of the cycle. Lubricant oil is needed in the

compressor for preventing mechanical wearing of the pis-

tons and other parts, for reducing noise, and for sealing

and cooling the compressor. Phase equilibrium for mixtures

of lubricating oils and carbon dioxide is thus an important

issue that has been addressed in different publications,

as well as how the concentration of lubricant oil in the

carbon-dioxide-rich phase affects the thermodynamic and

transport properties of the fluid, and how the carbon di-

oxide dissolved in the lubricating oil affects its viscosity

and the performance of the system during its dynamic

behavior. Several works have been dedicated to measure-

ment, correlation and estimation of these properties for

engineering purposes.

Simulations considering pure carbon dioxide have

shown that there is a pressure at the exit of the compres-

sor that maximizes the coefficient of performance (COP),

and that an optimum pressure exists for a given outlet

temperature of the gas cooler. Correlations have been de-

veloped for optimum pressure, system COP and optimal

gas cooler inlet temperature. Different cycle configurations

have also been analyzed, such as the use of an internal

heat exchanger, the use of two-stage compression with

and without economizer, and the use of expanders for tak-

ing advantage of the work produced during expansion.

The objective of these studies was to find a configuration

that maximizes the cycle COP. At present, many papers

have been published on the heat transfer mechanisms and

pressure drop correlations of carbon dioxide during boiling


and cooling, in order to provide a theoretical basis for de-

signing efficient components of refrigeration cycles. In this

presentation, the main aspects of these topics will be re-

viewed.

The use of supercritical fluids as working fluids in

refrigeration cycles shows a high promise for commercial

application in a short time. Several large companies are

already committed to replacing conventional refrigeration

systems by supercritical-carbon-dioxide-based systems,

and the business opportunities in this field are growing

very fast.


SCFs as Working Fluids and Process Technology

SPECIFICS OF ThERMOPhySICAL PROPERTIES AND hEAT TRANSFER AT SUPERCRITICAL PRESSURES

85

SPECIFICS OF ThERMOPhySICAL PROPERTIES AND hEAT TRANSFER AT SUPERCRITICAL PRESSURES

igor pioroFaculty of Energy Systems and Nuclear Science,

Institute of Technology, University of Ontario;

2000 Simcoe Street North, Oshawa, Ontario L1H 7K4, Canada; E-mail: [email protected]

It is well known that the electrical-power generation is

the key factor for advances in any other industries, agri-

culture and level of living. In general, electrical energy

can be generated by non-renewable-energy sources such

as coal, natural gas, oil, and nuclear; and renewable- energy

sources such as hydro, wind, solar, biomass, geothermal

and marine. However, the main sources for electrical-energy

generation are a) thermal — primary coal and secondary

natural gas; b) “large” hydro and c) nuclear. The rest of

the energy sources might have visible impact just in some

countries. In addition, the renewable-energy sources, for

example, such as wind and solar and some others, are not

really reliable energy sources for industrial-power gener-

ation, because they depend on Mother Nature and relative

costs of electrical energy generated by these and some

other renewable-energy sources with exception of large

hydro-electric power plants can be significantly higher

than those generated by non-renewable sources.

For a sustainable and efficient power industry, ther-

mal and nuclear power plants should be used as a basis

for the electrical-energy generation, and these plants should

use high-temperature and high-pressure working fluids

including supercritical fluids. Therefore, specifics of heat


transfer and thermophysical properties of supercritical

fluids are very important for reliability and safety of new

power plants.

The use of Supercritical fluids (SCFs) in different

processes is not new, and nor was it a human invention.

Mother Nature has been processing minerals in aqueous

solutions at near or above the critical point of water for

billions of years. It was only in the late 1800’s when scien-

tists started to use this natural process, called hydrother-

mal processing, in their labs for creating various crystals.

During the last 50-60 years, this process (operating pa-

rameters - water pressures from 20 to 200 MPa and tem-

peratures from 300 to 500 ºC) has been widely used in the

industrial production of high-quality single crystals (main-

ly gem stones).

First works devoted to the problem of heat transfer

(HT) at Supercritical pressures (SCPs) started as early as

the 1930s. Schmidt et al. investigated free-convection HT

of fluids at the near-critical point with the application to

a new effective cooling system for turbine blades in jet

engines.

In the 1950s, the idea of using Supercritical water

(SCW) appeared to be rather attractive for steam genera-

tors/turbines in the thermal-power industry. The objective

was to increase the total thermal efficiency of coal-fired

power plants. At SCPs there is no liquid-vapour phase tran-

sition; therefore, there is no such phenomenon as critical

heat flux or dryout. It is only within a certain range of

parameters that deteriorated HT may occur. Therefore, the

objective of this paper is a discussion on specifics of ther-

mophysical properties and HT of SCFs in power-engineer-

ing applications.

As a result of our studies into SCFs several heat-

transfer correlations have been developed for SCW flowing

SCFs AS WORKING FLUIDS AND PROCESS TEChNOLOGy 87

upward in vertical bare tubes. The correlation based on

the bulk-fluid-temperature approach appeared to be the

most accurate one compared to other well-known 16 cor-

relations. The proposed correlation has an uncertainty of

±25% for heat-transfer-coefficient values and about ±15%

for calculated wall temperatures and is valid within the

following range: Pressures 22.8-29.4 MPa, heat fluxes

70-1250 kW/m2, mass fluxes 200-1500 kg/m2s, and tube

inside diameters 3-28 mm.

However, the developed SCW correlation has less

accuracy when applied to SC carbon-dioxide data. There-

fore, a new correlation based on the wall-temperature ap-

proach was developed. This correlation has an uncertainty

of ±30% for HTC values and about ±20% for calculated

wall temperatures and is valid within the following range:

Pressures 7.6-8.8 MPa, heat fluxes 9.3-617 kW/m2, mass

fluxes 706-3170 kg/m2s, and tube inside diameter 8 mm.

SUPERCRITICAL CARBON DIOxIDE FOR USE IN ADVANCED POwER CyCLES FOR hIGh TEMPERATURE SOLAR, NUCLEAR AND FOSSIL ENERGy

89

SUPERCRITICAL CARBON DIOxIDE FOR USE IN ADVANCED POwER CyCLES FOR hIGh TEMPERATURE SOLAR, NUCLEAR AND FOSSIL ENERGy

Mark AndersonUniversity of Wisconsin-Madison;

1500 Engineering Dr. Madison WI, 53706, USA; E-mail: [email protected]

The importance of improved efficiency, reduced capital

cost and higher operational temperature of future power

production has led to renewed interest in studying ad-

vanced Brayton cycles utilizing supercritical carbon di-

oxide as the working fluid for high temperature energy

conversion. Previous work conducted by Dostal et al. [1]

has shown that the supercritical CO2 recompression cycle

proposed by Feher [2] may be superior to other advanced

high temperature cycles both from the standpoint of in-

creased thermal efficiency as well as reduced size and

cost of the required turbo-machinery components. These

advantages make the cycle especially well-suited for any

high temperature reactor system including the Sodium-

Cooled Fast Reactor (SFR), the Fluoride Salt-Cooled High

Temperature Reactor (FHR), the Lead-Cooled Fast Reactor

(LFR) and the Very High Temperature Reactor (VHTR). The

cycle is also of interest for use in Concentrating Solar Power

(CSP) systems and has recently become of interest for use

in fossil fuel power production to aid in CO2 reduction and

sequestration. Sandia national laboratories [3] has begun

testing supercritical CO2 compressors and turbines fabri-

cated by Barber Nichols Inc. and has found promising

initial results. Argonne national laboratory has analyzed

several configurations coupled to advanced reactor de-


signs and conducted initial studies on commercial PCHEs

(Printed Channel Heat Exchangers) fabricated by Heatric.

NREL along with several commercial partners has lead

an effort to study the cycles performance for solar appli-

cations and is leading a US. Department of Energy effort

to develop a 10MW s-CO2 turbine system for demonstra-

tion and future scale up.

In order to realize these goals and demonstrate the

applicability of this cycle several key fundamental phe-

nomena need to be further understood. As an effort to

advance this technology the University of Wisconsin is

conducting research in the following different areas:

� Highly instrumented heat transfer and pressure

drop experiments on Printed circuit heat exchang-

ers (PCHE) geometries near the critical point that

can be analyzed with both 1D models and with more

complex 3D CFD models. Based on the analysis of

the experiments and the detailed CFD calculations,

improvements to the models currently used in plant

dynamics code calculations are being achieved and

optimization of heat exchanger passages for s-CO2

are being developed.

� Development and implement of optimized fluid prop-

erty algorithms within the Plant Dynamics Code

and CFD codes to increase the calculation accura-

cy and reduce computational costs. One of the ma-

jor issues with calculations of supercritical fluids is

the use of highly accurate thermal physical proper-

ty data, while this data is available through programs

such as REFPROP it is computationally expensive

to call at each itteration. Development of advanced

lookup tables using bi-cubic spline methods can

help to reduce the computational burden and still

maintain the high accuracy required in calculations.


� Experiments to investigate the critical flow of the

supercritical fluid through shaft seals and valve

components. If a fluid is near the pseudo critical

point or approaches and enters the two phase dome

the assumptions of homogenous equilibrium flow

may not hold. Research is currently underway to

determine the discharge coefficient and critical

mass flow rate for supercritical carbon dioxide at

these conditions.

� S-CO2 can be a highly oxidizing/corrosive fluid and

if it is to be used as the working fluid in power plants

with intended lifetimes of up to 40 year it is neces-

sary to investigate the corrosion mechanisms on

alloys. Corrosion coupled with the high tempera-

tures and pressures of the cycle make the selection

of appropriate materials a key area of research.

This talk will give a quick overview of some of the

above research and how it relates to the future develop-

ment of advanced s-CO2 Brayton power cycles. It will also

elucidate the interesting phenomena associated with su-

percritical fluids.

REFERENCES

[1] V. E. A. Dostal, The supercritical carbon dioxide power cycle: Compa-rision to other advanced power cycles, Nuclear Technology, 154 (2006) 23.

[2] E.G. FEHER, The Supercritical Thermodynamic Power Cycle. In: Doug-las Paper nº 4348, presented to the IECEC. August 12-17, 1967. Miami Beach, Florida, USA.

[3] S. A. Wright, P. Pickard, R. Fuller, Early supercritical CO2 compression loop operation and test results (2008).

[4] A. MOISSEYTSEV et al., Comparison of heat exchanger modeling with data from CO2-to-CO2 printed circuit heat exchanger performance tests. In: International Congress on Advances in Nuclear Power Plants 2010, ICAPP 2010, June 13-17, 2010. San Diego, CA, United States: American Nuclear Society.


[5] A. Moisseytsev and J. J. Sienicki, Development of the ANL Plant

Dynamics Code and Control Strategies for the Supercritical Carbon

Dioxide Brayton Cycle and Code Validation with Data from the Sandia

Small-Scale Supercritical Carbon Dioxide Brayton Cycle Test Loop,

ANL-ARC-218, 2011, Argonne National Laboratory.

[6] A. Moisseytsev and J. J. Sienicki, Development of a Plant Dynamics

Computer Code for Analysis of a Supercritical Carbon Dioxide Brayton

Cycle Energy Converter Coupled to a Natural Circulation Lead-Cooled

Fast Reactor, ANL-06/27, 2006, Argonne National Laboratory.

[7] G. Cao, V. Firouzdor, K. Sridharan, M. Anderson, and T.R. Allen, Corro-

sion of Alloys in High Temperature Supercritical Carbon-Dioxide, Cor-

rosion Science, 60 (2012) 246.

SUPERCRITICAL CO2 ExTRACTION OF BIOLOGICAL SUBSTRATES: FROM ThE LABORATORy TO ThE INDUSTRIAL APPLICATION

93

SUPERCRITICAL CO2 ExTRACTION OF BIOLOGICAL SUBSTRATES: FROM ThE LABORATORy TO ThE INDUSTRIAL APPLICATION

José M. del valle Departamento de Ingeniería Química y Bioprocesos,

Pontifi cia Universidad Católica de Chile; Avenida Vicuña Mackenna 4860, Macul, Santiago, Chile;


Despite extraction of valuable compounds from biological

substrates using supercritical (sc) CO2 as a replacement

of conventional organic solvent has been an industrial

reality for more than three decades, there is reluctance in

adopting this high-pressure technology because of the

wrong perception that scCO2 extraction is not fully com-

petitive. This presentation analyzes economics of scCO2

extraction of vegetable oil from prepressed seeds. This

example can be used as case study because of the avail-

ability of a mathematical model of the extraction process

that can be applied for process simulation purposes. Pre-

pressed oilseeds have an interconnected network of pores

that are filled with part of the oil expelled from fractured

cells during pressing. The shrinking core model hypothe-

sis applies to mass transfer in this substrate having as a

parameter the effective diffusivity (Ed) within the pore

network. Ed relates to a particle-size and scCO2-condition-

independent, and pretreatment dependent microstructur-

al factor. The shrinking core model is partially predictive

in that there are dimensionless correlations proposed in

literature for transport phenomena (film mass transfer, and

axial dispersion) in a packed bed operating with supercrit-

ical fluids, and for the solubility of vegetable oils in scCO2.


Estimates of extraction cost are anchored in a simulation

program describing the relationship between oil yield and

extraction time in an industrial plant having ≥3 extraction

vessels. A typical cost of about 8 USD/kg oil was estimat-

ed for scCO2 extractions at 40 ºC and 30 MPa. Optimal

mass flow rate of CO2 depends on particle diameter, which

should not be reduced necessarily below 2 mm. Extraction

cost depends little on the length-to-diameter ratio of the

vessels. For a same total volume of extraction vessels,

the cost diminished as the number of vessels increased.

For the same plant productivity, the cost diminished when

increasing extraction pressure above 30 MPa. Economies

of scales reduce cost when plant size increased. Simula-

tion results are not properly accounted for in laboratory

and pilot plan runs using a single extraction vessel.

ExTRACTION OF LIPIDS AND CAROTENOIDS FROM ALGAE By SUB- AND SUPERCRITICAL CO2 AND DIMEThyL EThER

95

ExTRACTION OF LIPIDS AND CAROTENOIDS FROM ALGAE By SUB- AND SUPERCRITICAL CO2 AND DIMEThyL EThER

Motonobu goto, hideki KandaNagoya University;

Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8603, Japan; E-mail: [email protected]

Algae of various species contain valuable organic com-

pounds. Algae are diverse group ranging from unicellular

to multicellular forms. One of these is Undaria pinnatifida,

a brown alga, commonly known as “wakame” in Japan.

This edible seaweed is widely consumed, and has been

part of the diet in many countries, especially Korea and

Japan. Algae possess several functional properties such

as antioxidant, anticancer, antiviral, and antiobesity prop-

erties. They also contain lipids and sulfated cell-wall

polysaccharides such as fucoidans. On the other hand,

microalgae are recently focused as a source of biofuel.

They also contain functional compounds. To extract the

functional compounds and lipids, organic solvent or su-

percritical carbon dioxide have been used. The extraction

process usually requires drying and grinding process. We

have applied supercritical carbon dioxide extraction for

marine algae to recover fucoxanthin and lipids [1]. Then,

we used subcritical water to recover fucoidans [2]. Lardon

et al. [3] conducted a life cycle assessment of algal bio-

diesel production, and indicated that drying and n-hexane

extraction steps consumed huge energy and made algal

fuel production in a negative energy balance. They have,

thus, suggested wet extraction as an alternative method.

Then, we proposed the use of liquefied dimethyl ether


(DME) as solvent of lipids and hydrocarbons from wet mi-

croalgae containing over 90% water content. The DME

extraction can be used for all microalgae types, e.g., Mi-

crocystis aeruginosa, Botryococcus braunii, and Euglena

gracilis.

SUBCRITICAL DME ExTRACTION

The DME extraction eliminates the need for drying,

cell disruption, and solvent evaporation at high tempera-

ture; hence, it has advantages such as simpler system and

low energy consumption. The proposed extraction uses

DME which is the simplest form of ether and has the fol-

lowing characteristics: (a) high affinity to oily compositions

and partial miscibility with water, (b) low normal boiling

point (-24.8 °C), (c) approval from the European Food Safe-

ty Authority as a safe extraction solvent for the production

of foodstuff and food ingredients, and (d) resistance to

autoxidation unlike other alkyl ethers. Because heats of

seawater (15 °C) and sun-warmed water (45 °C) around

the ambient temperature (30 °C) are converted into ener-

gy for DME extraction by DME sending pump, the total

energy required by the DME extraction is only for DME

sending pump. In other words, the DME extraction is a

novel energy-saving system [4]. Moreover, we have already

developed bench-scale equipment and verified the con-

cept of DME extraction [4,5].

ExPERIMENTAL

For supercritical CO2 extraction, semi-continuous

flow-type apparatus was used. About 5 g of dried pow-

dered sample was loaded in a 10 mL extractor vessel. Dry

sample was milled using IKA-Werke mill and then sieved

using a mesh size of 60. For subcritical water extraction,

batch reactor or semi-continuous flow-type apparatus was


used. Electric heater or microwave heating system were used

to heat-up the extractor. For subcritical DME extrac tion,

simplified flow-type apparatus was used. Wet microalgae

(water content were over 80%) were placed in the lower half

of a cylindrical extractor, while glass beads (0.71-0.99 mm

diameter) were placed at the upper half of the extractor. The

extractor was pressure-resistant glass coated with poly-

carbonate. First, liquefied DME was then supplied to the

extractor and the flow rate was adjusted by a back-pressure

regulator. At a predetermined point of temperature and

pressure, liquefied DME was passed through the extractor

at a flow rate of 10 ml/min at 20 °C [6].

RESULTS

1. Supercritical CO2 extraction

The recovered amount of fucoxanthin increased at

low temperature, and high pressure under supercritical

conditions. The maximum percent recovery reached 80%

at 40 °C and 40 MPa. The recovery of fucoxanthin is strong-

ly related to the density of supercritical carbon dioxide

which normally increases with increasing pressure and

decreasing temperature and has a positive correlation with

solvating power. It is expected that the recovery of fucox-

anthin also increased with increasing density of supercrit-

ical CO2, however, at 25 °C, low yield was obtained due

most likely to lower diffusivity of liquid CO2. It is also like-

ly that an increase in temperature above 50 °C might have

caused degradation of fucoxanthin, a thermally labile com-

pound. The use of cosolvent such as ethanol was also re-

ported to improve scCO2 extraction yield of fucoxanthin.

The drawbacks of using such cosolvent, however, include

costly and tedious separation of the solvent from the ex-

tracts and coextraction of some unwanted compounds

such as chlorophyll in the products.


2. Subcritical DME extraction

Based on extraction yields of the two solvent ex-

traction systems, the DME system was over 97.0% of the

Bligh-Dyer’s system in extraction rate, which suggests that

the yields from the two procedures, which are completely

different, was approximately the same. Also the element

compositions, molecular weight distributions, and GC-MS

spectra of extracts by both extractions are almost the same

(Kanda et al. [7,8]).

ACKNOWLEDGMENTS

A part of this research was supported by Industrial Technology Research Grant Program in 2009 (Project ID: 09B40009c, H. Kanda) from New En-ergy and Industrial Technology Development Organization (NEDO) of Japan.

REFERENCES

[1] A. T. Quitain, T. Kai, M. Sasaki, M. Goto, Supercritical Carbon Dioxide Extraction of Fucoxanthin from Undaria pinnatifida, J. Agricultural and Food Chemistry, 61 (2013a) 5792-5797.

[2] A. T. Quitain, T. Kai, M. Sasaki, M. Goto, Microwave-Hydrothermal Ex-traction and Degradation of Fucoidan from Supercritical Carbon Di-oxide Deoiled Undaria pinnatifida, Industrial & Engineering Chemistry Research, 52 (2013b) 7940-7946.

[3] L. Lardon, A. Hélias, B. Sialve, J-P. Steyer and O. Bernard, Life-cycle assessment of biodiesel production from microalgae, Environmental Science & Technology, 43 (2009) 6475-6481.

[4] H. Kanda, Super-energy-saving dewatering method for high-specific- surface-area fuels by using dimethyl ether, Adsorption Science & Tech-nology, 26(5) (2008) 345-349.

[5] H. Kanda and H. Makino, Energy-efficient coal dewatering using liq-uefied dimethyl ether, Fuel, 89 (2010) 2104-2109.

[6] H. Kanda and P. Li, Simple extraction method of green crude from natural blue-green microalgae by dimethyl ether, Fuel, 90 (2011) 1264-1266.

[7] H. Kanda, P. Li, T. Ikehara and M. Yasumoto-Hirose, Lipids extracted from several species of natural blue-green microalgae by dimethyl ether: extraction yield and properties, Fuel, 95 (2012) 88-92.

[8] H. Kanda, P. Li, T. Yoshimura and S. Okada, Wet extraction of hydrocar-bons from Botryococcus braunii by dimethyl ether as compared with dry extraction by hexane, Fuel, 105 (2013) 535-539.

MATERIALS PROCESSING By SUPERCRITICAL CARBON DIOxIDE POwDERIzATION, IMPREGNATION — AChIEVEMENTS AND ChALLENGES

99

MATERIALS PROCESSING By SUPERCRITICAL CARBON DIOxIDE POwDERIzATION, IMPREGNATION — AChIEVEMENTS AND ChALLENGES

Eckhard WeidnerRuhr University;

Universitaetsstr. 150 IB6/126, D-44780, Bochum, North-Rhine Westfalia, Germany;


The specific and unique properties of carbon dioxide are

offering new pathways to materials with new properties

by processes with considerable savings of energy and oth-

er resources.

Particle generation by supercritical technologies

was a major field of research and development in the past

three decades, resulting in hundreds of publications and

patents and some industrial applications. Processes like

CO2-assisted spray generation, spray drying, spray freez-

ing, spray agglomeration, spraying of melts, precipitation/

crystallization from supercritical solutions are well under-

stood. CO2 may act as solvent or antisolvent, lower melting

points, is reducing viscosities and/or interfacial tension,

helps mechanically to form fine dispersed sprays, acts as

blowing/cooling/freezing media, inertises and allows to

structure particles as needles, micro- or nanofoams, hol-

low spheres or even solid spheres. The particles may also

be deposited on solid substrates, forming a film. Not only

pure substances are modified with respect to particle size

and particle size distribution, but in recent years methods

to generate composites are in the focus of numerous re-

search groups. Processes and formulations for encapsulat-

ing solids, liquids or gases into so-called core-shell systems

have been developed and successfully demonstrated.


A few products have found their way into the mar-

kets. An example is micronized chocolate which, following

the PGSS-approach (Particles from Gas Saturated Solu-

tions), is produced by mixing molten chocolate with CO2

under pressure, expanding it in a nozzle to generate small

droplets, which are very rapidly crystallizing by reducing

the temperature via the co-expanding CO2. The process

allows generating specific forms of crystals (ß-V) which

together with the small size of the particles (1 to 30 µm)

results in a very unique mouth feeling. The micronized

chocolate is used to manufacture soft ice cream.

Open questions for research are how formation and

stability of dispersions (aerosols, gels, suspensions, emul-

sions, foams and so on) is influenced by supercritical fluids.

Dependencies between the properties of such dispersions

and the form, crystallinity and morphology of precipitating

solid composites have to be investigated experimentally.

Theoretical approaches for modeling phase behavior, com-

positions and transport properties of such complex systems

are required for a knowledge- and science-based approach

for designing materials, tailor-made for specific customer

demands.

A further, but less investigated process for modify-

ing materials is impregnation. Impregnation is defined as

process of imbuing or saturating with something. In tech-

nical applications impregnation is applied for modifying

properties of bulk substances by physically or chemically

binding impregnates to a bulk material or surface. Provid-

ing impregnates in liquid solutes or from a gas phase at

low to moderate pressures is state of the art, connected

with disadvantages like low space yield in case of impreg-

nation from gas phases, slow diffusion processes, long

process times and high amounts of waste water in case

of impregnation from liquid solutions. Prominent examples


demonstrate that by applying supercritical fluids and pres-

sure, impregnation time can be reduced, depths of im-

pregnation can be increased and waste water is avoided.

Between around 1990 to 2002 water-free dyeing of

textiles was intensively studied both in the US and Europe.

Although it has been proven in pilot plants that the pro-

cess is ready for commercialization, major developments

have been stopped. After some years of stagnation, Adidas

and Nike have announced in 2012 to produce T-Shirts

which are colored via CO2-dyeing in rather large industri-

al plants, operated in Thailand. It is reported that plants

with dyeing autoclaves in the m³-range are used. Future

has to show whether this is industrial breakthrough for

CO2-assisted dyeing.

A further example is impregnating wood (e.g. as

construction material for windows) with zinc-salts, making

it resistant to water and biological degradation. A large

industrial plant is operated successfully in Denmark since

about 10 years.

Impregnates might either be bound physically or

chemically on the surface or in the bulk of a substrate. In

case of physical sorption the process is mainly controlled

by diffusion and adsorption, while in the second case

chemical reaction rates have to be considered in addition.

By near-critical gas, properties of the substrate, (e.g glass

transition temperature) are modified. Gas induced swell-

ing of the substrate widen diffusion pathways and impreg-

nates dissolved in CO2 may rapidly and deeply penetrate.

Shrinkage of the substrate during expansion might pre-

cipitate and entrap impregnates physically.

Depending on the type of substrate and impregnate

chemical reactions between the two components may take

place in parallel. An example is the impregnation of leath-

er with Chromium or Alumina. Additionally to the above


described physical effects CO2 is modifying the pH-value

of the tanning solution. The chemical reaction between

chromium and proteins of the skin starts at a pH of about

2,8 and has to be increased to approx. 4 during the im-

pregnation to avoid extensive swelling and destruction of

the hide. It was demonstrated that at CO2-pressures above

3 MPa leather of excellent quality can be achieved after 2

to 3 hours, which is only 15 to 25% of the conventional

time for tanning. As the specific properties of the CO2-pro-

cess allow fine tuning of the pH-value via pressure and

assists the reaction between chromium and proteins, chro-

mium is be dosed in stoichiometric concentration. Thus

the process is free of waste water containing chromium

ions. In parallel more than 90% of the waste-water is avoid-

ed. In a pilot plant with a volume of 1,7 m³ it was demon-

strated that the process is technically and commercially

feasible. The return on investment might be as low as two

years.

Although supercritical assisted impregnation is al-

ready successfully applied in industry, the knowledge of

the underlying physical and chemical principles is limited.

Research and development is done only in a few groups

— additionally the systems are very complex. Understand-

ing the interaction of impregnates (often containing several

chemical species, additives and solvents) with supercrit-

ical fluids as well as the interaction with the substrate is

experimentally, theoretically and intellectually challeng-

ing. As multicomponent — multiphase systems are in-

volved, experiments and analytics are time consuming

and expensive. Theoretical descriptions of phase behav-

ior and transport properties are often not (yet) available.

Nevertheless industrial applications indicate that efforts

in basic research promise to be worthwhile, of high inter-

est and for sure of scientific and probably of commercial

benefit.

PANEL PRESENTATIONS

Panel I: Bio-based fuel processes

LESSONS LEARNED FROM SUPERCRITICAL wATER UPGRADING OF CRUDE OIL — APPLICATION TO BIOMASS LIqUEFACTION AND UPGRADING

105

LESSONS LEARNED FROM SUPERCRITICAL wATER UPGRADING OF CRUDE OIL — APPLICATION TO BIOMASS LIqUEFACTION AND UPGRADING

Michael T. TimkoWorcester Polytechnic Institute;

100 Institute Road, 01609, Worcester, MA, USA; E-mail: [email protected]

hydrothermal liquefaction (HTL) of biomass has many

advantages over other thermochemical biomass technol-

ogies, including superior energy efficiency (especially for

high moisture content resources) and superior bio-oil prod-

uct characteristics. Nonetheless, advances in this field

have been limited due to the challenges associated with

performing experiments and scale-up demonstrations.

Specific challenges include understanding the complex

chemistry associated with biomass feedstocks containing

carbohydrates, lignin, and potentially proteins; difficulties

pumping biomass slurries to HTL pressures at laboratory

and pilot reactor scales; corrosion and precipitation asso-

ciated with the inorganic content of biomass; difficulties

analyzing the complex heat and mass transfer dynamics

associated with HTL processes; catalyst failure due to sul-

fur or nitrogen poisoning. For these reasons, HTL has failed

to live up to its considerable commercial potential. In this

talk, I will examine parallels between HTL and a kindred

technology, supercritical water upgrading (SCWU) of crude

oil. Like HTL, SCWU seeks to use the unique physicochem-

ical properties of water near the critical point to add value

to a carbon-rich resource. Compared to biomass, crude oil

contains far fewer distinct chemical functionalities; is a

liquid at ambient conditions; contains limited inorganic


components and therefore poses reduced corrosion risk;

demonstrates partial miscibility with SCWU. My talk will

embrace the building SCWU literature, but will focus on

work performed at MIT in the past 4 years. The work at

MIT has combined experimental rate and product mea-

surements with reaction modeling and transport simula-

tion to develop an integrated understanding of the most

important physical and chemical phenomena taking place

during SCWU. The lessons learned from SCWU will then

be used to analyze future directions and opportunities for

HTL.

hIGh PRESSURE IN SyNThETIC FUEL PRODUCTION PAThWAyS

107

hIGh PRESSURE IN SyNThETIC FUEL PRODUCTION PAThWAyS

nicolaus DahmenInstitute of Catalysis Research and Technology,

Karlsruhe Institute of Technology (KIT); Hermann-von-Helmholtz-Platz 1,

76344, Karlsruhe, Baden-Württemberg, Germany;E-mail: [email protected]

high pressure is involved in various processes under de-

velopment to provide renewable energies and materials,

as e.g. in concentrated solar power and fuels as well as in

geothermal energies and carbon dioxide deep site storage.

Also, in the case of biomass utilization pressurized systems

play an important role e.g. in hydrothermal conversion of

wet or thermochemical conversion of dry materials like

e.g. pyrolysis, gasification, gas cleaning and syntheses of

chemicals and fuels. The impact and benefits taken by

application of pressure are manifold. At the example of a

process for synthetic fuels and chemicals production, so-

called second generation biofuels & chemicals, the appli-

cation of pressure in different parts of the process chain

is presented and discussed. Firstly, high pressure gasifi-

cation is introduced. Here, the aim of the elevated pressure

is to produce synthesis gas at pressures adjusted to those

required in the subsequently following chemical synthesis

process avoiding the expensive compression of syngas. In

this case the gasifier is fed with solids and liquids direct-

ly at the desired pressure. Different type of equipment and

technologies can be applied here like extrusion, dense

fluid feeding or feeding of liquids or slurries. In this case,

also gas cleaning has to be performed at the same pressure


level. To optimize the energetic efficiency, temperature also

has to be adjusted. Therefore a high temperature — high

pressure gas cleaning process is introduced including fil-

tration, sorption of sour gases and carbon dioxide as well

as catalytic decomposition of small organic and nitrogen

containing molecules, otherwise poisoning the chemical

catalysts during synthesis. For Fischer-Tropsch-synthesis

ca. 30 bar are required, for methanol or dimethylehter syn-

thesis pressures of above 60 bar and even above 100 bar.

New reactor designs and operation regimes also have been

explored, like e.g. Fischer-Tropsch synthesis carried out in

micro-structured devices at supercritical conditions. Gas-

ification of biomass usually yields a carbon monoxide to

hydrogen ratio around unity. To adjust this ratio to the spe-

cific synthesis demands, the water gas shift reaction is

also to be facilitated under elevated pressures. For all these

processes, the impact of pressure on the process funda-

mental has to be understood. For several aspects, reliable

data are already available, for others systematic investi-

gations are still required or in progress. For example, in

gasification the fluid dynamics in entrained flow reactors

or the atomization of solid and liquid fuels during injection

are most sensitive to the system pressure. Experiments,

difficult enough in pressurized reaction rooms of tempera-

tures > 1000 ºC, are supported by appropriate modeling.

Here, fluid dynamics have to be coupled with the chemical

reactions occurring in a reasonable way. For application

of elevated pressures, not only the operations conditions

have to be optimized, but also the appropriate choice of

materials, metrological devices, safety protocols has to be

considered. In some cases, pressurized processes compete

to such carried out at ambient conditions. In these cases,

assessment has to be made if the usually higher expense

for pressure vessels and equipment is balanced out by the

PANEL I: BIO-BASED FUEL PROCESSES 109

expected benefits e.g. in regard to process efficiency (ener-

gy), improved yield, or smaller reactor volumes etc. To score

the role of Supercritical Fluid Science and Technology for

new processes in biofuels, an outlook on the emerging

field of biofuels production and implementation is useful.

Biomass is the only renewable carbon resource. On a long

term, it primarily should be used for carbon based fuels

and chemicals production, while heat and electric power

can be provided by all other renewable energies. Thus,

the further exploration, research and development of bio-

mass conversion processes can be expected to attract even

rising attention offering new and exciting fields for research

and development.

BIOMASS-DERIVED SOLID FUEL AS GREEN ENERGy AND ITS SUSTAINABLE USE

111

BIOMASS-DERIVED SOLID FUEL AS GREEN ENERGy AND ITS SUSTAINABLE USE

yoshimitsu uemura, Wissam omar, noridah osman, Ahmad Rajab, suzana yusup

Universiti Teknologi PETRONAS; Bandar Seri Iskandar, 31750, Tronoh, Perak, Malaysia;


Biomass is one of the promising renewable sources. Uti-

lizing biomass may be able to mitigate the CO2 emission

and fossil fuel depletion problems. Our research group is

focusing on how to utilize lignocellulosic biomass as green

energy. In this presentation, our recent efforts on torrefac-

tion and its application will be introduced. Torrefaction is

a low temperature treatment for lignocellulosic biomass

at lower temperatures between 200 ºC and 300 ºC under

an inert atmosphere, which has been found to be effective

for improving the quality not only as a solid fuel, such as

energy density and shelf life, but also as a feedstock for

further conversion such as gasification and liquefaction.

Currently, experimental torrefaction studies are mostly on

woody and grass biomass; wood dusts, beech, eucalyptus,

willow, larch, canary grass. We are investigating if this

technology can be applicable to agricultural residues in

Malaysia. The challenge of this technology is to provide

cheap inert atmosphere. We are investigating if flue gas

from boilers can be utilized for the injection gas of torre-

faction. Possible application of the solid fuel produced by

torrefaction will also be proposed.

hIGh PRESSURE WATER REFORMING OF BIOMASS FOR ENERGy AND ChEMICALS

113

hIGh PRESSURE WATER REFORMING OF BIOMASS FOR ENERGy AND ChEMICALS

Ž. Knez, M. Škerget, E. Markočič, M. Knez Hrnčič, M. Ravber

University of Maribor; Slomškovtrg 15, SI-2000, Maribor, Slovenia;


The conversion of biomass to biofuels and biobased chem-

icals has attracted a lot of attention recently, largely due

to the environmental and socio-economic problems asso-

ciated with the use of fossil fuels. In recent time many

novel technologies have been introduced for conversion

of biomass to energy and chemicals. Hydrothermal (HT)

processes are considered as promising technologies for

the conversion of biomass into biofuels and biobased

chemicals.

BIOMASS hyDROThERMAL REFORMING

The production of biobased chemicals and energy

carriers is considered to be carbon-neutral, since the CO2

generated during processing can be absorbed by plants

during their growth. Promising technologies for the con-

version of biomass into biofuels and biobased chemicals

are hydrothermal (HT) processes, which use sub- and su-

percritical water (SubCW, SCW) as processing medium.

Generally, HT processes could be divided into four main

processes: carbonization (HTC), aqueous phase reforming

(APR), liquefaction (HTL), and gasification (HTG). In these

processes water has the role of reactant, solvent, and also

a catalyst. The main advantage over other processing


methods includes ability to use wet biomass without pri-

or dewatering and enables production of versatile chem-

icals and fuels in gaseous, liquid, or solid state. Extensive

information about the fundamentals and mechanisms of

HT reactions and state of the research is given in the lit-

erature [1]. The global increase in the production of bio-

diesel has led to a simultaneous increase in the amount

of crude glycerol, the main by-product of biodiesel plants.

The identification of high added value outlets for crude

glycerol has become an active research topic.

In the present study supercritical water reforming

(SCWR) of glycerol (10 wt% aqueous solution) was per-

formed at 673, 773 and 873 K and a pressure of 25 MPa for

various residence times. The experiments were carried

out in a high pressure continuous reactor and a compari-

son was made between non-catalyzed and catalyzed re-

actions. Cu/Zn catalyst and Cu/Zn doped with Al and Pb

were used to improve the conversion of glycerol. It was

found that Cu/Zn-Al,Pb catalyst, higher temperatures and

longer residence times favor the gasification of glycerol,

while Cu/Zn catalyst, lower temperatures and shorter res-

idence times promote dehydration over gasification.

The main gases produced during SCWR of glycerol

are H2, CO

2 and CO. The knowledge about the behaviour

of these gases in water under different conditions of tem-

perature and pressure is essential in designing the separa-

tion processes following the conversion reactions. Therefore

we have studied the solubility of H2, CO

2 and CO in water

at high temperature and pressure, and the experimental

data were correlated using various equations of state (Peng

Robinson, van de Waals). The results show that the nature

of the gas influences the behaviour of the water-gas bina-

ry system. Thus the solubility of CO2 in water increases

with increasing pressure and decreasing temperature.


Higher pressure also favors the solubility of H2, however

higher amounts of H2 dissolve in water at higher tempera-

ture. The same effect of temperature was observed for CO,

while pressure had an almost negligible effect on its sol-

ubility in water.

ChEMICALS FROM BIOMASS

Fast pyrolysis of biomass give dark brown organic

liquids, commonly termed as bio oils (pyrolysis oil), which

are chemically a complex mixture and/or emulsion of wa-

ter and degradation products of lignin (e.g. guaiacols, cat-

echols, syringols, vanillins), cellulose (such as levoglucosan,

dehydrated sugars, di-sugars, furancarboxaldehydes), and

hemicellulose (such as acetic acid, formic acid), depend-

ing on type of biomass feedstock and conditions of pyrol-

ysis process. Details on the production and the typical

properties of pyrolysis oils are presented elsewhere [2]. As

an alternative fuel, biodiesel, produced from biomass, has

been accepted throughout the world due to its several ad-

vantages. First of all, it is made from renewable sources,

which are usually vegetable oils and animal fats. Biode-

gradability, non-toxicity and low emissions in comparison

to fossil fuels are further advantages which make bio fuels

widely accepted as alternative fuels which are almost sul-

phur and nitrogen free and also carbon dioxide neutral [3].

They are considered as promising alternative fuels for

gasoline and diesel engines. For the systems pyrolysis

oil+diesel+carbon dioxide and pyrolysis oil+tail water+

carbon dioxide as well as for systems hydrogen/pyrolysis

oil and hydrogenated pyrolysis oil fundamental data were

determined [2, 3].

The study of HT reactions of cellulose, a biomass

model substance, in SubCW at temperatures 493, 523, and

573 K and autogenous pressure in batch reactor [4] showed


that the conversion to main products distributed in liquid,

gaseous and solid phase is strongly dependent on the tem-

perature and residence time. The maximal yield (51.4%)

of water-soluble products was obtained at 523 K and re-

action time of 5 min and the phase was composed mostly

of cellulose decomposition products, such as sugar mono-

mers and monomer degradation products (organic acids,

5-HMF, aldehydes etc.). Maximal yield (21.1%) of bio-oil

was obtained at 523 K and reaction time of 60 min and

consisted mainly of hydrophobic phenols and its deriva-

tives, ketones, carboxylic acids, long-chain alkanes, etc.

Gas yield was maximal (68%) at 573 K and 60 min, what

indicates that non-catalytic gasification of biomass occurs

only at temperatures above 573 K. Char formation was the

most intensive at 523 K and 60 min. The results confirm

that by targeted control of process conditions, selectivity

of reactions to desired products could be influenced.

REFERENCES

[1] I. Pavlovič, Ž. Knez, M. Škerget, Hydrothermal Reactions of Agricul-

tural and Food Processing Wastes in Sub- and Supercritical Water: A

Review of Fundamentals, Mechanisms, and State of Research, J. Ag-

ricultural and Food Chemistry, 6 (2013) 8003-8025.

[2] M. Knez Hrnčič, R. H. Venderbosch, M. Škerget, Ž. Knez, Observation

of phase behavior for bio-oil + diesel + carbon dioxide and bio-oil + tail

water + carbon dioxide system, J. Chemical and Engineering Data, 58

(2013) 648-652.

[3] M. Knez Hrnčič, R. H. Venderbosch, M. Škerget, L. Ilić, Ž. Knez, Phase

equilibrium data of hydrogen in pyrolysis oil and hydrogenated pyrol-

ysis oil at elevated pressures, J. Supercritical Fluids, 80 (2013) 86-89.

[4] I. Pavlovič, Ž. Knez, and M. Škerget, SubcriticalWater — a Perspective

Reaction Media for Biomass Processing to Chemicals: Study on Cel-

lulose Conversion as a Model for Biomass, Chemical and Biochemical

Engineering Quarterly, 7 (2013) 73-82.

SCW TEChNOLOGIES FOR BIOMASS REFINING

117

SCW TEChNOLOGIES FOR BIOMASS REFINING

Maria José coceroSchool of Industrial Engineering,

Sede Mergelina Chemical Engineering Department, Valladolid University;

47011, Valladolid, Spain; E-mail: [email protected]

The development of biobased industries, supported in the

biomass, needs a new philosophy to achieve a decentral-

ized production as an alternative to the well-supported

centralized petrochemical production plants. In order to

accomplish these challenges, research has to enable the

development of environmental compatible process, effi-

ciently handling energy and reducing the equipment costs.

These processes should be characterized by high yield and

high selectivity, simplified number of processes steps by

searching opportunities among new raw materials, and

using clean solvents as water or carbon dioxide. The re-

duction of equipment costs involves the development of

compact apparatus with reduced operation times; reduc-

ing the residence time from minutes to milliseconds allows

a reactor volume reduction from m3 to cm3. The use of

pressurized fluids has been proposed as an environmental

compatible process to integrate the depolymerization-re-

action-separation processes. Particularly, high-tempera-

ture pressurized water has proved to be a good solvent for

clean, safe and environmentally benign organic reactions

[1]. The main reasons that make the hydrothermal media

a promising alternative for biomass processing are: (a) it

is not necessary to reduce the water content in the raw


material, thus avoiding energy losses; (b) the reaction me-

dium permits the transformation of the different biomass

fractions; (c) the mass transfer limitations are reduced or

avoided, thus allowing faster reaction rates. Furthermore,

the adjustable properties of the reaction medium work as

a control factor for the reaction selectivity, avoiding the

generation of by-products. High pressurized/supercritical

water can be used for several depolymerization biomass

processes as hydrolysis, transformation in high added val-

ue compounds, gasification, fractionation and oxidation

to get energy.

CELLULOSE SCW hyDROLySIS AS PRETREATMENT

TO AChIEVE FERMENTABLE SUGARS

The hydrolysis of cellulose is completed at sub-

critical temperatures, obtaining a high concentration of

glucose and oligosaccharides, but the reaction has a low

selectivity and needs bigger reactors and higher residence

times [2]. Using subcritical water hydrolysis in the pres-

ence of a catalyst, the process can take place at a low

temperature (150 ºC), but the residence time is increased

up to 24 or 48 h [3]. The reactions of cellulose hydrolysis

under supercritical conditions are fast, but, if the reactions

are not controlled, a high quantity of derived products are

yielded [4]. The selectivity of the cellulose hydrolysis in

SCW water can be significantly improved by the reduction

of the residence time. Cantero et al [5] have found out that

the glucose selectivity obtained from cellulose was im-

proved by using ultra-fast reactions in which a selective

medium was combined with an effective residence time

control. A selective production of glucose, fructose and

cellobiose (50%) or total mono-oligo saccharides (>96%)

was obtained from the cellulose in a reaction time of

0.03 s. Total cellulose conversion was achieved with a


5-hydroxymethylfural concentration lower than 5 ppm in

a novel micro-reactor. This study shows that the hydroly-

sis of cellulose to glucose and oligomers of glucose can be

performed in residence times between 0.02-0.03 s in SCW

with high selectivity of sugars (up to 98%). The keys to

reducing the production of derived products when SCW

is the reaction medium are: (a) effective control of the res-

idence time, in order to stop the reaction after the total

hydrolysis of cellulose and before the glucose degradation

reactions; and (b) setting the conditions of the media to

favor the hydrolysis reactions and disfavor the degradation

reactions. Furthermore, the SCW glucose hydrolysis is a

high selective reaction media to achieve pyruvaldehyde

and lactic acid [6].

FRACTIONATION OF BIOMASS USING

hIGh PRESSURIzED WATER (hPW)

The fractionation of biomass to obtain high valuable

products as oils and antioxidants, hemicellulose, cellulose,

bio-oils and lining could be achieved by a HPW stepwise

process. The fractionation of grape seeds as a model bio-

mass to understand the combination of extraction and a

hydrothermal fractionation-hydrolysis process is present-

ed. The grape seeds were extracted in a first step with

ethanol/water (75%/25%) at 90 ºC obtaining ca. 13% of oil

and 0.0446 g-GAE/g-grape seeds (66% of the maximum

polyphenols), to obtain the maximum yield and antioxidant

activity. Then grape seeds were treated with high pressur-

ized water using three different temperatures: 250 ºC, 300 ºC

and 350 ºC. The solid residue varied from 0.256-0.358 g/g,

the Light Bio-oil from 0.081-0.157 g/g and High Bio-oil from

0.106-0.162 g/g. The first order kinetics for the hemicellu-

loses and celluloses in our system were k0 = 0.995 g/min

with an activation energy Ea = 13849.6 J/mol. The flow


rate increases the mass transfer in the system improving

the extraction; however, a maximum was found at a surface

velocity of 2.3 cm/min. During the hydrolysis, the pH de-

creased from 5.5 down to 3.0 due to acetyl groups libera-

tion. Finally, the carbonization of the grape seeds did not

yield to clear nanosize structures as other materials do.

REFERENCES

[1] K. Arai, R. L. Smith, T. M. Aida, J. Supercritical Fluids, 47(3) (2009)

628-636.

[2] T. Rogalinski, T. Ingram, G. Brunner, J. Supercritical Fluids, 47(1) (2008)

54-63.

[3] Z. Fang, F. Zhang, H.-Y. Zeng, F. Guo, Bioresource Technology, 102(17)

(2011) 8017-8021.

[4] M. Sasaki, K. Goto, K. Tajima, T. Adschiri, K. Arai, Green Chemistry, 4(3)

(2002) 285-287.

[5] D. Cantero, M. D. Bermejo, M. J. Cocero, Bioresource technology,

135 (2013) 697-703.

[6] D. Cantero, M. D. Bermejo, M. J. Cocero, J. Supercritical Fluids, 75

(2013) 48-57.

SUSTAINABLE TEChNOLOGIES FOR OIL-BASED SECOND GENERATION BIOREFINERIES

121

SUSTAINABLE TEChNOLOGIES FOR OIL-BASED SECOND GENERATION BIOREFINERIES

n. cotabarren, p. hegel, s. peredaPlanta Piloto de Ingeniería Química,

Universidad Nacional del Sur (PLAPIQUI-UNS-CONICET); Camino La Carrindanga Km 7 – CC 717,

8000, Bahía Blanca, Buenos Aires, Argentina;E-mail: [email protected]

A biorefinery is, by definition, the integrated production

of food, fodder, chemicals, materials, goods, and fuels by

means of bio- or physicochemical processing of biomass.

In that sense, human bodies are a good example of bio-

mass processing to recover energy and chemicals to pro-

duce materials; however, the atomic efficiency of modern

societies is quite low. Even worse, as can be seen in big

cities, the richer the population is, more residues it produc-

es. Losses in the feed chain have not yet been seriously

examined. In summary, the second-generation biorefiner-

ies not only should process non edible biomass, but also

it should push forward the gain of edible biomass resourc-

es. In that sense, new technologies for biomass recycling

and residues processing are needed to enhance the bio -

economy matrix. It is important to look at food processing

industrial centers and urban residues. For example, the

great increase of worldwide production of soybean and

sunflower oil, impacted not only in the oil market but also

in the oil refining by-products (phospholipids sludge and

distillates of the deodorizer), which prices are rapidly chang-

ing. Even though these residues contain high-added value

products, their cost are decreasing, becoming sometimes

a waste with disposal-associated problems. Furthermore,


sludge processing to recover oil or phospholipids is com-

plex. Because of its high viscosity and poor flow properties

(sticky behavior), its processing needs large volumes of

solvent, and consequently, it is expensive. An alternative

sustainable technology is the direct alcoholysis of phos-

pholipids and vegetable oil (triglycerides) occluded in the

wet gum using supercritical ethanol to produce fatty acids

ethyl esters (FAEE). Oil gums contain approximately 45%

water, 25% oil and 30% phospholipids. Therefore, the con-

ventional alkaline process is a non-viable alternative to

produce fatty esters from SOGs. By contrast, the trans-

esterification process by supercritical alcoholysis is an

interesting option for this unconventional and low-cost

feedstock [1]. On the other hand, with respect to high add-

ed value chemicals, in biodiesel processing plants acyl-

glycerols can be economically produced. Acylglycerols are

common food emulsifiers and surface active agents in many

industrial cleaning products. Commercial MG is obtained

via an alcoholysis pathway in which either fatty acids or

a fat are reacted with an excess of glycerol. The reaction

products contain mainly mono-, di-, tri-glycerides (MG,

DG, TG, respectively) and glycerol, but depending on the

glycerol/fat ratio the MG composition fluctuates between

40 and 60% of MG [2]. A further refined MG up to around

90 wt% purity, also called “high mono”, is conventionally

obtained by short path distillation of the reaction products

at ca. 473 K and 0.01 mbar or less [2]. This process is ex-

pensive and recovers only part of the produced MGs. More-

over, MG concentration higher than 96 wt% cannot be

achieved by vacuum distillation because of interesterifi-

cation reactions causes degradation of MG towards glycer-

ol and free fatty acids. Peter et al. [3] proposed an interesting

alternative to obtain 99 wt% purity of MG from the acyl-

glycerides mixture by means of supercritical fluid extrac-


tion using mixtures of carbon dioxide and propane as

extraction solvents. An alternative pathway to produce

MG, instead of transesterification, is the glycerolysis of

fatty acid methyl esters. In this case the separation prob-

lem downstream of the reactor completely changes. Puri-

fication of MG from a mixture of biodiesel can be carried

out with pure CO2 as a green solvent [4]. CO

2 presents

complete solubility with fatty esters in a wide range of

temperature and pressure, and exhibits partial miscibility

with acylglycerols (both in liquid and supercritical state).

This alternative appears as a promising process with direct

application in the biodiesel and food industry. Nowadays

strong regulations are set on oil-based biorefineries to use

nonedible vegetable oils. In that respect, the urban resid-

ual oils and fats are an interesting source of fatty acids for

biodiesel production. The commercial process to convert

used cooking oil (UCO) to used cooking oil methyl esters

(UCOME) is a pretreatment of the oil with high content of

fatty acids. The acid oil can be reacted with glycerol to

produce a mixture of acylglycerols, which are fed in a

transesterification plant, after its purification by vacuum

distillation [5]. Due to the immiscibility of the reactants,

the reaction rate is very low. In order to enhance the mis-

cibility it is carried out at temperatures above 200 ºC, but

the long residence time causes thermal degradation of the

raw materials, which end up in highly contaminating ef-

fluents. A phase equilibrium engineering of this reaction

requires thermodynamics models able to predict the mul-

tiphase behavior. GCA-EoS is a group contribution with

association model that has shown good traits to predict

phase behavior of these types of mixtures. In this presen-

tation, sustainable technologies for residues processing

and vegetable oil recycling will be discussed. Moreover,

also a high pressure technology for high purity mono-


glycerides recovery will be presented. Integration of the

discussed technologies may contribute to pave the way

towards oil-based second generation biorefinery develop-

ment. Finally, trends in the field of oil recycling and oil

based fuels other than biodiesel will be discussed.

REFERENCES

[1] G. Soto, A. Velez, P. Hegel, G. Mabe, S. Pereda, J. Supercritical Fluids,

79 (2013) 62.

[2] W. Fischer, DGF-Symposium in Germany (1998).

[3] S. Peter, B. Czech, U. Ender, E. Weidner, US Patent 5 434 280 (1995).

[4] G. SOTO, P. HEGEL, S. PEREDA, III Iberoamercian Conference on Su-

percritical Fluids, Cartagena de India, Brazil, 2013.

[5] P. Felizardo, J. Machado, D. Vergueiro, M. J. N. Correia, J. Pereira Gomes,

J. Moura Bordado, Fuel Processing Technology, 92 (2011) 1225.

BIODIESEL PURIFICATION USING SUPERCRITICAL CO2

125

BIODIESEL PURIFICATION USING SUPERCRITICAL CO2

Marcos L. corazza, papa M. ndiaye, Alexis M. EscorsinFederal University of Paraná;

Francisco H dos Santos, 100, Curitiba, PR, Brazil; E-mail: [email protected]

Currently there is great interest in developing new meth-

ods and processes focusing on biodiesel production and

purification. Regarding conventional transesterification

process for biodiesel production the use of water for bio-

diesel washing aiming the removal of glycerol, diacyl-

glycerol, monoacylglycerol, salt and other contaminants

is expensive and request a high water to biodiesel ratio

consumption. It is estimated that 3 L of water are used for

1 L of pure biodiesel produced. Thus, the development of

new processes that minimize the water consumption for

biodiesel production can be interesting from environmen-

tal and economic point of view. Due to the low solubility

of glycerol, acylglycerols (MAG, DAG and TAG) and salts

in supercritical CO2, it will be presented in this lecture

that soybean biodiesel can be efficiently separated and

purified from the reacting mixture (named crude biodies-

el) by using supercritical CO2 injection. Initially, we have

measured the phase equilibrium for the systems (m)etha-

nol(1) + glycerol(2) + CO2(3), at three different alcohol to

glycerol molar ratios (12:1, 20:1 and 30:1) and (m)ethanol(1)

+ biodiesel(2) + CO2(3), at alcohol to biodiesel molar ratio

of (3:1 and 8:1), at temperature ranged (303 K-353 K). The

high immiscibility for the systems containing the glycerol

was experimentally observed. For the systems (m)ethanol(1)


+ glycerol(2) + CO2(3) the occurrence of vapor-liquid,

liquid- liquid and vapor-liquid-liquid equilibrium were ob-

served. Regarding the biodiesel purification a given amount

of CO2 was injected using a variable-volume view cell con-

taining the mixture of crude biodiesel. The cell was then

pressurized in the range of 6-12 MPa at temperature vary-

ing from ambient (298 K) to 323 K. The amount of carbon

dioxide injected in the crude biodiesel varied from 20 wt%

to 50 wt%. Two phases were formed at the end of the pro-

cess. By mean of one-way valve, the lighter phase was

sampled and diacyglycerol, monoacylglicerol, glycerol,

biodiesel, sodium and methanol content were analyzed

using Gel Permeation Chromatography (GPC) and gas chro-

matography (GC). Results were then compared to the con-

ventional biodiesel production from a transesterification

process. The characterization was done in accordance with

the standards specification of the National Agency of Pe-

troleum, Natural Gas and Biofuels (ANP/Brazil). An exper-

imental design was performed to investigate the influence

of carbon dioxide composition, pressure and temperature.

Results obtained have showed that this process can be

able to produce a biodiesel with low levels of diacylglyc-

erol, monoacylglycerol, biodiesel (fatty acid methyl esters),

sodium, glycerol and methanol. From the results obtained

it can be seen that the temperature was the variable that

most affects the purification of biodiesel while the carbon

dioxide concentration and the pressure has a minor effect.

The best condition was obtained at low temperature. In a

general way, in this proposed process the obtained bio-

diesel presented lower levels of sodium, glycerol and meth-

anol contents than the values specified by the National

Agency of Petroleum, Natural Gas and Biofuels (ANP/

Brazil). This process represents a promising technique in

further biodiesel downstream purification steps.

CRITICAL FLUIDS APPLICATION FOR EFFICIENT PROCESSING OF LIGNOCELLULOSE BIOMASS AS PART OF AN INTEGRATED BIOREFINERy

127

CRITICAL FLUIDS APPLICATION FOR EFFICIENT PROCESSING OF LIGNOCELLULOSE BIOMASS AS PART OF AN INTEGRATED BIOREFINERy

Regina c. D. santosUniversity of Birmingham;

Edgbaston, B15 2TT, Birmingham, West Midlands, UK; E-mail: [email protected]

It is widely acknowledged that lignocellulose biomass

derived from forestry, energy crops, agricultural and food

processing residues represents a significant renewable

resource that has yet to be exploited to its full potential.

Fermentation, either liquid or solid state are accepted routes

by which it is thought lignocellulose biomass can be up-

graded to liquid and gaseous bioenergy carriers and even-

tually platform chemicals, reducing our current dependence

on fossil fuels. However, the recalcitrant nature of ligno-

cellulose reduces fermentation efficiency. Attempts to

overcome the resistant structure of the biomass have led

to extensive research in the area of ‘pre-treatment’. To

date there are a large number of reports describing the

application of acid, alkali, and other solvents, combined

with a range of physical treatments. However most if not

all, while breaking down the physical barrier, often induce

the production of either naturally occurring or novel chem-

ical intermediates that conspire to again reduce fermen-

tation efficiency. The work currently being undertaken

at the University of Birmingham, School of Chemical En-

gineering will be presented, where researchers are eval-

uating and developing strategies to optimise biomass

pre-treatment and therefore maximise the potential of

lignocellulose utilisation in downstream fermentation.

PANEL PRESENTATIONS

Panel II: New Materials and Materials Processing

SyNThESIS OF METALLIC NANOPARTICLES USING SUPERCRITICAL FLUIDS

131

SyNThESIS OF METALLIC NANOPARTICLES USING SUPERCRITICAL FLUIDS

M. crone, s. Müller, M. TürkDepartment of Chemical and Process Engineering,

Karlsruhe Institute of Technology (KIT); Engler-Bunte-Ring 21, 76131, Karlsruhe, Baden-Württemberg, Germany;


In the 21st century, manufacturing as well as service in-

dustries must increasingly attempt to avoid production,

use, and release of harmful substances into our environ-

ment. Furthermore, discovering environment-friendly and

renewable energy sources is one of the major challenges

in the present and future. As a result of these two factors

new processes must be therefore environmentally friend-

ly when employed at a large scale. During the last thirty

years numerous technological advances indicate that the

use of supercritical fluids (SCFs) enables the overcoming

of these environmental problems and offers new and prom-

ising pathways for material processing. SCFs are charac-

terized by densities very close to those of liquids and mass

transfer properties lying between those of gases and liq-

uids. Depending upon the fluid density, the fluid may be

tuned to behave as a specific solvent for a specific sub-

stance at one pressure, but as a non-solvent at another

pressure. SCF-based processes are characterized as envi-

ronment-friendly due to the low-energy solvent and prod-

uct recovery. In addition a solvent-free product can be

obtained in a single processing step by partial system

depressurization. These specific characteristics of SCFs

can be exploited to design and synthesize new materials


— in particular nanoparticles — for advanced performance

in numerous applications. Nanoparticles, i.e. particles

which have at least one dimension on the nanometer scale

(1 to 100 nm) have become more and more important in a

large number of technological important areas such as

chemistry, energy, electronics, optics and pharmacology.

Noble metal nanoparticles and, in particular, platinum (Pt)

nanoparticles have demonstrated to be efficient catalysts

for chemical reactions such as hydrogenation, hydration

and oxidation [1]. They are often prepared by aqueous

impregnation of a porous support with a metal-containing

solution, followed by reductive treatment. Catalysts pre-

pared by this procedure yield to metal particles with broad

size distribution and to large volumes of waste water. A

promising environment-friendly alternative to this con-

ventional preparation route is the application of SCFs to

achieve high dispersions of noble nanoparticles on po-

rous supports (e.g. TiO2, Al

2O

3, Black Pearls, Carbon nano-

tubes) [2]. Material design using methods involving SCFs

is achieved through two distinct processes. Particle forma-

tion can thus be based on either a physical transformation

(e.g. rapid decompression, anti-solvent effect.) or a chem-

ical reaction. In case of the second method, metallic nano-

particles can directly be deposited on various solid supports

by Supercritical Fluid Reactive Deposition (SFRD) [3]. In

this process, the SCF acts as a solvent, reaction and sep-

aration media. The SFRD technique involves the dissolu-

tion of the organometallic precursor in a SCF (e.g. scCO2)

and the exposure of a support to the solution. After suffi-

cient time for impregnation, the precursor will be trans-

formed to its metal form with a reducing agent, such as

hydrogen. Different methods can be used to convert the

organometallic precursor to its metal form: a) chemical

reduction in scCO2 with hydrogen, b) chemical reduction

PANEL II: NEW MATERIALS AND MATERIALS PROCESSING 133

at atmospheric pressure with hydrogen, c) thermal reduc-

tion in scCO2, and d) thermal reduction at atmospheric

pressure in an inert atmosphere. Usually method b) was

only used on selected samples for comparison while meth-

od a) was the preferred process. At the end of these ex-

periments, the system is slowly depressurized and cooled

down to ambient conditions. Since both, CO2 and the re-

action products are in the gaseous state, phase separation

can be easily realized and a solvent free product is ob-

tained. Thus, the SFRD technique represents an integrat-

ed process that enables process intensification because

it combines several steps of the conventional process. In

our investigation, the influence of different organometal-

lic precursors, various supports and reduction conditions

on particle size, size distribution, and metal loading was

investigated. The product was characterized by scanning

and (high resolution) transmission electron microscopy

(SEM and HRTEM), energy-dispersive X-ray spectroscopy

(EDXS), powder X-ray diffraction (XRD), and ICP-OES anal-

yses. First, this talk will give an introduction into the ba-

sics of the SFRD process, including a short discussion of

the solubility and the phase behaviour of the precursor in

the SCF as well as of the adsorption behaviour of the pre-

cursor on the support. Based on this, typical results ob-

tained from SFRD experiments are presented and discussed.

In summary, the results of our investigations show that:

1) The average particle size and size distribution can

be affected by type and amount of the precursor in

the system, precursor reduction method and con-

dition, surface properties (surface area and chem-

ical nature) of the support [3].

2) The SFRD process enables the formation of uniform

Pt, Pd, Au, Ag- and bimetallic (Au-Ag) nanoparticles.


3) Adsorption behaviour determines the metal amount

which can be deposited on the support.

4) Pt- and Pt/Cu-catalysts prepared by SFRD exhibit-

ed an activity higher than reference samples pre-

pared by conventional wet impregnation [4,5].

At the end of the talk the main conclusions and

further perspectives are summarized and discussed.

REFERENCES

[1] C. J. Zhong, M. M. Maye, J. Luo, L. Han, N. Kariuki, Nanoparticles in

catalysis, in: V. Rotello (Ed.) Nanoparticles: building blocks for nano-

technology. Kluwer Academics, Plenum Publishers; NY, 2004, 113.

[2] C. Erkey, J. Supercritical Fluids, 47 (2009) 517.

[3] V. Aggarwal, L. Reichenbach, M. Enders, Th. Muller, S. Wolff, M. Crone,

M. Türk, S. Bräse, Chemistry European J., 19 (2013) 12794.

[4] G. Incera Garrido, F. C. Patcas, G. Upper, M. Türk, S. Yilmaz, B. Kraushaar-

Czarnetzki, Applied Catalysis A: General, 338 (2008) 58.

[5] S. Lang, M. Türk, B. Kraushaar-Czarnetzki, J. Catalysis, 286 (2012) 78.

SUPERCRITICAL CARBON DIOxIDE DRyING OF SILICA ALCOGEL: STATE-OF-ThE-ART AND OUTSTANDING NEEDS

135

SUPERCRITICAL CARBON DIOxIDE DRyING OF SILICA ALCOGEL: STATE-OF-ThE-ART AND OUTSTANDING NEEDS

Marc hodesMechanical Engineering Department,

Tufts University; 200 College Ave., Medford, MA, 02155, USA;


Aerogels are dry, nanoporous, nanostructured materials

with unique and extreme properties including ultra-low

density and thermal conductivity. To date the commercial

focus of aerogels has been superinsulation. Indeed, heat-

ing and cooling of buildings in the United States, e.g.,

accounts for 15% of energy consumption and 32% of CO2

emissions and the superinsulating properties of commer-

cially-available aerogel blankets can immediately and

substantially reduce these numbers. Unfortunately, aero-

gel superinsulation is 10 times more expensive than con-

ventional insulation; say, polyurethane. Hence, while the

worldwide insulation market is about $40 billion, aerogels

account for less than 1% of it and it is projected that the

aerogel industry will grow to only $330 million by 2017.

The two common techniques for removing the alcohol from

the pores of a silica alcogel and replacing it with air there-

by affording an aerogel are ambient pressure drying and

supercritical carbon dioxide (scCO2) drying, the focus here.

scCO2 drying enables extraction of solvent from a gel while

preserving the delicate nanostructure of its solid skeleton

by eliminating phase boundaries and thus capillary forc-

es. Beneficially and unlike direct supercritical extraction,

scCO2 drying is a low temperature and nonflammable pro-


cess. However, scCO2 drying requires substantial infra-

structure, i.e., expensive pressure vessels, fluid handling

equipment, and process control hardware, and copious

amounts of CO2. Moreover, scCO

2 drying and CO

2 recycling

are cost- and energy-intensive and, importantly, drying is

the rate-limiting step in the manufacture of aerogels.

We discuss the state-of-the-art in scCO2 drying of

alcogels with a focus on the drying kinetics study recent-

ly completed at Tufts University. In this study we dried 5,

10 and 15 mm-thick x 56 mm OD x 220 mm-tall annuli of

alcogel that were concentric with a 56 mm ID x 76 mm

OD annular gap through which scCO2 flowed. This was

accomplished over a range of CO2 mass flow rates (1 kg/

hour to 5 kg/hour), operating pressures (100 bar to 138 bar),

and operating temperatures (50 oC to 70 oC) using two

different solvents, i.e., ethanol and methanol. Alcohol ex-

traction rates were continuously measured for the first time.

The total mass flow rate of scCO2 plus alcohol leaving the

reactor was measured using a Coriolis flow meter. Down-

stream of this flow meter, the effluent flowed through a

series of heated decompression valves and separated into

liquid and vapor streams. The mass flow rate of liquid

alcohol was measured using a collection beaker and bal-

ance. The mass flow rate of alcohol in the vapor stream

was computed from measurements of the mass fraction

of alcohol in it using an infrared hydrocarbon sensor and

extraction rate versus time then computed. Comparison

between theory and data showed mass transfer to be a

diffusion-limited process, except at sufficiently low scCO2

mass flow rates, where the mass transfer driving force was

depleted due to the buildup of ethanol in the scCO2 stream

flowing over the alcogel. It was necessary to utilize a con-

centration-dependent molecular diffusivity to properly pre-

dict drying kinetics.


Our presentation concludes with a discussion of

outstanding needs which must be addressed to accelerate

and reduce the cost of scCO2 drying. These include the

development of experimentally-validated equations of state

to compute the density of ethanol-CO2 and methanol-CO

2

mixtures at process conditions. Once such data are avail-

able, installing a Coriolis flow meter in the effluent stream

enables pressure, temperature and density to be simulta-

neously measured and, importantly, mass fraction of al-

cohol in the effluent to be computed. Then, the mass flow

rate of alcohol leaving the extractor vessel equals solute

mass fraction times effluent mass flow rate, and integrat-

ing this quantity over time enables the fraction of the total

alcohol initially in the extractor to be monitored. A second

outstanding need is measurement of concentration-de-

pendent molecular diffusion coefficients in relevant systems

at process conditions. It is suggested that the laser-induced

grating method be used for this purpose because it is

non-intrusive, has been successfully utilized to measure

(Soret, thermal and mass) diffusion coefficients in super-

critical water and, finally, unlike more common techniques

such as those based on Taylor dispersion, it applies across

the full range of solute concentrations. Finally, elucidation

of the effects of “suction” and “swelling” in alcogels during

drying due to the non-monotonic dependence of density

on solute concentration need be resolved.

BEyOND ThE BARRIER IN GAS FOAMING: hOLLOW POLyMERIC MICRO- AND NANOPARTICLES

139

BEyOND ThE BARRIER IN GAS FOAMING: hOLLOW POLyMERIC MICRO- AND NANOPARTICLES

s. orsi, E. Di Maio, p. A. netti, s. iannaceDepartment of Chemical, Materials and production Engineering,

University of Naples; P.le Tecchio 80, 80125, Naples, Italy;


hollow polymeric nanostructures have huge scientific and

industrial value. In particular, they are used for encapsu-

lation of drugs, enzymes, proteins and genes in biomedi-

cal and pharmaceutical applications, for contrast agents

for diagnostic as nanoreactors in chemistry and chemical

engineering, as transducers and dielectrics in electronics.

The current methods for the preparation of hollow poly-

meric nanostructures include: emulsion polymerization,

suspension poly-merization, core-shell precursors, self-as-

sembly, electrospraying and template-directed synthesis.

The aim of this work is to introduce gas foaming as a suit-

able technology to produce hollows in micro- and nano-met-

ric polymeric particles. Gas foaming is a common technique

to generate hollows in bulk polymeric materials. Gas es-

cape from super-saturated polymer/blowing agent solution

is the driving force to bubble nucleation and growth. How-

ever, gas escape also determines a gas loss through the

external free surface, in particular in the 10-100 microns-

thick layer of the polymeric matrix in contact with the ex-

ternal surface. This phenomenon essentially impedes the

use of the gas foaming technology to produce hollow mi-

cro- and nano-metric particle, since the whole volume,

essentially, is so close to the external surface that the dif-


fusive path available to the gas within the induction time

required for foaming. The proposed approach consists of

retarding the gas loss from the free surface by embedding

the particles in a removable barrier film. In doing so, we

introduce an obstacle to mass transport that hinders gas

loss from the free surface, at least within the time required

for bubble nucleation, thereby allowing the phase sepa-

ration within the particle. Barrier film-embedded polysty-

rene spheres were prepared by dispersing polystyrene

spherical particles (500-50-5-0.5-0.2 µm in diameter) (Duke

Scientific) dispersed in aqueous solutions poly(vinyl alco-

hol) (PVA) (Mowiol 40-88, Sigma-Aldrich, dried at room

temperature for 72 h). Bare polystyrene spheres (without

the barrier film) were also analysed and subjected to the

following foaming process. For the production of foamed

samples, a thermo regulated and pressurized cylinder hav-

ing a volume of 0.3 L, (model BC-1, HiP Erie, US-PA) was

used. The pressure discharge system consists of a dis-

charge valve (model 15-71 NFB, HiP Erie, US-PA), an elec-

tromechanical actuator (model 15-72 NFB TSR8, HiP Erie,

US-PA) and an electro-valve. The pressure history was reg-

istered by using a data acquisition system (DAQ PCI6036E,

National Instruments, US-TX) and a pressure transducer

(model P943, Schaevitz-Measurement Specialties, Hamp-

ton, US-VA). In a typical experiment, the samples (barrier

film-embedded polystyrene spheres and bare polystyrene

spheres) were loaded into the vessel, pressurized with the

blowing agent at 14 MPa and 100 °C for two hours and

pressure quenched at 100 MPa/s. Particles were recovered

by dissolving the PVA films in water at room temperature

and washed centrifuging with water five times. To verify

particle morphology, Focused Ion Beam-Scanning Electron

Microscopy, Transmission Electron Microscopy and Con-

focal Microscopy were used. Results show hollow particles


achieved with the use of a barrier film embedding the par-

ticles with diameters ranging from 50 microns to 200 nano-

meters. The three order of magnitude spam in the particles

dimension is an evidence of the high versatility of the pro-

posed methodology. It is worth of note, furthermore, that

PS bare particles (not embedded in PVA and collected on

a permeable substrate) did not present any hollow, at all

scales and experimental conditions. Finally, the proposed

methodology has a high efficiency in terms of number of

affected particles versus total number of particles. Among

the many peculiar characteristics of the proposed meth-

odology, it is simple, economic, environmentally friendly,

robust, controllable and does not need any fine chemistry

in polymer synthesis, emulsion or suspension preparation.

Furthermore, it is suitable for a wide range of particle di-

mensions and shapes and allows achieving a large variety

of possible pore structures. As a counterpart, however, the

proposed methodology allows for a reduced control of the

pore morphology and a subsequent sorting of particles

could be necessary for specific applications.

PERSPECTIVES ON ThE USE OF COMPRESSIBLE FLUIDS IN ThE PREPARATION AND PROCESSING OF POLyMER SySTEMS FOR DRUG DELIVERy APPLICATIONS

143

PERSPECTIVES ON ThE USE OF COMPRESSIBLE FLUIDS IN ThE PREPARATION AND PROCESSING OF POLyMER SySTEMS FOR DRUG DELIVERy APPLICATIONS

sandro R. p. da RochaWayne State University;

5050 Anthony Wayne Dr, 48085, Detroit, MI, USA; E-mail: [email protected]

Polymers find a wide range of potential applications in

the biomedical industry, including as drug depots and

carriers that may afford (a) protection to sensitive cargo,

and strategies for the (b) controlled release and (c) target-

ing of therapeutic molecules to desired tissues, so as to

enhance their efficacy and safety profiles. Supercritical or

(more generally speaking) compressible fluid (SCF)-based

technologies offer unique opportunities in terms of both

polymer preparation and their processing with therapeu-

tics for drug delivery applications.

Supercritical CO2 (scCO

2) is of especial relevance

as a polymer reaction and processing medium for drug

delivery applications as it is non-toxic, non-flammable,

relatively inert, and it can be sourced with high purity.

scCO2 also has excellent mass and heat-transfer proper-

ties, and low surface energy. Moreover, the separation of

scCO2 from the polymer product or drug-polymer system

is facilitated as scCO2 can be reverted to the gaseous state

by simple depressurization, thus eliminating energy inten-

sive solvent removal steps that exist in processes involving

conventional solvents. However, there are many challenges

in using scCO2 for polymer preparation and processing with

therapeutics, perhaps one of the most notable being the

fact that while most monomers are soluble in scCO2, most


polymers (and many small molecular weight therapeutics

for that matter) are not.

The good news is that the very same characteristics

that challenge the use of scCO2 in polymer synthesis and

polymer-drug processing, such as its poor solvent power,

can actually be turned around and used as unique oppor-

tunities to develop groundbreaking technologies, both in

terms of reaction medium and in the development of de-

pots for drug delivery applications.

For example, the fact that most polymers are insol-

uble in scCO2 is what makes scCO

2 an excellent candidate

medium for the development of innovative dispersion-

based polymerization strategies. While most polymers are

not soluble in scCO2, they can be plasticized by scCO

2.

This characteristic, along with its low viscosity and high

diffusivity, points to scCO2 not only as a good solvent can-

didate, but as a unique solvent environment in dispersion

polymerization. For example, scCO2 has been reported as

a reaction medium that facilitates the access of growing

chain ends and RAFT polymerization agents to monomers

arriving into the growing latex, thus leading to a more

efficient polymerization strategy [1].

Another interesting example of turning things/per-

ceived disadvantages of scCO2 around comes from the fact

that scCO2 is poorly miscible with water, and miscibility

gaps can be found with organic solvents. These charac-

teristics may provide opportunities for the development of

novel emulsion-type polymerization and co-polymerization

strategies, strategies which have been scantly explored.

New opportunities in this area may also arise due to recent

advancements in surfactant design for those interfaces,

and better understanding of microemulsion formation in

scCO2-based systems.

Yet another example of potential contributions of

scCO2-based technologies is in the preparation of polymer


drug depots. While most polymers have low solubility in

scCO2, scCO

2 itself can be used to plasticize polymer ma-

trices for enhanced blending of other polymers [2] or im-

pregnation with therapeutic molecules [3]. scCO2 can also

be used to prepare polymer micro- and nanoparticles, and

polymer fibers [4] with encapsulated drug solutes. scCO2

in this case may offer great advantages compared to tra-

ditional methods where the drug molecules may be water,

organic solvent or heat labile, as for example protein ther-

apeutics.

In spite of the potential advantages of scCO2 in the

synthesis of polymeric materials and their processing for

drug delivery applications, commercial processes involv-

ing such systems are very limited. The ability to promote

the future utilization of scCO2-based technologies in this

area hinges on our ability to continue to develop process-

es where scCO2 is not only a good alternative solvent, but

the superior choice or the unique route for product devel-

opment, along with stricter environmental laws, so as to

tip the balance towards cleaner technologies.

REFERENCES

[1] J. Jennings, M. Beija, A.P. Richez, S.D. Cooper, P. E. Mignot, K. J.

Thurecht et al., One-Pot Synthesis of Block Copolymers in Supercritical

Carbon Dioxide: A Simple Versatile Route to Nanostructured Micro-

particles, J. American Chemical Society, 134 (2012) 4772-81.

[2] C. A. Kelly, A. Naylor, L. Illum, K. M. Shakesheff, S. M. Howdle, Su-

percritical CO2: A Clean and Low Temperature Approach to Blending

PDLLA and PEG, Advanced Functional Materials, 22 (2012) 1684-91.

[3] C. Gonzalez-Chomon, M. E. M. Braga, H. C. de Sousa, A. Concheiro,

C. Alvarez-Lorenzo, Antifouling foldable acrylic IOLs loaded with nor-

floxacin by aqueous soaking and by supercritical carbon dioxide tech-

nology, European J. Pharmaceutics and Biopharmaceutics, 82 (2012)

383-91.

[4] L. Li, Z. Jiang, Q. Pan, T. Fang, Producing Polymer Fibers by Electro-

spinning in Supercritical Fluids, J. Chem-Ny. (2013).

NANOSTRUCTURATION OF POLyMER MATRICES By ExTRUSION ASSISTED WITh A SUPERCRITICAL FLUID

147

NANOSTRUCTURATION OF POLyMER MATRICES By ExTRUSION ASSISTED WITh A SUPERCRITICAL FLUID

Jacques fages, Elisabeth Rodier, Martial sauceau, nibal hijazi, nicolas Le Moigne, Jean-charles Benezet,

Tamás vigh, Zsombor nagy, gyorgy MarosiÉcole des Mines – CNRS – RAPSODEE research centre;

Campus Jarlard, 81013, Albi, France; E-mail: [email protected]

In an eco-design and sustainable development perspec-

tive, many research works have recently been devoted to

bio-sourced polymers. Manufacturing nano-composite with

a polymeric matrix incorporating either an active pharma-

ceutical ingredient or a bio-filler may enlarge the field of

applications of such structures towards several industrial

areas: pharmaceuticals, detergents, fine chemicals, etc.

In this lecture a few examples of nano-composite manu-

facturing process will be presented based on a supercritical

carbon dioxide-aided extrusion process (acronym: XSCF).

Pharmaceutical extrusion also known as HME (hot melt

extrusion) is an efficient technology used to disperse drugs

in a melt up to a true molecular solution of a pharmaceuti-

cal ingredient. Most of the applications describe the prepa-

ration of solid dispersions by HME either to increase the

aqueous solubility and oral bioavailability of the active

substance or to control its release. The mostly reported

advantages of HME are: (a) avoidance of organic solvent;

(b) reduction of processing steps (one-pot method); (c)

elimination of the good compressibility requirement for

the active ingredients and the excipients; (d) high level of

drug content; (e) even dispersion of the drug throughout

the matrix; and (f) improved bioavailability through drug


solubilisation or molecular level dispersion in water solu-

ble matrix. The injection of scCO2 in the extrusion process

modifies the rheological properties of the polymer, and also,

scCO2 acts as a blowing agent at the die exit. In the bar-

rel of the extruder, the reduction of viscosity decreases the

mechanical constraints and the operating temperature.

At the die exit, the pressure drop induces a thermodynam-

ic instability in the polymer matrix, generating a large

number of bubbles, which can grow until the foam is ri-

gidified when temperature drops below the glass transi-

tion temperature, Tg. The influence of several operating

parameters, die geometry and temperature, polymer crys-

tallinity, upstream pressure, addition of nanoparticles will

be discussed. It could be concluded that the combination

of extrusion with scCO2 allows processing relatively frag-

ile or thermally sensitive molecules, like pharmaceutical

molecules, without any residue in the final material. A few

examples of XSCF implementation leading to significant

improvements in drug dissolution kinetics will be pre-

sented. Extrusion is a widely used process to prepare

nanocomposites with silicate-layered materials. Both melt

intercalation and exfoliation can be obtained by XSCF. An

example with PHB-HV and Cloisite, a natural montmoril-

lonite clay, will be given. A new approach can be to gen-

erate nanoparticles from a biobased polymer to be used

as a filler in a matrix. In our laboratory, we have been

working with chitosan, a polysaccharide derived from shell-

fish and some fungi. It has several properties including

biodegradability, antibacterial and antifungal activities,

making it a material of choice for applications in packag-

ing and medical field. Particles were generated by a clas-

sic SAS process (Supercritical Anti-Solvent), minimizing

the use of organic solvents. scCO2 acts as an anti-solvent

while chitosan is dissolved firstly in an acidic aqueous


solution to which ethanol has been added to improve the

anti-solvent effect of the sc-CO2. Two coaxial capillaries

allow the injection of the chitosan solution (the inner one)

and CO2-sc (the outer one) in an autoclave filled with CO

2

in which the particles are generated at 18 MPa and 306

K. The miscibility of the CO2 with ethanol and acetic acid,

the solvent of chitosan, induces the reduction of the sol-

vating power of the latter, which causes the crystallization

of the particles. The sc-CO2 loaded with solvents is sent

to three separators where gradual depressurization will

separate the solvents and purify the CO2, that returns af-

terwards to the autoclave. Using this process, we gener-

ated chitosan nanoparticles with an average size of 378

± 13 nm and a positive mean zeta potential of 26.4 ± 0.2

mV. We have also developed a more innovative process,

which led to nanoparticles of chitosan without any organ-

ic solvent. A further step, under present investigation, is

to disperse these nanoparticles by extrusion in a biopoly-

mer matrix, to produce a composite material for biomed-

ical application.

REFERENCE

f M. Sauceau, J. Fages, A. Common, C. Nikitine, E. Rodier, New chal-

lenges in polymer foaming: a review of extrusion processes assisted

by supercritical carbon dioxide, Progress in Polymer Science, 36 (2011)

749-766.

OPPORTUNITIES IN FABRICATION OF hIGh POROSITy NANOFIBROUS STRUCTURES

151

OPPORTUNITIES IN FABRICATION OF hIGh POROSITy NANOFIBROUS STRUCTURES

carson MeredithSchool of Chemical & Biomolecular Engineering,

Georgia Institute of Technology; 311 Ferst Dr., 30332-0100, Atlanta, GA, USA;


Nanofibrous structures with high surface area are appeal-

ing to a wide range of practical applications in energy-re-

lated fields. These include white reflective surfaces for

energy-efficient roofing, insulation, catalyst supports, sen-

sors, filtration media and absorbents, lightweight structur-

al materials and energy storage devices (supercapacitors

and batteries). Current synthetic processes for fabricating

low-defect, large-area nanofibrous structures with control-

lable fiber diameter, interconnectivity, and porosity suffer

from a number of drawbacks. These include use of volatile

organic solvents and scalability issues. Nature also pro-

duces intricate nanofibrous structures at ambient condi-

tions, such as the dense high-strength Bouligand structure

of lobster shells (composed of chitin and mineral) and wood

(composed of cellulose) or the lightweight ultrathin cuticle

of the Cyphochilus beetle. This cuticle contains a three-di-

mensional aperiodic network structure composed of chitin

fibrils around 250 nm in diameter and containing about

30% air void volume, which results in both light weight

and significant whiteness and reflectivity. The first part of

this talk will review recent work in controlling the freeze-

drying (sublimation) process to achieve fine, nanofibrous

structures that mimic those produced in nature. The sec-


ond part of this talk will take a forward-looking view of

opportunities to utilize a relatively well-established tech-

nique, supercritical drying, to produce high porosity nano-

fibrous structures from a wide range of materials. Freeze

drying has attracted intense interest as a general route to

fabricate porous materials for a wide range of applications.

Starting with a solution, emulsion, or dispersion, freezing

causes solute or solids to be excluded by an advancing

ice front into the interstitial spaces between ice crystals.

Subsequent sublimation leads to porous structures. By

controlling concentration and freezing direction, complex

hierarchical morphologies are produced, including well-

aligned channels, honeycombs, and brick-mortar-bridges

(sheet-like structures that are oriented). Because of the

large temperature gradients in common liquid-N2-based

freeze drying, most studies report oriented structures re-

sulting from fast, directional freezing. In contrast, non-di-

rectional freezing and solidification under higher freezing

temperatures, required to produce elongated fiber struc-

tures, are not well explored. For example, structures that

mimic the size and interconnectivity of the white beetle

cuticle have not been achieved by freeze drying previous-

ly. To reproduce the aperiodic nanofiber structure, we show

that freezing under higher temperature conditions (-20 °C)

reduces the temperature gradient and allows non-direc-

tional freezing. Furthermore, because chitin dispersions

readily form gels and liquid crystalline phases, we show

that slowing the ice growth velocity allows encapsulation

and preservation of networks of chitin fibers whose inter-

connectivity depend on the dispersion conditions just pri-

or to freezing. Precursor solutions or dispersions of fibers

can also be fabricated into controlled nanoarchitectures

by self-assembly or electrospinning processes, but the sol-

vent must then be removed while preserving the architec-


ture. There are drawbacks in terms of scalability and the

use of volatile organic solvents, especially in spinning pro-

cesses. Because of surface tension and interparticle at-

traction, there is potential for contraction or even collapse

of self-assembled structures during the drying step. The

second part of this talk will survey opportunities to couple

supercritical drying with existing self-assembly and spin-

ning approaches to produce high porosity nanofibrous

structures from a wide range of materials. Strengths and

weaknesses, as well as obstacles to be overcome, will be

discussed. Connections of structures to applications of

relevance to energy savings, energy production and ener-

gy storage are drawn.

MORPhOLOGy DEVELOPMENT AND PORE FORMATION IN SEMI-CRySTALLINE POLyMERS DURING CRySTALLIzATION IN CO2

155

MORPhOLOGy DEVELOPMENT AND PORE FORMATION IN SEMI-CRySTALLINE POLyMERS DURING CRySTALLIzATION IN CO2

Erdogan KiranDepartment of Chemical Engineering;

Virginia Tech, USA;

shinya TakahashiKureha Corporation, Japan

Compressed or supercritical fluids such as carbon dioxide

is of continuing interest and importance in various polymer

modifications ranging from forming particles and fibers

to foams and porous matrices. Even though polymers are

typically not soluble in carbon dioxide, carbon dioxide can

dissolve in a polymer, leading to enhanced chain mobility.

The immediate consequence of increased chain mobili-

ty is the lowering of the glass transition temperature (Tg)

and the delaying of the vitrification process, which by itself

widens the temperature range in which modifications can

be carried out. The lowering of the glass transition tempera-

ture is well documented for amorphous polymers. When

semi-crystalline polymers are involved, with dissolution of

carbon dioxide in the polymer matrix, if the melting tem-

perature (Tm) is not crossed, increased chain mobility leads

to lamellar thickening and to a recrystallized polymer which

displays a higher melting temperature and higher level of

crystallinity. This is also well documented in the literature.

If however, a semi-crystalline polymer is exposed to carbon

dioxide at temperatures where the polymer is in its molten

state, and then its recrystallization is carried out by low-

ering the temperature in the presence of carbon dioxide,

one observes lower crystallization temperatures compared


to the ambient pressure crystallization temperature from

the melt in the absence of carbon dioxide. Lowering of Tm

is also a consequence of increased chain mobility and is

well known. What is not as well-known is another phenom-

enon that occurs in crystallization from melt in the presence

of a supercritical fluid like carbon dioxide. It is the devel-

opment of unique morphologies displaying ring-banded

spherulites. These arise from the helicoidal twisting of

radial crystal lamellae and the edge-on and flat-on do-

mains leading to the observation of ring-like morphologies

when viewed under a cross-polarized optical microscope.

The banded spherulites that develop consist of concentric

ridges and valleys typically having around 100 nm vertical

distances. The ridge area is constituted of the edge-on

lamellae aligned to the radial direction of the spherulites

while the valley area is formed by flat-on lamellae. A lesser

known and explored phenomenon is the formation of pores

in the crystallization process while these morphologies

develop. Pore formation arises from exclusion of carbon

dioxide from the crystal growth fronts and its accumula-

tion in the amorphous regions in between the growing

spherulitic domains, which eventually collapse and lead

to non-spherical, oriented pores.

In this presentation, using poly (3-hydroxybutyrate-

co-3-hydroxyvalerate) (PHBV) as an example, we will ad-

dress some important questions pertaining to the assessment

of melting point depression, the influence of pressure on

the progress of crystallization and the tendency of the

system to develop banded spherulites, and on the influence

of pressure on the pore formation. PHBV is a biodegradable

semicrystalline polyester which is naturally synthesized

by microorganisms which gives them their high degree of

stereo-regularity and high purity. Low nucleation density

due to the absence of the impurities allows uncommonly


large spherulites to grow during crystallization from the

melt, which facilitate the observations of the developments

of the unique morphologies.

The presentation will emphasize the need for ex-

ploration of the lowering of the melting temperature and

recrystallization of polymers from the melt in the presence

of carbon dioxide with a new perspective. The unique mor-

phologies that develop during crystallization in CO2 that

lead to ring-banded spherulites containing pores in be-

tween needs to be explored with a fresh look as an approach

to generate nano-porous structures. The pore formation

arising from the exclusion of CO2 from the crystal growth

front, and formation of the pores in the inter-crystalline

amorphous region during crystallization raises new ques-

tions and potentially offers new opportunities with respect

to the outcomes that can be expected in supercritical fluids

which may not be limited to CO2.

PANEL PRESENTATIONS

Panel III: Green Chemistry and Sustainable Technology

MODELING ThE VOLUMETRIC AND PhASE BEhAVIOR OF CO2 SySTEMS — SUCCESSES AND ChALLENGES

161

MODELING ThE VOLUMETRIC AND PhASE BEhAVIOR OF CO2 SySTEMS — SUCCESSES AND ChALLENGES

Amyn s. TejaSchool of & Biomolecular Engineering,

Georgia Institute of Technology; Atlanta, GA 303320100, USA;


The volumetric and phase behavior of CO2 systems is of

interest in a large number of green chemistry and sustain-

able technology applications, including polymer synthesis

and nanocomposite fabrication, flue gas and natural gas

processing, as well as drug encapsulation and nanopar-

ticle precipitation. Both theory and experiment suggest

that CO2 is able to interact with electron donating groups

to form weak Lewis acid-base complexes. These electron

donoracceptor or EDA complexes significantly affect the

phase behavior of CO2 systems of interest in the appli-

cations mentioned above. In spite of their importance

however, few thermodynamic models account for Lewis

acid-base interactions explicitly. There is much interest,

therefore, in thermodynamic models that incorporate weak

specific interactions, especially for systems at high pres-

sures that are typical of carbon dioxide processing.

The more successful models for associating systems

include versions of the Statistical Association Fluid The-

ory (SAFT), and several lattice fluid equations of state such

as those of Sanchez and Lacombe, and Panayiotou et al.

Although these equations of state can be used for both

phase and volumetric calculations, they generally require

self and cross-association parameters that depend on tem-


perature and/or molecular-weight. A significant amount

of experimental information is therefore required for their

use. Excess Gibbs energy models such as those of Painter,

Coleman and co-workers, on the other hand, have been

employed for describing specific chemical interactions

such as hydrogen bonds. However, these models are not

applicable to the calculation of volumetric properties. Re-

cently, two lattice models (a Compressed Lattice activity

coefficient model and an Associated Lattice Fluid equation

of state model) have been used successfully to correlate

phase equilibria and other properties in CO2 + polymer,

CO2 + cosolvent + polymer and CO

2 + ionic liquid sys-

tems over a range of pressures and temperature. These

models account explicitly for complex formation in the

lattice fluid partition function, and therefore contain phys-

ically meaningful parameters that are independent of tem-

perature or pressure. Moreover, it will be shown that in

situ Attenuated Total Reflection Fourier Transform Infrared

(ATR FTIR) measurements or CO2 absorption data can be

used to obtain one of the parameters in these models, with

experimental phase equilibrium data being used to obtain

the remaining adjustable parameter.

The application of the Compressed Lattice activity

coefficient model will be demonstrated by calculating both

cloud points and sorption equilibria in CO2 + PVAc and

CO2 + PLGA systems using a single adjustable parameter.

It will be shown that calculated equilibria are in good

agreement with measured values confirming that the mod-

el is able to extrapolate phase equilibrium data over a

range of pressures. It will also be shown that sorption

equilibria in CO2 + PLGA systems can be predicted using

information obtained from FTIR spectra and a single pa-

rameter obtained by fitting cloud point pressures in a ref-

erence system (CO2 + PLA in our case). This demonstrates

PANEL III: GREEN ChEMISTRy AND SUSTAINABLE TEChNOLOGy 163

that the model is capable of extrapolating information to

systems that have common functional groups. The depres-

sion of the glass transition temperature in the CO2 + PLA

system was also predicted without any additional param-

eters, demonstrating that the model can be used to predict

other properties. However, the compressible lattice mod-

el is inherently incapable of predicting volumetric prop-

erties.

This limitation has led to the development of the

Associated Lattice Fluid Equation of State model that is

able to calculate both phase equilibria and volumetric

properties. The EOS contains two mixture parameters —

the enthalpy of association ∆Ha and the equilibrium con-

stant at a reference temperature K0 — which do not depend

on temperature, pressure or molecular weight. The solu-

bility of CO2 in a number of polymers was correlated over

a wide range of temperatures and pressures using ∆Ha

values from independent FTIR measurements and K0val-

ues obtained by fitting solubility data. It is shown that the

new model is able to correlate solubility data within ex-

perimental error (maximum AAD of about 4%). In addition,

the extent of swelling of these polymers by CO2 can be

predicted without any adjustable parameters. The ALF EOS

therefore shows considerable promise in calculating both

phase equilibrium and volumetric data of CO2 systems.

Finally, the performance of these models in calcu-

lating phase equilibria and other properties of CO2 systems

will be used to identify future directions and challenges

in the modeling of such systems.

NANOPARTICLE SyNThESIS AND PROCESSING USING TUNABLE FLUIDS

165

NANOPARTICLE SyNThESIS AND PROCESSING USING TUNABLE FLUIDS

christopher L. KitchensDepartment of Chemical and Biomolecular Engineering,

Clemson University, USA;E-mail: [email protected]

Advancements in nanotechnology have led to a wide-

spread emergence of different techniques for nanoparticle

synthesis and application. The size and shape dependent

properties of nanomaterials motivate different synthesis

methodologies that afford morphological control. For cases

where morphology control is not afforded, monodispersed

populations of nanomaterials can be obtained by post-syn-

thesis fractionation based on size or shape. These frac-

tionation techniques are typically very solvent and energy

intensive as well as limited in scalability. A vital and often

overlooked component in the nanotechnology field is the

development of efficient, reduced-cost, and large-scale

methods for nanoparticle synthesis and processing. In re-

cent years, significant advancements have been made in

nanomaterial synthesis, processing, and application using

tunable fluids that provide promising alternatives to con-

ventional methods. Tunable fluids are a unique class of

fluids where the solvent’s thermophysical properties (eg.

solvent strength, density, diffusivity, interfacial tension)

can be tailored by controlling the system temperature and

pressure. Examples of tunable fluids are supercritical flu-

ids (SCFs), near-critical fluids (NCFs) and gas expanded

liquids (GXLs). For the first two, the temperature and pres-

sure of the system are either close to (NCFs) or above (SCFs)


the solvent’s critical point. In this region, the solvent prop-

erties are intermittent between those of a liquid and of a

gas; possessing the increased solvent strength and ther-

mal conductivity of a liquid along with the diffusivity of a

gas. Furthermore, the solvent is highly compressible under

these conditions, which enables control of these properties

by simply changing the pressure; hence the name tunable

fluids. GXLs consist of a gas and liquid mixture at pres-

sures below the vapor pressure of the gas phase. The tun-

able properties of GXLs rely on the high solubility of gasses

in liquids where the composition of the mixture is con-

trolled by the partial pressure of the gas phase. For exam-

ple, CO2 expanded hexane at 49 bars of CO

2 partial pressure

is 80 mol % CO2 and exhibits a volume expansion of near-

ly three times the hexane volume at ambient pressure. At

58 bar and 25 °C, the liquid phase is 91.3 mol % CO2, thus

a wide range of solvent properties can be achieved by

simply changing the CO2 partial pressure over a moderate

operating pressure range. The GXL liquid component can

consist of virtually any non-aqueous solvent, which imparts

a wide range of tunable fluid properties. Because the GXL

consists of a liquid solvent and a dissolved gas, the ther-

mophysical properties are again intermittent between the

two but at a much reduced pressure. This presentation

will review recent work in the synthesis and processing

of metal and metal oxide nanoparticles in each of these

tunable fluids; NCFs, SCFs, and GXLs. Specific topics will

include:

� Surfactant-mediated metal nanoparticle synthesis

in SC CO2 and CO

2 expanded liquids where the

tunable solvent properties govern the nanoparticle

synthesis.


� Metal oxide nanoparticle synthesis in near critical

and supercritical water.

� Post-synthesis purification and size-selective frac-

tionation of nanoparticles in GXLs.

� Uniform deposition of nanoparticles into wide-area

arrays using GXLs.

� Development of a thermodynamic interaction en-

ergy model to predict nanoparticle dispersibility as

a function of the tunable solvent properties.

� Small angle neutron scattering (SANS) measure-

ment of nanoparticle ligand shell thickness, solva-

tion, and degree of surface coverage in GXLs.

For nanoparticle synthesis, the solvent properties

influence the nanoparticle nucleation, growth, and stabi-

lization, which results in control over the nanoparticle size

and polydispersity. For polydispersed populations of nano-

materials, GXLs provide a novel medium for size and shape

selective fractionation, where particle dispersibility is a

function of the CO2 partial pressure. For example, dodec-

anethiol-stabilized gold nanoparticles are easily dispersed

in hexane. The progressive addition of CO2 to the hexane

will induce size-selective precipitation where the largest

nanoparticles precipitate at lower CO2 partial pressures

and the smaller nanoparticles precipitate at higher pres-

sures. This is akin to conventional liquid anti-solvent pre-

cipitation methods with the two notable exceptions: (1)

following fractionation, the pressure can be released and

all of the original solvents can be recovered, eliminating

the significant amounts of solvent waste and (2) the in-

creased nanoparticle diffusivity eliminates the need for

centrifugation which reduces the energy requirement and

facilitates the potential for large scale application.


Many nanomaterial applications require uniform

deposition of nanoparticles onto a surface. Conventional

solvent-based methods can result in non-uniformities from

interfacial drying effects or require slow volatilizing sol-

vents. For SCFs, spray applications are possible. For GXLs

the CO2 pressure can be increased beyond the vapor pres-

sure and then heated beyond the critical point before re-

leasing the pressure, enabling critical point drying and

preservation of the nanoscale structure. For each of these

applications, a fundamental understanding of the un-

derlying thermodynamics behind the nanoparticle dis-

persibility facilitates our ability to produce well-defined

nanomaterials for a diversity of applications in a sustain-

able manor.

REFERENCES

f Hart et al., J. Supercritical Fluids, 79 (2013) 236-243.

f Von White II et al., Industrial & Engineering Chemical Research, 51(14)

(2012) 5181-5189.

f Von White II et al., J. Physical Chemistry C, 114(39) (2010) 16285-16291.

f Anand et al., Industrial & Engineering Chemical Research, 47(3) (2007)

553-559.

f McLeod et al., Langmuir, 21(6) (2005) 2414-2418.

f McLeod et al., Nano Letters, 5(3) (2005) 461-465.

f Kitchens et al., Industrial & Engineering Chemical Research, 43(19)

(2004) 6070-6081.

GREEN PROCESSES FOR hIGh ADDED-VALUE PRODUCTS ExTRACTION FROM NATURAL SOURCES

169

GREEN PROCESSES FOR hIGh ADDED-VALUE PRODUCTS ExTRACTION FROM NATURAL SOURCES

E. ibáñez Instituto de Investigación en Ciencias de la Alimentación

CIAL (CSIC-UAM); C/Nicolás Cabrera 9, Campus de Cantoblanco,

28049 Madrid, España; E-mail: elena@ifi .csic.es

At present, there is an enormous interest in trying to give

new answers to one of the main societal challenges in our

society: that is, sustainability. Sustainability can be under-

stood as a rational way of improving processes to maximize

production while minimizing the environmental impact

or, in the words of the Environmental Protection Agency

(EPA), “sustainability creates and maintains the conditions

under which humans and nature can exist in productive

harmony, that permit fulfilling the social, economic and

other requirements of present and future generations”.

Bearing this in mind, many aspects can be considered in

this framework, ranging from the rational use of resources

to the modern concept of biorefinery which, undoubtedly,

may change our perception of the industrial processes in

this century. Considering this framework, the production

of valuable products from natural sources is of high inter-

est since it can allow to consolidate the idea of sustainable

processes.

In the area of food science and nutrition, the finding

of new bioactive compounds able to prevent or improve

the health status of the individuals, mainly acting as food

supplements or functional food ingredients, is of upmost

importance nowadays. Considering the tremendous mar-


ket value of the functional food industry, it is easy to un-

derstand the enormous interest in new compounds, extracts

and products that, once its efficacy has been proved with

scientific evidences, should be produced at large scale. A

good example of this are, for instance, compounds such

as antioxidants, associated to lower risk of certain diseas-

es that are nowadays widespread in the developed coun-

tries, such as coronary heart diseases and cancer [1,2].

Although they have been investigated in the last years

and some of them have provided with evidence about their

effect, much more research is needed to prove their real

efficacy in human beings. Undoubtedly, nature can be con-

sidered an unlimited source of bioactives and the search

of new compounds with improved activities have ran par-

allel to the search for new natural sources. It is well known

that there are many families of compounds with proved

antioxidant activity, such as phenolic compounds, carot-

enoids and tocopherols, which are easily available in the

vegetal kingdom. But at present there is a huge interest

in the potential use of marine natural sources to obtain

these bioactives, mainly considering their huge diversity,

in terms of number of different species that might be po-

tentially used, their sometimes unique chemical structures

and their ability to work as natural bioreactors potentiat-

ing the synthesis of valuable compounds depending on

the cultivation conditions. Moreover, the biorefinery con-

cept has been recently associated to algae as one of the

most sustainable ways to improve the efficient use of algae

biomass [3].

Moreover, researchers are facing new challenges

in the development of new extraction processes to obtain

valuable products from natural sources. Up to now, tradi-

tional extraction methods (mainly S-L extraction) have

been used to extract bioactives; these methods have sev-


eral drawbacks like they are time consuming, laborious,

have low selectivity and/or low extraction yields. New

challenges involve the development of fast, selective, ef-

ficient, sustainable, green (without using toxic organic

solvents), with high yields and at lower cost. The tech-

niques able to meet these requirements are, among others,

those based on the use of compressed fluids such as su-

percritical fluid extraction (SFE), pressurized liquid ex-

traction (PLE) and subcritical water extraction (SWE), which

are among the more promising processes [4, 5]. Depending

on the polarity of the green compressed fluid, different

“green” or environmentally clean technologies can be used,

as can be seen in Figure 1.

high polarityWater Pressurized solvents

SWE, PLE

Medium polarityPressurized solventsscCO2 + polar modifiers (EtOH)Gas Expanded Liquids

PLE, SFE, GXL

Low polarityscCO2

LimonenePLE, SFE

Figure 1. Green solvents and environmentally friendly technologies used

to extract high added-value products from natural sources

In this presentation, different examples will be

shown, considering different raw materials such as plants,

algae and food by-products and employing the above men-

tioned green technologies. With this approach we will try

to demonstrate the possibility of tuning the extraction con-

ditions depending on the target compound(s) and the raw

material to achieve sustainable processes.


Among other examples, some research works devel-

oped in our laboratory will be presented dealing with the

direct extraction, using SFE (Supercritical Fluid Extraction),

of carotenoids (astaxanthin) from Neochloris oleoabundans

biomass; the isolation, using gas expanded liquids (GXLs),

of gamma-linolenic acid from Spirulina; the extraction of

antioxidants from rosemary using integrated processes

of extraction and particle formation (WEPO, Water Extrac-

tion and Particle formation On-line); and the use of LCA

(Life Cycle Assessment) tool to evaluate the environmen-

tal impact of different green extraction processes (SFE,

SWE, WEPO).

ACKNOWLEDGMENTS

This work was financed thanks to AGL2011-29857-C03-01 (Ministerio de

Economía y Competitividad) and ALIBIRD, S2009/AGR-1469 (Comunidad

de Madrid) projects.

REFERENCES

[1] A. Harris, S. Devaraj, I. Jialal, Oxidative stress, alpha-tocopherol thera-

py, and atherosclerosis, Current Atherosclerosis Reports, 4(5) (2002)

373-380.

[2] R. Brigelius-Flohe, F.J. Kelly, J. T. Salonen, J. Neuzil, J-M Zingg, A. Azzi,

The European perspective on vitamin E: current knowledge and future

research, The American J. Clinical Nutrition, 76(4) (2002) 703-716.

[3] E. Ibañez, A. Cifuentes, Benefits of using algae as natural sources of

functional ingredients, J. Science of Food and Agriculture, 93 (2013)

703-709.

[4] M. B. King, T. R. Bott, Extraction of natural products using near-critical

solvents; Blackie Academic & Professional, Glasgow, 1993.

[5] J. A. Mendiola, M. Herrero, A. Cifuentes, E. Ibáñez, Use of compressed

fluids for sample preparation: Food applications, J. Chromatography

A, 1152(1-2) (2007) 234-246.

SCIENTIFIC PRODUCTION OF SUPERCRITICAL FLUID TEChNOLOGy WORLDWIDE: ROLE OF ACADEMIA

173

SCIENTIFIC PRODUCTION OF SUPERCRITICAL FLUID TEChNOLOGy WORLDWIDE: ROLE OF ACADEMIA

socrates Quispe-condoriSchool of Food Engineering, Universidad Peruana Unión;

Alt. Km 19 Carretera Central, Ñaña, Lima, Peru; E-mail: [email protected]

Since benefits of supercritical fluids were recognized in

the 70’s, extensive research have been carried out on their

potential applications (supercritical fluid extraction, en-

ergy applications, analytical applications, supercritical

water oxidation, supercritical fluid fractionation, super-

critical fluid reactions, applications in material science,

cleaning technology, fine particle production, encapsula-

tion, foaming, green chemistry / engineering, sustainabil-

ity / bioenergy / biomass, blending in supercritical media,

polymerization / copolymerization, catalysis, material syn-

thesis, drying, distillation, and crystallization) by several

research groups. Although some of the technologies were

implemented at industrial and commercial scales, scien-

tific literature often presents new applications of super-

critical fluids. Many reviews were presented about the

progress of supercritical fluid technology in different areas.

However, there are no references related to the analysis

of scientific production in this technology. Scientific pro-

duction is one of the critical factors for country develop-

ment. Studies related to the production of information allow

to evaluate the scientific activity and its development,

identifying significant trends, characterizing representa-

tive institutions, scientific working groups and research


topics. Bibliometrics, when applying statistical methods,

enables the analysis of scientific production from literature

sources, determining the research activity in a quantita-

tive way. During the last decades, bibliometrics has been

applied in all knowledge areas, usually through descriptive

reports.

The objective of this work is to determine scientif-

ic production of the applications of supercritical fluids

through a descriptive bibliometric analysis. The publica-

tion of articles, reviews, books and conference manuscripts

from all countries were analyzed, giving special attention

to the participation of academia in the development and

diffusion of this technology, evaluating its production in

terms of its international impact, and identifying the most

productive scientific institutions. Scientific production was

evaluated in the Scopus database (www.scopus.com). Sco-

pus is the largest database of scientific literature, covering

all areas of science, technology, medicine, social sciences

and arts & humanities. Currently, it contains a record of

approximately 50 million bibliographic references from

21000 titles and 5000 publishers. “Supercritical” term in

Title field was used as search strategy in the database.

The following bibliometric indicators of productivity were

determined: Documents per year (from 1970 to September

2013), document type, scientific production by country,

distribution for knowledge areas, number of papers per

author, and publications for journals. Macro trends that

guided the development of supercritical fluid technology

in countries and institutions were identified.

The total number of reported references in Scopus

database were 26 923, distributed in Articles (77.20%), Con-

ference Papers (15.86%), Reviews (4.42%), Articles in Press

(0.54%), Books (0.23%) and Conference Review (0.23%). It

is observed that United States (19.51%), China (16.68%),


Japan (10.39%), Germany (4.70%) and France (4.38%) have

the best indicators in terms of production of scientific

articles. Development indicators of science in terms of

publications in Latin America are farther away from the

standards of countries with the highest scientific and tech-

nological development. Brazil (1.75%), Argentina (0.42%)

and Colombia (0.16%) are the most productive. Regarding

the field of application, it was observed that scientific

production is oriented at Chemistry (22.23%), Chemical

Engineering (16.28%), Engineering (12.10%), Materials

Science (11.98%), Physics and Astronomy (10.28%), Ener-

gy (6.20%), Environmental Science (4.97%), Biochemistry,

Genetics and Molecular Biology (4.66%), Agricultural and

Biological Sciences (3.36%), and Pharmacology, Toxicolo-

gy and Pharmaceutics (2.15%). Main sources of diffusion

of scientific production are Journal of Supercritical Fluids

(14.67%), Industrial and Engineering Chemistry Research

(5.24%), Journal of Chromatography A (4.43%), Fluid Phase

Equilibria (3.67%) and Journal of Chemical and Engineer-

ing Data (2.15%). Universities are the leading scientific

productive institutions compared to the research centers.

Institutions with highest scientific production are Tohoku

University (1.36%), University of Tokyo (1.11%), Kyoto Uni-

versity (0.99%), Tsinghua University (0.83%) and Zhejiang

University (0.82%). The research center with highest sci-

entific production is the National Institute of Advanced

Industrial Science and Technology (1.11%).

MODELING OF SUPERCRITICAL CARBON DIOxIDE ExTRACTION OF JATROPhA (JATRophA cuRcAs L.) SEEDS

177

MODELING OF SUPERCRITICAL CARBON DIOxIDE ExTRACTION OF JATROPhA (JATRophA cuRcAs L.) SEEDS

suzana yusup, Vladan Mićić, yi herng chanUniversiti Teknologi PETRONAS;

Bandar Seri Iskandar, 31750, Tronoh, Perak, Malaysia; E-mail: [email protected]

This work investigates the extraction of Jatropha seeds

utilizing supercritical carbon dioxide. The yield of the ex-

traction increased with time and the extraction process

can be clarified into slow and fast extraction region. In the

modelling of the supercrital extraction process, Rever-

chon-Sesti Ossea model and its modified form were used

to compare with the experimental extraction yield and

both models were found to be in good agreement with the

process.

ORGANOCATALySIS IN SUPERCRITICAL CO2: A NEW EFFICIENT CATALyST FOR ASyMMETRIC ALDOL REACTIONS

179

ORGANOCATALySIS IN SUPERCRITICAL CO2: A NEW EFFICIENT CATALyST FOR ASyMMETRIC ALDOL REACTIONS

Reinaldo BazitoInstituto de Química,

Universidade de São Paulo (USP); Av. Prof. Lineu Prestes, 748-B8T, Sala 811, Cidade Universitária,

05508-000 São Paulo, SP, Brazil; E-mail: [email protected]

The enantiomers of a chiral compound have identical

chemical properties but may present different biological

action. There are many examples where one of the enan-

tiomers is a very effective drug while the other is not as

effective or may even be toxic. This has lead to extensive

research on synthetic methodologies to produce a single

enantiomer for target molecules containing stereogenic

centers (enantioselective or asymmetric synthesis), spe-

cially using catalysis.

Two major approaches have been used for asymet-

ric synthesis: asymmetric catalysis, where the catalyst is

usually a chiral transition metal complex; or biocatalysis,

where the catalyst is an enzyme. A new approach, how-

ever, started to gain importance recently, the asymetric

organocatalysis, where the catalyst is a small chiral or-

ganic molecule added to the reaction media in substoi-

chiometric quantities. These molecules can be natural

chiral compounds from the “chiral pool”, such as amino

acids, alkaloids, sugars and so on, providing a greener

approach to enantioselective synthesis.

The Aldol condensation is a very important reaction

in organic synthesis, with its asymmetric version being

used to form a new carbon-carbon bound in an enantiose-


lective way. Organocatalysis using chiral amino acids,

especially L-proline, have been successfully employed for

this reaction, providing a greener catalyst, but there are

still some drawbacks, including a high E factor (high waste/

product ratio), mainly due to the use of organic solvents

and the need to neutralize the base used in stoichiometric

quantities, and long reaction times. New reaction media

that could improve selectivity/yield, with shorter reaction

times and reduced waste generation are being sought for.

Supercritical carbon dioxide is one of these possible

new reaction media, because of its unique properties: an

environmentally benign solvent with accessible critical

point (Tc = 304.2 K, Pc = 7.38 MPa), very good transport

properties, unique phase behavior, among other interest-

ing properties. The combination of this neoteric solvent

with organocatalysis for the Aldol condensation reaction

is very promising and was the subject of this work.

Our group has recently studied a series of proline

derivatives for the organocatalysis of Aldol type reactions

in sc-CO2 or a combination of this solvent with an imidaz-

ole-based ionic liquid (1-allyl-3-alkyl-imididazolium chlo-

rides).

The first Aldol reaction to be studied was the con-

densation reaction between acetone and 4-nitrobenzalde-

hyde, resulting in a β-hydroxy ketone (as the chiral addition

product) and a α,β-unsaturated ketone (as the undesired

achiral elimination product). The catalysts employed for

this reaction were L-proline, used as a standard, and the

following L-proline derivatives: (R)-thiazolidine-4-carbox-

ylic acid (thio-L-proline); (2S,4R)-4-(dimethyl(phenyl)silyl)

oxy-pyrrolidine-2-carboxylic acid (dimetilphenylsilyloxy- L-

proline); (2S,4R)-4-(tert-butyldimethylsilyloxy)pyrrolidine-

2-carboxylic acid (t-butyl-dimetilsilyloxy-L-proline); (2R,3R,

4R,5R,6S)-2-(acetoxymethyl)-6-(pyrrolidine-2-carboxamido)


tetrahydro-2H-pyran-3,4,5-triyl triacetate (peracetyl-glucos-

amine-L-proline). The influence of pressure, temperature,

presence of ionic liquid and type of catalyst were evaluated.

The best results were obtained with one of the si-

lylated catalysts, tert-butyldimethylsilyloxy-L-proline, with

very good yields and enantiomeric excesses (e.e.) of the

product, in shorter reaction times, especially in the pres-

ence of the ionic liquid. Yields around 54%, with enan-

tiomeric excess around 79%, could be obtained in 2 h of

reaction, at 150 bar and 40 oC.

Another Aldol reaction that have been studied is

the condensation reaction between cyclohexanone and

4-nitrobenzaldehyde, using as catalysts L-proline (as a

standard), t-butyl-dimetilsilyloxy-L-proline, and a helicoidal

polyacethylene containg L-proline groups, resulting in the

chiral anti/syn addition product. The influence of reaction

time and the presence of additives (acetic acid or ionic

exchange resin) were investigated, for the same pressure

and temperature used for the previous reaction (150 bar,

40 oC).

Both catalysts were more effective than L-proline

resulting in higher yields and enantiomeric excesses in

shorter times. The best results were obtained with the

tert-butyldimethylsilyloxy-L-proline catalyst, using ion ex-

change resin, with an isolated yield of 71% and an e.e. of

91% (for the anti product).

The proline derivatives were effective organocata-

lysts for the Aldol reactions in sc-CO2, specially the silylat-

ed derivative, presenting shorter reactions times than in

organic solvents and good yields and enantiomeric ex-

cesses.

PhyTOChEMICAL PRODUCTION FROM BIOMASS USING PRESSURIzED FLUIDS

183

PhyTOChEMICAL PRODUCTION FROM BIOMASS USING PRESSURIzED FLUIDS

Marleny D. A. saldañaDepartment of Agricultural, Food and Nutritional Science,

University of Alberta; Edmonton, Alberta, T6G 2P5, Canada;


Pressurized fluids, such as subcritical water, pressurized

aqueous ethanol and supercritical CO2 (scCO

2) are consid-

ered green and environmentally friendly solvents that can

be used for production of phytochemicals from a variety

of Canadian biomasses as well as for various reactions.

Phytochemicals, such as phenolic acids are found in var-

ious biomasses as hydroxybenzoic and hydroxycinnamic

acids. These compounds have antioxidant and antimicro-

bial activities and their consumption have been correlat-

ed with a lower incidence of cancer, heart disease, and

diabetes. Carbohydrates are also considered important

phytochemicals that can be used in a number of food,

pharmaceutical and fuel applications. Research in my lab-

oratory has focused on solubility determination of select-

ed phenolic acids and sugar compounds in pressurized

water as well as the use of pressurized fluids to obtain

these phenolics and carbohydrates from biomasses, such

as potato peel, lentil husk, and barley hull, among others

to later be used in various applications. For solubility of

selected phenolic acids and selected sugars in pressurized

water, experimental data were obtained at pressures of

15-120 bar and temperatures of 100-180˚C using a dynam-

ic flow high pressure system. The results obtained showed


that the solubility of sugars (glucose and lactose) in pres-

surized water increase with an increase in temperature.

However, with the increase of pressure from 15 to 120 bar,

the solubility of both sugars in pressurized water decreased.

For selected phenolic acids, solubility was affected by

temperature. Dissolution of selected phenolic acids in

pressurized water increase, remain stable (gallic acid) or

decreased (3-4-hydroxyphenyl propionic acid and 4-hy-

droxybenzoic acid) with an increase of temperature. Pres-

sure influenced aqueous solubility of gallic acid from 100

to 150˚C, but had no effect on the solubility of the other

phenolic acids selected in the temperature interval stud-

ied. Experiments of phenolics and carbohydrates removal

of selected biomasses using pressurized fluids were per-

formed using a dynamic flow high pressure system at dif-

ferent temperatures ranging from 100 to 260˚C, pressures

up to 200 bar and times up to 180 min. Other variables

evaluated for selected biomass systems were static hold-

ing time and pH. Then, experiments of enzymatic synthe-

sis of selected phenolic compounds in oil in scCO2 media

were performed in a laboratory-scale supercritical fluid

system at different temperatures ranging from 40 to 80˚C,

pressures from 4 to 350 bar and time up to 53 h. In addition,

the use of selected phenolic compounds in milk was eval-

uated at temperatures of 60-120˚C, pressures of 1000-6000

bar and times up to 15 min. Extracts and residues obtained

after biomass treatment using pressurized fluids were eval-

uated for their individual concentrations of phenolic and

carbohydrate compounds, total phenolic and carbohydrate

contents, and antioxidant activity. Results indicated that

the total phenolic and carbohydrate contents and antiox-

idant activity increased with temperature. The highest

total carbohydrates, total phenolics, and total antioxidant

activity of each biomass were obtained at optimized con-


ditions of pressure, temperature and static holding time

using pressurized fluids. For example, the highest carbo-

hydrate extraction (576.1±19.1 mg/g hull) from barley hull

was obtained using pressurized aqueous ethanol with low

ethanol concentration (12%, v/v), but this pressurized flu-

id was not the best for phenolics removal. For the applica-

tions, results have shown that scCO2 is a promising green

solvent for the enzymatic synthesis of phenolic lipids. In

addition, the use of selected phenolic acids in milk retained

valuable components while inactivating spores (Bacillus

amyloliquefaciens) and the alkaline phosphatase enzyme

using high pressure processing assisted by temperature.

Phytochemical production from selected biomasses using

pressurized fluids and its uses in reactive system applica-

tions were demonstrated.

PANEL PRESENTATIONS

Panel IV: SCFs as Working Fluids / Process Technology and Design

SyNThESIS AND POWDER GENERATION OF POwDER COATINGS USING SUPERCRITICAL CARBON DIOxIDE

189

SyNThESIS AND POWDER GENERATION OF POwDER COATINGS USING SUPERCRITICAL CARBON DIOxIDE

i. Bochon, M. petermannUniversity Bochum;

Universitaetsstr. 150, 44801, Bochum, NRW, Germany; E-mail: [email protected]

The use of powder coatings is a promising way to reduce

organic solvents emission, as the application of such coat-

ings is completely emission free. Unfortunately the syn-

thesis of powder coating components is classically made

with organic solvents, which is leading to emissions in the

manufacturing step. Powder coatings consist of two main

components, a binder and a hardener, which can be cross-

linked via a chemical reaction, induced by heat or radia-

tion. Beside these polymeric main components, additives

like pigments, fillers, degassing agents etc. have to be

added. To manufacture powder coatings different indus-

trial steps are necessary. First the polymers have to be

synthesized and granulates have to be formed. In a second

step the polymers and the other components have to be

homogenized in drum mixers. This mixture is melted, rolled

to a plate, solidified and later broken into flakes. These

flakes have to be ground to the final powder coatings. For

this step, air-jet mills are used to gain powders with av-

erage particles sizes of 30-40 micrometers. Overall the

classical powder coating manufacturing process is time,

energy and cost intensive and additional solvent emissions

have to be accepted during polymer synthesis. The aim of

this work is to substitute the classical multi-step process

with a single continuous process, using supercritical car-


bon dioxide as auxiliary media. In a first step the synthe-

sis of the polymer is made in supercritical CO2 and, by

adjusting the process parameters can be done in a single

phase regime. This is leading to high space-time yields.

The synthesis of a powder coating binder in supercritical

CO2 was first published by Beuermann et al. [1,2] In a

second step, without depressurization, the additional com-

ponents of a powder coating have to be added — mainly

the hardener component. A surplus of carbon dioxide is

leading to a further reduction of the polymer viscosity and

is easing the spray of such mixtures. To form the final pow-

der coating, the so called PGSS (particles from gas satu-

rated solutions) process is used [3]. In this process, a gas

saturated mixture is expanded via a nozzle into a spray

tower. The pre-expansion pressure is lying in the area of

20 MPa and the pre-expansion temperature is slightly

above the melting point of the components. During the

expansion, the dissolved gas is set free and is leading to

a fine droplet formation. Additionally, the gas cools down,

caused by the Joule-Thomson effect. Due to the cooling,

the droplets solidify and a powder coating is formed. The

expansion can be additionally used for the cleaning of the

polymers. Residue monomers, left over after the reaction

can be stripped away by the expanding gas. The super-

critical fluid process is characterized by a single step de-

sign and is leading to no solvent emission. The contribution

will first illustrate the optimization of the polymer reaction

of the binder component in supercritical fluids. These ex-

periments were carried out first in a batch reactor and

later in a continuous tubular reactor. In a second part the

continuous single step process will be illustrated. This

plant consists of the tubular reactor and a PGSS plant for

the particle generation. The reactions carried out in com-

pressed CO2 are characterized by high yields of 80-90%,

PANEL IV: SCFS AS WORKING FLUIDS / PROCESS TEChNOLOGy AND DESIGN 191

short reaction times of about 20 minutes and a small

polydispersity of PDI ≤ 2 of the synthesized polymer. The

experiments show that the targeted average molecular

weight of Mn ≈ 2500 g/mol can be reached in presence

of the compressed gas. The contribution will end with

ready-made powder coatings, gained with a plant, which

is combining the tubular reactor with the expansion step

of the PGSS plant and is leading to particle systems which

have mean particle sizes, suitable for powder coating ap-

plications.

REFERENCES

[1] S. Beuermann, M. Buback, C. Isemer, A. Wahl, Homogeneous free-

radical polymerization of styrene in supercritical CO2, Macromolecular

Rapid Communications, 20(1) (1999) 26-32.

[2] S. Beuermann, M. Buback, M. Jürgens, Free-radical terpolymerization

of styrene and the two methacrylates in homogeneous phase con-

taining supercritical CO2, Industrial Engineering Chemistry & Research,

42(25) (2003) 6338-6342.

[3] E. Weidner, M. Petermann, K. Blatter, V. Rekowski, Manufacture of

Powder Coatings by Spraying of Gas-Enriched Melts, Chemical Engi-

neering & Technology, Wiley-VCH, Weinheim, (24) (2001) 529-533.

SUPERCRITICAL CO2 AS WORKING FLUID IN ThE NATURAL GAS INDUSTRy

193

SUPERCRITICAL CO2 AS WORKING FLUID IN ThE NATURAL GAS INDUSTRy

christopher g. spilsburyBG Group, Thames Valley Park;

RG6 1PT, Reading, Berkshire, UK; E-mail: [email protected]

The Natural Gas industry represents a potential opportu-

nity in the application of supercritical carbon dioxide as

a working fluid for the efficient transport of natural gas.

This is the subject of this perspective. The goal of many

companies such as the BG Group is to reduce the carbon

footprint of business operations and improve efficiency.

BG Group is seeking to improve efficiency of its operations

at a rate of 2% per annum. The natural gas industry makes

extensive use of large gas compressors, some as large as

50 MW and more. These gas compressors are used for

many duties including pipeline gas compressors and re-

frigerant gas compressors used in gas liquefaction plants

(LNG). Many of these gas compressors are driven by gas

turbines. The industry also uses gas turbine driven gen-

erator sets, often to generate the electricity used on remote

gas production and gas processing facilities. The BG Group

itself has more than 100 gas turbine driven machines dis-

tributed across it assets. Gas turbine driven equipment is

used in both an onshore and offshore environment. Many

of these gas turbines are installed as simple open cycles

without waste heat recovery. To date this has been for

many reasons including how to utilise the exhaust waste

heat effectively and in some case space and weight con-

straints. Supercritical CO2 applied to energy recovery from


these gas turbine exhausts has great potential. A super-

critical CO2 brayton or rankine cycle for energy recovery

could recover the heat to electrical energy or motive pow-

er for the gas compressors. These cycles are potentially

as efficient as steam cycles, simpler than steam or organ-

ic rankine cycles, use a safe working fluid and have po-

tentially the lowest space requirement. There is potential

to utilise supercritical CO2 as a component in providing

highly efficient local solution for gas industry driven equip-

ment without the need for extensive power and heat dis-

tribution systems with their associated energy losses. For

those gas turbine in the BG Group there is potential to

recover over 1 GW of power. There is a significant role that

supercritical CO2 as working fluid could play in improving

the industry efficiency. With typical machine duties in the

range of 5 to 50 MW the industry utilises of machines of

an ideal size to develop and demonstrate supercritical CO2

technology. The gas industry continues to grow with in-

vestment in new pipelines, compression systems and gas

liquefaction facilities providing opportunity for investment

in heat recovery using supercritical CO2 as working fluid.

There are technical challenges for this technology in the

size range being considered, particularly in the CO2 ex-

pansion turbine design. The compactness of supercritical

CO2 may make this the future technology of choice for

energy recovery on offshore installations to make these

installations the most energy efficient. It is very possible

that mechanical work derived from the supercritical CO2

turbines may be integrated to supplement the mechanical

power of the gas turbine prime mover in one highly effi-

cient package. One day we might see a mechanical driv-

er package with a combined efficiency of over 55%. The

natural gas industry has an opportunity to play a signifi-

cant role in the development and implementation of su-

percritical CO2 power systems.

hyDROCARBON GROUP SEPARATION USING SUPERCRITICAL CO2: ThE LAST 20 yEARS AND ThE FUTURE AT PETROBRAS R&D CENTER

195

hyDROCARBON GROUP SEPARATION USING SUPERCRITICAL CO2: ThE LAST 20 yEARS AND ThE FUTURE AT PETROBRAS R&D CENTER

flávio c. Albuquerque, Arthur de Lemos Scofi eld,

Marcos vinícius Riscado cabralCENPES – PETROBRAS R&D Center;

Av. Horácio de Macedo, 950, Cidade Universitária, 21941-915, Rio de Janeiro, RJ, Brazil;


M. Angela A. MeirelesLASEFI/DEA/FEA (School of Food Engineering),

UNICAMP (University of Campinas);R. Monteiro Lobato, 80, 13083-862, Campinas, SP, Brazil

Fossil fuels are complex mixtures constituted by hydro-

carbons and N,S,O-compounds as contaminants, with a

wide distillation range. The complete separation of these

mixtures in the individual constituents is feasible only for

the lighter fractions, using high resolution analytical tech-

niques, like 1D- and, more recently, 2D-gas chromatogra-

phy. To analyze the whole crude oil or its heavier fractions,

group separation according to the chemical nature of their

components is usually required. The determination of hy-

drocarbon families, such as saturated hydrocarbons, ole-

fins, diolefins, and hidrocarbons according to the number

of aromatic rings is essential for the petroleum industry

in many situations. Although fairly simple, considering the

huge number of components, it provides enough informa-

tion to evaluate quality of crude oil or fuels, to infer about

their stability, or to optimize refining processes and cata-

lysts. Unfortunately, most of these analyses, usually per-

formed by normal phase liquid chromatography or solid

phase extraction, suffer with different drawbacks. To cir-


cumvent the lack of a universal detector for liquid chro-

matography, separations have sometimes to be performed

through preparative procedures, which are often lengthy

and lead to loss of lighter components. The choice of an-

alytical-scale liquid chromatography with the refraction

index detector is restricted to the analysis of narrow dis-

tillation cuts or products, due to differences in the response

factors of the components.

In the mid of 80’s there was a rebirth of supercriti-

cal fluid chromatography (SFC), which promised faster and

more efficient separations than high-performance liquid

chromatography. By the beginning of 90’s, ASTM approved

D 5186 standard, for determination of mononuclear and

polynuclear aromatic hydrocarbon contents in diesel fuels

by SFC. The usage of polar stationary phase in combina-

tion with CO2, as mobile phase, allowed separations by

hydrocarbon groups with flame ionization detector (FID).

CENPES / PETROBRAS purchased its first commercial

supercritical fluid chromatograph in 1995, and since then

it has extended the application of SFC to all hydrocarbon

liquid streams produced in a petroleum refinery.

CENPES has also set up methods to determine oth-

er hydrocarbon groups, like olefins and diolefins in light

and middle hydrocarbon distillates. Although it is gener-

ally assumed that olefins are absent from petroleum, this

compounds are formed during catalytic or thermal crack-

ing of petroleum heavy fractions. These hydrocarbons can

either contribute to increase octane number of gasoline

fuels, or they also play an important role in gum and sol-

ids formation. ASTM has approved another standard test

method (D 6550) to determine total olefins in gasoline fu-

els, also with CO2 as mobile phase and FID detection, but

adding a silver-impregnated column for selective trapping

of unsaturated components, and two 6-port, 2-position


valves, to change flow path of the mobile phase and back-

flush the olefinic components. A different approach was

adopted in CENPES, in which a small, home-made, high-

ly silver-impregnated trap is used. In addition, a different

sequence of timed events for valves actuation during the

analysis was established. These changes make possible to

determine not only olefins, but also saturated and aromatic

hydrocarbons by ring number in a single chromatograph-

ic run. While ASTM D 6550 is restricted to the analysis of

gasoline fuels, CENPES’ method can be applied to the

entire range of atmospheric pressure distilled fractions.

Conjugated diolefins constitute a small fraction of

the total olefins and are strongly related to the instability

of fuels. An analytical method was developed to determine

these substances, again using SFC with conditions simi-

lar to the previous ones, except the detection mode: instead

of FID, UV detection at 240 nm was chosen. Non-aromatic

and aromatic compounds are chromatographically sepa-

rated and conjugated diolefins are the only substances

belonging the non-aromatic peak that absorb UV in this

wavelength. The method is usually applied to petroleum

light distillates (i.e. naphtha fractions), in which most of

the conjugated diolefins concentrate.

Sulfur-containing components can also be grouped

and determined by SFC coupled with sulfur-selective che-

miluminescence detector. Group separation of fossil fuels

by preparative SFC is under investigation to provide green-

er and faster separations, while allowing the isolation of

fractions for further chemical characterization.

CROSS INDUSTRy INTEGRATION FOR POWER PLANTS OF ThE FUTURE AND SUPERCRITICAL FLUIDS

199

CROSS INDUSTRy INTEGRATION FOR POWER PLANTS OF ThE FUTURE AND SUPERCRITICAL FLUIDS

Aydin K. sunolUniversity of South Florida;

Tampa FL 33620, USA;E-mail: [email protected]

Desire for a sustainable world, does should, and will con-

tinue to demand a critical look at the way we meet our

basic needs beyond the ways we are used to even in the

highly capital intensive basic industries which are known

to be very risk averse with demands and incentives for

disruptive changes are incremental and where cross in-

dustry fertilization is only blossoming. This presentation

will provide a forum for discussion of supercritical fluid

cycles, their current utilization and potential impact with

relaxation of cross industry barriers to entry. Specific ex-

amples will include biomass or coal to liquids plant inte-

gration power plants, solar and nuclear power implications,

sequestering implications and integration, and natural

product processing and power integration, and urea/am-

monia production in integrated gasification combined cy-

cle power plants. One of the examples is elaborated in the

abstract.

Coal to liquid conversion, for either liquid fuel or

chemical products, and power go back thousands of years.

Indirect processes that utilize gasification and subsequent

gas to liquids conversion using Fischer Tropsch type syn-

thesis seems be the choice in expense of direct liquefaction

paths that involve hydrogenation of coal using hydrogen

and/or a solvent that itself can donate hydrogen to coal.


Due to technological and environmental challenges as-

sociated with direct routes, less efficient indirect routes

attracted more interest, in terms of development and com-

mercial effort. A noteworthy exception to the choice is

Shenua plant in Northern China that produces/processes

millions tons/year of coal to liquid fuels using direct routes.

The world’s largest coal to liquids plant employs direct

route at a cost of about $45-$65/barrel.

One interesting direct coal conversion process was

National Coal Board’s (UK) Supercritical Gas Extraction

route using typically Toluene as a solvent. Although per-

cent extracts were lower (around 40-45%), the process

yielded hydrogen rich extract and residue that was as re-

active as the parent coal. The extracts were less condensed

and therefore a lot more amenable to efficient hydrocrack-

ing. The cumbersome solid-liquid separation train was

eliminated while solvent recovery and environmental is-

sues were minimized. The author was first to employ Su-

percritical Water successfully as a solvent for extraction

[1] and similar results were independently reported later

(e.g. Despande et. al. [2]). Water can indeed solubilize hy-

drocarbons at supercritical conditions. We also proposed

to integrate direct and indirect coal liquefaction synergis-

tically benefiting from extract residues that have the re-

activity and energy content of the parent coal.

Power plants that utilize supercritical water have

efficiencies around 45% and have been around for some

time. Thus, the technical know-how for working with su-

percritical water does exist. Power plants that utilize super-

critical water can be a source of solvent for Supercritical

Coal extraction plants. The existent coal feed preparation

and post environmental clean-up facilities are also prem-

ises that make such an integrated technology feasible.

These facilities also include water treatment that benefits


the solvent extraction cause. It is important to point out

that corrosion issues associated with supercritical water

oxidation of waste are not applicable to use of supercriti-

cal water as coal solvent due to non-oxidative nature.

Carbon dioxide capture and sequestering in power

plants as well as coal to liquid plants offer synergistic

integration opportunities as well. For instance, homoge-

nous catalysts that can be used residue gasification, can

be used in capture carbon dioxide. Another possibility is

to co-production urea, a fertilizer.

Features of holistic piloting and modeling programs

that aim to develop integrated conceptual designs of plant

that synergistically combines supercritical cycles of pow-

er plants with chemical production benefit from use of

today’s computational tools such as CFD calculations,

flowsheet simulators and mathematical programming tech-

niques such as Mixed Integer (Non) Linear Programming

as elaborated by Baliban [3]. The economics of the integrat-

ed concept is far more favorable than any of its stand-alone

components. Such power plants not only provide feedstock,

raw material and catalyst, but can utilize the resulting

clean fuels and incorporate sequestering. The proposed

integrated facilities do also share environmental and gas

treatment facilitates. The approaches taken do need to

incorporate life cycle consideration and environmental

impact.

REFERENCES

[1] A. K. Sunol, Supercritical Extraction of Coal, PhD Dissertation, 1982.

[2] G. V. Despande, G.D. Holder, A. A. Bishop, J. Gopal, I. Wender, Ex-

traction of Coal with Supercritical Water, Fuel, 63(7) (1984) 956-960.

[3] R. C. Baliban, J. A. Elia, C. A. Floudas, Optimization framework for the

simultaneous process synthesis, heat and power integration of a ther-

mochemical hybrid biomass, coal, and natural gas facility, Computers

& Chemical Engineering, 35(9) (2011) 1647-1690.

SUPERCRITICAL wATER GASIFICATION AND ITS DEVELOPMENTS IN ChINA

203

SUPERCRITICAL wATER GASIFICATION AND ITS DEVELOPMENTS IN ChINA

Liejin guoState Key Lab of Multiphase Flow in Power Engineering (SKLMF),

Xi’an Jiaotong University (XJTU); Xianning West Road 28# Xi’an, Sha’anxi,710049, The People’s Republic of China;


Supercritical water provides an excellent reaction medium

for clean and efficient way in energy conversion. Since

1997, a series of studies on hydrogen production from su-

percritical water gasification have been conducted by the

group of State Key Lab of Multiphase Flow in Power En-

gineering (SKLMF) in Xi’an Jiaotong University (XJTU).

ThEORETICAL RESULTS

Chemical reaction equilibrium analysis is investi-

gated by Gibbs free energy minimization method. The

simulation result confirms the experimental result that as

reaction temperature increases, the hydrogen yield increas-

es. However, as the temperature is above about 600 ºC,

the gas yield is almost constant. That is to say, 600 ºC is

enough and further increase of temperature is not neces-

sary. As for the solar cavity-receiver, the exergy peaks at

about 600 ºC considering the heat loss from the solar

cavity-receiver. So, it sounds a good idea to couple super-

critical water gasification with solar concentrating system.

Separating CO2 is the basic for the CO

2 emission reduction.

High pressure separator is used for separating carbon di-

oxide with other gaseous products. According to phase

equilibrium analysis, the optimal operating condition for


CO2 capture is obtained. The study on gasification kinetics

model was proposed and it focuses on the main gaseous

products. CFD model is developed for the reactor optimi-

zation and amplification. The above achievement will be

published later. A novel thermodynamics cycle power gen-

eration system is proposed by SKLMP which is based on

coal gasification in supercritical water and multi-staged

steam turbine reheated by hydrogen combustion. It is char-

acterized by its high coal-electricity efficiency, net CO2

emission and no pollutants.

ExPERIMENTAL DEVICE

A quartz tube reaction system with the reactor di-

ameter of 1.5 mm and length of 200 mm was established

to obtain the non-catalytic reaction kinetics. High through-

put autoclaves made of Hastelloy C276 and Inconel 625

were established for the catalyst screening and the reac-

tion mechanism study. A continuous pipe-flow system for

supercritical water gasification was designed for the tem-

perature up to 800 ºC and the pressure up to 30 MPa. A

supercritical water fluidized bed system was developed

to solve the blocking problem and it was designed for the

temperature up to 923 K and the pressure up to 30 MPa.

It is proved from the point of view of thermal dynamics

that supercritical water gasification process driven by con-

centrating solar energy may achieve high efficiency for

hydrogen production. So the first supercritical water gas-

ification device driven by concentrated solar energy was

constructed. Hydrodynamics of a supercritical water flu-

idized bed was conducted and a predicting correlation for

the minimum fluidization velocity in a supercritical water

fluidized bed was obtained based on the experimental

results of a fixed bed and the fluidized bed pressure drop.


ExPERIMENTAL REGULARITy

The feedstock covers various agricultural biomass

(such as corn cob), liquid waste (such as black liquor, phar-

maceutical wastewater), solid wastes (such as municipal

sludge), coal (Yimin lignite, Hongliulin bituminous etc.)

and their model compound. The complete gasification op-

eration condition for each feedstock is obtained. Higher

temperature and oxidative equivalent ratio favors com-

plete gasification. Lignite has highest hydrogen fraction

and yield. Hydrogen gasification efficiency can be as high

as more than two hundred percent. It means that the hy-

drogen we obtained is two times higher than the hydrogen

originally in the coal. The influence of pressure is not sig-

nificant in the experimental scale we investigated; low

concentration favors complete gasification; particles more

than 100 µm needs on more grinding. The co-gasification

characteristics are investigated and Synergistic effect is

found. Organic wastes water can be used as the feedstock

of water-coal slurry. So hydrogen production can be com-

bined with waste treatment. Corrosion is an inevitable

topic for supercritical water gasification. Intergranular cor-

rosion may occur in the reactor inner wall, which can be

restrained by controlling the reaction condition or conduct-

ing corrosion protection treatment such as aluminizing.

CATALyST SCREENING

The catalytic effect of K2CO3 and Raney-Ni was

investigated for gasification in supercritical water. It is

proved that in pipe flow reactor K2CO3 has better catalyt-

ic effect due to the better dispersion. We also conducted

the study of catalyst screening, for the active with high

hydrothermal stability and strong carbon deposition re-

sistance in the process of supercritical water gasification.

Nickel -Magnesium -Al catalyst has been proved to be a

promising catalyst for supercritical water gasification.


DEMONSTRATION PLANT

Based on the experimental regular and theoretical

result mentioned above, a demonstration plant is estab-

lished in the Ningxia Hui Autonomous Region. The slurry

treatment is more than 1 ton per hour, and the maximal

concentrating power is 163 kW. The demonstration plant

verifies the feasibility of large-scale application of the tech-

nology. The details for the demonstration plant will be

published later. The demonstration plant paves the way

for the industrial application of supercritical water gasifi-

cation and it shows bright future of large-scale application.

ENzyME TREATMENT AND INACTIVATION OF MICROORGANISMS IN COMPRESSED FLUID MEDIA

207

ENzyME TREATMENT AND INACTIVATION OF MICROORGANISMS IN COMPRESSED FLUID MEDIA

José vladimir de oliveiraDepartment of Chemical and Food Engineering,

Federal University of Santa Catarina (UFSC), EQA/CTC; CP 476 – Trindade, 88040-900, Florianópolis, SC, Brazil;


This talk comprises a brief review of the state of the art

regarding enzyme treatment in compressed fluids towards

its utilization in enzyme-catalyzed reactions of great in-

terest for chemical and food industries. In particular, great

attention is devoted to oil modification, as well as produc-

tion of GOS and FOS using supercritical carbon dioxide,

propane, n-butane and liquefied petroleum (LPG) gas as

solvent media. Enzyme behavior in compressed fluid me-

dium is discussed in terms of the effects of system pressure

and temperature, exposure time and depressurization rate.

The behavior of free, immobilized and enzyme in solution

are investigated in compressed fluid medium and charac-

terized by several analytical techniques (SEM, XRD, FTIR,

DSC, TGA, etc.). A variety of high-pressure equipment is

shown to be useful for enzyme treatment experiments,

depending on the enzyme form, varying the temperature

from 35 to 75 ºC, in the pressure range of 10-280 bar, expo-

sure times from 1 to 6 hand adopting distinct decompres-

sion rates (compression/expansion cycles). Results showed

that, in general, activity losses are verified for all enzymes

in carbon dioxide, while the use of propane, n-butane and

LPG promoted enhancements of enzyme activity and sta-

bility. In general, within the range studied, temperature


and exposure times affected positively enzyme activity

while the decompression rates did not demonstrate to be

a relevant variable. Additionally, the use of supercritical

carbon dioxide (scCO2) treatment as an innovative pres-

ervation method to inactivate pathogenic microorganisms

in food products is considered. The effects of scCO2 treat-

ment on the inactivation of Escherichia coli, Listeria mono-

cytogenes and the microbial load of Vibrio parahaemolyticus

in fresh oysters are considered. The effects of exposure

time, scCO2/product mass ratio, temperature, number of

pressure cycles, system pressures from 80 bar up to 200

bar and also pressurization and depressurization rates on

the microbial inactivation is taking into account. A storage

study is also carried out on the treated and untreated prod-

uct to monitor microbial growth. It is shown that treatment

with scCO2 may be a potential technique to reduce micro-

bial growth, which may lead to product’s safety enhance-

ment with possibly increasing shelf life.

REACTOR DESIGN IN SUPERCRITICAL CONTINUOUS FLOW SySTEMS

209

REACTOR DESIGN IN SUPERCRITICAL CONTINUOUS FLOW SySTEMS

Thomas huddleUniversity of Nottingham;

University Park, NG7 2RD, Nottingham, Nottinghamshire, UK; E-mail: [email protected]

This presentation addresses the design of supercritical

continuous flow systems, which can be applied to a large

number of processes, but focuses mainly on their applica-

tion to hydrothermal and solvothermal synthesis of metal

and metal oxide nanoparticles. Continuous flow systems

offer several advantages over traditional batch methods,

and supercritical fluid processing is no exception. On larg-

er scales, continuous flow systems can offer higher through-

put, while minimising the volume of fluid subject to the

often extreme reaction conditions at any one time. A ma-

jor benefit of working with continuous flow systems at an

analytical scale is the ability to rapidly screen a large range

of reaction conditions, which is generally not possible when

working in batch. Several system components are neces-

sitated in supercritical continuous flow designs, but un-

doubtedly the most important feature is the reactor — the

volume in which the desired process occurs. There are

several important considerations related to reactor design

in continuous flow systems, especially with regard to res-

idence time. Residence time (time the flow experiences

reaction conditions) is critical in relation to the activation

energies for a process, and is affected by distribution in

flow paths, stagnant zones, and the rates of heating and

cooling; these are factors which are themselves dependent


on mixing geometries, turbulence and other effects of the

flow dynamics.

Reactor design is also important when concerning

processes that are liable to form solids, either inherently

(e.g. nanoparticle synthesis), or undesirably (such as char

formation). Small constrictions within reactors or flow sys-

tems may present potential regions for blockage formation,

or allow for accumulation of solids, which may later con-

taminate the product stream. In the case of hydrothermal

metal oxide nanoparticle formation, an ambient tempera-

ture metal salt precursor stream is mixed with a super-

heated water stream. The rapid drop in solubility of the

metal salt at the mixing point allows for a high degree of

supersaturation, which effectively reduces the critical nu-

cleation size, thus driving nanoparticle formation. This

process of mixing the precursor with a preheated stream

may be applied to almost any continuous flow process,

and offers the ability to reach the desired reaction condi-

tions virtually instantly; this can be a very useful technique

for studying kinetics. The process of mixing an ambient

temperature and superheated stream is not straightfor-

ward due to the large differences in density and viscosity.

Traditional mixing geometries such as T-pieces and Y-piec-

es produce poor mixing, with back-mixing and flow strat-

ification often observed. Innovative reactor designs such

as contraflow mixers are able to exploit the differences in

density to achieve highly turbulent mixing, and to minimise

recycling and stagnant zones. A pseudo fluid method is

described as a technique for visualising mixing regimes

within various reactor configurations under different con-

ditions. In this process, ambient temperature water is rep-

resented by aqueous sucrose solution and supercritical

water is represented using methanol. These fluids possess

similar density and viscosity ratios to those between am-


bient temperature water and supercritical water. By ad-

justment of the flow rates and pseudo reactor dimensions,

similar Reynolds and Grashoff numbers can be achieved

to those experienced in reactors under supercritical con-

ditions. This technique allows quantification of mixing

efficiency, as well as visualisation of issues such as flow

recycling, stagnant zones, and other inconsistencies in

the mixing dynamics. For a more genuine representation

of flow path distributions within supercritical continuous

flow systems, a technique involving injection and UV de-

tection of chromophoric tracers is discussed. Using this

method, residence time distributions can be compared

between reactors, and the effect of stagnant zones at var-

ious points of the continuous flow system may be assessed.

Such data provides useful experimental validation of CFD

simulations for reactors. Other reactor geometries will also

be assessed using these techniques, such as those involv-

ing concurrent mixing and others which feature multiple

precursor stream inlets; the pros and cons of each will be

discussed and contrasted to contraflow mixing.

ACOUSTIC wAVE GENERATION IN NEAR-CRITICAL SUPERCRITICAL FLUIDS: EFFECTS ON MASS TRANSFER AND ExTRACTION

213

ACOUSTIC wAVE GENERATION IN NEAR-CRITICAL SUPERCRITICAL FLUIDS: EFFECTS ON MASS TRANSFER AND ExTRACTION

Bakhtier farouk, nusair hasanDepartment of Mechanical Engineering and Mechanics,

Drexel University; Philadelphia, PA 19104, USA

Supercritical fluid extraction (SFE) is a technique that adds

a supercritical fluid of an extraction medium to a sample

containing a constituent targeted for extraction. Extraction

by means of supercritical fluid can be expected to improve

efficiency, including shorter extraction times and simpli-

fied procedures when compared with extraction techniques

that employ organic solvents. Use of supercritical carbon

dioxide has received recent attention as an environmen-

tally friendly extraction technique that does not use haz-

ardous organic solvents, as has been advocated by the

green chemistry movement in recent years. The conven-

tional process of extracting solutes from a solid matrix

(packed bed) using supercritical solvents has a very slow

dynamics even when solute free solvent is re-circulated

and therefore improvements in the extraction process are

required. The use of acoustic waves represents a potential

effective method of enhancing mass transfer (extraction

and separation) processes with supercritical fluids. Recent

results of mass transfer enhancement by using resonant

acoustic waves will be presented. Acoustically augment-

ed flow and transport in supercritical carbon dioxide gen-

erated by standing wave in a cylindrical enclosure was

simulated. The oscillatory flow field in the enclosure is

created by the vibration of one of the end walls of the


enclosure. The geometric parameters and the frequency

of the vibrating wall are chosen such that the lowest

acoustic mode propagates along the enclosure. A real-fluid

model for representing the thermo-physical and transport

properties of the supercritical fluid is considered. The ful-

ly compressible form of the Navier-Stokes equations is

used to model the flow fields and an implicit time-march-

ing scheme is used to solve the equations. The formation

of the acoustic field in the enclosure is computed and ful-

ly described and the acoustic boundary layer development

is predicted. The interaction of the wave field with viscous

effects and the formation of streaming structures are re-

vealed by time-averaging the solutions over a given period.

Due to diverging thermo-physical properties of supercrit-

ical fluid near the critical point, large scale oscillations

are generated even for small sound field intensity. The

effects of near-critical property variations and system pres-

sure on the formation process of the streaming structures

are also investigated. Application of the acoustically aug-

mented flow in extraction of caffeine from coffee beans

using supercritical carbon dioxide is demonstrated numer-

ically. The predicted results confirm that acoustic waves

significantly accelerate the kinetics of the supercritical

extraction process, especially in the near-critical region

of operation and improve the final extraction yield.

PANEL PRESENTATIONS

Panel V: Process Technology and Future Direction

DEVELOPING AN INTEGRATED SUPERCRITICAL FLUID BIOREFINERy FOR ThE PROCESSING OF GRAINS

217

DEVELOPING AN INTEGRATED SUPERCRITICAL FLUID BIOREFINERy FOR ThE PROCESSING OF GRAINS

feral Temelli, ozan nazim ciftciDepartment of Agricultral, Food and Nutiritonal Science,

University of Alberta; 4-10 Agr/For Centre, T6G2P5, Edmonton, Alberta, Canada;

E-mail: [email protected], [email protected]

Limited supply of petroleum resources together with the

ever increasing demand for petroleum-based products has

fueled the emergence of the bioeconomy. Global trends

highlight the growth in fuel, energy, materials, chemicals

and other products based on renewable feedstocks as eco-

nomically viable alternatives to petroleum-based products.

This has led to the “biorefinery” concept of processing

renewable feedstocks similar to that in a conventional oil

refinery and petro-chemical complex, where crude oil is

separated into various fractions and with further processing

converted into a vast array of products. Thus, a biorefinery

would integrate a variety of separation and conversion

processes to produce multiple product streams from renew-

able feedstocks. Industrial-scale integrated biorefineries

are critical for the growth of a sustainable bioeconomy.

Grains of cereals and oilseeds are a promising source of

renewable feedstock for biorefineries. Grains are composed

of lipids, proteins, carbohydrates as well as moisture, ash

and other minor components. Most of the conventional

processes result in underutilization of the grains by focus-

ing on only one or a limited number of components of the

grains; therefore, the full value of grains is underestimat-

ed. In an integrated biorefinery, the first major stage would


focus on the separation processes to fractionate the major

and minor components of the grains. Then, in the second

stage, these fractions would be converted to other high

value ingredients/intermediates/products through various

conversion processes. Finally, application development is

critical for these ingredients/intermediates to be utilized

in a variety of end uses, depending on their functionality,

targeting food, nutraceutical, pharmaceutical, cosmetic,

biofuel, biochemical, biomaterial and other industries. In

addition to some of the conventional separation and con-

version technologies, supercritical fluid technology has a

major role to play in developing such an integrated biore-

finery, considering the well-known advantages of supercrit-

ical carbon dioxide (scCO2). Among the major components

of lipids, proteins and carbohydrates, scCO2 can selective-

ly extract lipids, more specifically neutral lipids and lipid-

soluble minor components, such as tocopherols, carotenoids

and phytosterols. The residual proteins and carbohydrates

would be of high quality and functionality as opposed to

the case when petroleum-based solvents are used for lip-

id extraction. For example, canola proteins had better qual-

ity when lipids were extracted with scCO2 compared to

those obtained after hexane extraction. The residual pro-

tein/carbohydrate mixture can be further fractionated us-

ing alkali extraction and/or subcritical water extraction

technology. The crude lipids extracted by scCO2 can be

fractionated to isolate the high-value minor lipid compo-

nents. The neutral lipids, specifically triglycerides, can be

used as is or can be converted to other valuable compo-

nents through enzymatic or non-enzymatic reactions in

scCO2 media. For example, triglycerides solubilized in scCO

2

can be converted to biodiesel through lipase-catalyzed

transesterification with methanol or ethanol to form fatty

acid methyl or ethyl esters, respectively. Minor lipid com-

PANEL V: PROCESS TEChNOLOGy AND FUTURE DIRECTION 219

ponents can be encapsulated via various particle forma-

tion techniques, where the protein or carbohydrate fractions

can be used as the coating material to form novel delivery

systems for these bioactive components. All of the above

scCO2-based unit operations have been demonstrated for

various grains of cereals and oilseeds, rich in lipids. Over

the past three decades, the know-how has progressed sub-

stantially towards integration of these unit operations to

develop a biorefinery. However, there are challenges in

terms of the large scale equipment and operations expect-

ed of biorefineries to be able to compete with the petro-

leum-based refineries. Therefore, it is critical to integrate

the recovery of low-volume but high-value ingredients for

favorable process economics. As well, defining the optimal

scale of operation is essential to achieve economies of scale.

Construction of continuous scCO2 extraction units to re-

place the commonly used semi-continuous systems in

operation today is essential to handle the large volumes

of grains as feedstock. Feedstock diversity, including lo-

cation and year-to-year variability, is another challenge

for process optimization. This can be overcome by strate-

gic location of biorefineries, targeting optimization of op-

erations for the grain specific to that region. Environment

friendly aspect of scCO2-based biorefineries may ease the

protocols of acquiring regulatory permits. Building part-

nerships with conventional industries that produce large

quantities of CO2 can be a win-win situation to reduce

greenhouse gas emissions. On the other hand, consumer

education on the advantages of scCO2 technology is im-

portant to grow the demand for products of such a green

technology, which in turn will force the industry to adopt

supercritical fluid technology to a greater extent. The po-

tential for employing scCO2 technology in an integrated

biorefinery is just starting to be realized and offers prom-


ise for cost-effective and environmentally friendly process-

ing of the grains to produce ingredients/products for food,

nutraceutical, pharmaceutical, cosmetic, fuel, chemical

and materials applications. Complete utilization of all the

grain components in such a biorefinery will also reduce

the food vs. fuel competition. It will also help meet the

growing consumer demand for “natural” products pro-

cessed with green technologies. scCO2-based biorefineries

may play a key role in moving towards a sustainable bio-

economy via process intensification, by reducing energy

requirements and waste streams, and increasing process

efficiency while providing a range of food and non-food

ingredients/products.

PROCESSING OF OLIGOMERIC SySTEMS VIA SCE FOR ENERGy AND MATERIALS APPLICATIONS

221

PROCESSING OF OLIGOMERIC SySTEMS VIA SCE FOR ENERGy AND MATERIALS APPLICATIONS

David f. Esguerra, Julian velez, Adam scott, Mark c. Thies

Dept. of Chemical and Biomolecular Engineering, Clemson University;

29634-0909, Clemson, SC, USA; E-mail: [email protected]

CARBONACEOUS PITChES AND OLIGOMERS

Carbonaceous oligomeric pitches can be used as

precursors for a variety of high-performance carbon ma-

terials for energy and materials applications, including

cathodes for lithium ion batteries, high thermal conduc-

tivity carbon fibers, and carbon-based composites. These

oligomeric materials can be produced from a variety of

resources, including coal tar, petroleum by-products, and

pure polycyclic aromatic hydrocarbons (PAHs), using ei-

ther thermal or catalytic polymerization processes.

A long-term goal of our group is to understand how

the oligomeric composition of carbonaceous pitches af-

fects their bulk properties. In previous work with pitches

derived via thermal polymerization from the petroleum

by-product decant oil, Thies and co-workers showed how

supercritical extraction (SCE; also called dense-gas ex-

traction, or DGE) could be used to isolate these petroleum

pitches into their respective oligomers. The oligomeric frac-

tions were then available for analysis using both conven-

tional and advanced characterization techniques. Examples

of information obtained therefrom included definitive mo-

lecular structures for the dimers of petroleum pitch, soft-


ening points of dimer cuts, and the discovery of liquid

crystallinity in trimer cuts.

The goal of this study is to fractionate via SCE a

carbonaceous pitch produced via the catalytic polymer-

ization of the PAH monomer pyrene into its constituent

oligomers. Isolating the oligomers of pyrene pitch would,

for the first time, provide information about the oligomer-

ic content of a pitch produced catalytically from pure PAHs.

The use of both neat toluene (Tc = 318.6 °C; Pc = 41.1

bar) as the SC solvent, and the addition of N-methyl-2-

pyrrolidone (NMP; Tc = 450.94 °C; Pc = 47.2 bar) as a

co-solvent, is being explored.

Previous work on the fractionation of carbonaceous

pitches (typically carried out prior to an analytical char-

acterization step) has been limited primarily to (a) solvent

extraction methods, such as sequential Soxhlet extraction

with the solvents benzene, pyridine, and quinoline, and

(b) the simple separation of the pitch into solvent-soluble

and insoluble fractions. However, as has been shown by

Edwards and Thies, conventional solvent extraction meth-

ods produce fractions that are still quite broad in their

molecular weight distribution (MWD). Thus, in the above-

mentioned previous work, no information about the pre-

ponderance of the various oligomers in the original pitch

was reported, and the focus was on presenting average

properties for pitch fractions isolated, versus definitive

molecular structures.

LIGNIN FROM BIOMASS By-PRODUCT STREAMS

Another poorly defined oligomeric system for which

supercritical fluid processing can provide unique advan-

tages is the biopolymer lignin. Lignin is one of the most

common organic compounds on earth, comprising about

30% of all organic carbon. Only cellulose is more abundant.


In a pulp and paper mill, the pulping process is used to

dissolve away the lignin fractions of wood, liberating the

cellulosic fibers from the wood matrix in the form of a pulp

that is then used to make paper. This chemical digestion

of the lignocellulosics in wood is accomplished through

various pulping processes (with the kraft sulfate process

being globally dominant), and the lignin ends up in a

by-product stream known as “black liquor”. Typically, this

black-liquor stream is burned in the recovery furnace of

the paper mill for its fuel value and to recover the inorganic

ash that is returned to the pulping process.

If the high-ash (~50 wt%) lignin in this black liquor

could be isolated in a dry, low-ash (0.5-2.0 wt%) state, the

result would be an excellent-quality, low-cost biofuel with

essentially the same energy content as coal and about

50% more energy than low-moisture wood pellets. Taken

yet another step, if the lignin could be recovered in the

“ultrapure” state, in particular with a low metals content

and a controllable molecular weight, it would be much

more than a fuel — it would be a high-value, renewable

biopolymer. Such an ultrapure lignin would have a wide

range of uses because lignin is unique among abundant

biopolymers in having aromaticity. For example, research-

ers have suggested that an ultrapure lignin could be used

as the oligomeric feedstock for manufacturing low-cost

carbon fibers, which could then be used for automotive

structural applications. The result would be dramatic re-

ductions in the weight of the U.S. vehicle fleet — and con-

current increases in fuel mileage.

In summary, lignin separated from Kraft black li-

quor has the potential to become an inexpensive and re-

newable platform for the production of aromatic chemicals,

bio-based materials, and clean biofuels. However, the het-

erogeneity of lignin presents a challenge for obtaining a


more fundamental understanding of the chemical struc-

ture of this material. This is where supercritical fluids can

play a role. The fractionation of lignin via SCE processing

has two potential benefits: (1) chemical structure-vs.-bulk

property relationships can be obtained, and (2) the frac-

tions themselves can have properties useful for various

applications.

SUPERCRITICAL TEChNOLOGy APPLIED TO FOOD PROCESSING

225

SUPERCRITICAL TEChNOLOGy APPLIED TO FOOD PROCESSING

Julian MartínezLASEFI/DEA/FEA (School of Food Engineering),

UNICAMP (University of Campinas); R. Monteiro Lobato, 80, 13083-862, Campinas, SP, Brazil;


Some solvents at high pressures are used as alternatives

to liquid organic compounds in industrial processes, due to

their lower toxicity, adequation to environmental exigen-

cies, easy separation, and possibility of using moderate

temperatures. In the food industry, carbon dioxide (CO2)

is the most applied solvent, due to its non-toxicity. At high

pressures, generally at the supercritical state, CO2 has

been used as extraction solvent for coffee decaffeination,

production of hop extracts and volatile oils used as con-

diments. In the research field, many groups have been

working with supercritical CO2 extraction from novel sourc-

es, to obtain condiments, aromas and compounds with

high nutritional or medicinal value. In food engineering

the raw materials for extraction may be native plants or

even wastes from the food industry, which often contain

valuable compounds.

As well as SFE, extraction with pressurized liquids

(PLE) appeared as an alternative to extraction and frac-

tionation of natural products, since it is a clean technolo-

gy that allows controlling process parameters to tune the

selectivity for a specific group of compounds, which is a

feasible way to aggregate value to natural extracts. Water

as a PLE solvent is non-toxic, non-flammable, cheap and

environmentally safe. Indeed, PLE allows fast extraction


in closed and inert systems at high pressure and moderate

temperatures. Another advantage of PLE is that, at high

pressures, solvents remain liquid at temperatures above

their boiling point, where the solubility of some compounds

may be enhanced. Of course, in this case the target com-

pounds cannot be sensible to high temperatures. There-

fore, PLE using water as solvent may be complementary

to SFE with CO2, since the polar nature of water allows

extracting compounds that would be insoluble in CO2. In

this sense, one can use both techniques as sequential

steps of a unique process, to obtain products with different

properties from the same raw material.

Ultrasound is used to increase the efficiency of ex-

traction, since it reduces the required temperature and

favors the dissolution of target compounds in the chosen

solvent. Ultrasonic waves cause expansion and compres-

sion of bubbles in the solvent, which may collapse and

lead to cavitation. Near natural raw materials, cavitation

can result in rupture of cell walls, allowing the penetration

of the solvent inside the cells, and thus enhancing mass

transfer. In SFE, ultrasound can promote desorption of

extractable material from the sold surfaces. Therefore, the

application of ultrasound during extraction with liquid or

supercritical solvents can increase the yield and velocity

of the process.

Bioactive compounds can be highly sensible to heat,

light, oxygen or other adverse conditions. Moreover, the

functionality of such compounds may be favored when

they are gradually liberated into the organism. This is,

mainly, the case of pharmaceutics, but it can also be ap-

plied to food ingredients. In this context, mechanisms to

protect the compounds from adverse conditions and make

possible their controlled liberation are needed. Encapsu-

lation, through formation of micro or nanoparticles with

polymeric matrices, is a known strategy to obtain such


results. Methods for particle formation using supercritical

fluids have been explored as alternatives to consolidated

techniques, such as spray-drying, fluidization or freeze-dry-

ing, and their results are promising. Among these tech-

niques, some use the supercritical fluids as antisolvent,

i.e., the supercritical fluid is used to remove a liquid solvent

from a mixture, leading to the precipitation of particles

inside the polymer. Two techniques can be highlighted in

this context: Supercritical Antisolvent (SAS) Precipitation

and Supercritical Fluid Extraction of Emulsions (SFEE).

The advantages of supercritical technology for particle

formation are the reduced need of handling materials that

allows enhancing yield, easy equipment cleaning, and

therefore, increased viability for scale-up, besides the pos-

sibility of operating in continuous mode.

In the SAS process a liquid solution containing the

target compound or product is brought to contact with a

supercritical fluid. As a result, the liquid is saturated with

the supercritical fluid, leading to the precipitation of the

product. A polymer can act as encapsulation agent in this

process, resulting in the formation of particles of the prod-

uct involved or spread in the polymer. This technique has

been studied for the precipitation of pharmaceuticals and

bioactive compounds present in food, such as carotenoids.

The main disadvantage of the SAS process, as well

as of other precipitation techniques using supercritical

fluids, is the control of particle size. It is difficult to obtain

particles below micrometric scale, and particle agglom-

eration in frequent. The SFEE process may solve these

problems, because in this case the precipitation occurs

from droplets of an emulsion, where the target product is

in the disperse phase. The supercritical fluid extracts the

solvent from this phase, leading to the precipitation of the

target compound with the polymer, and the particles re-

main suspended on the aqueous phase. Thus, the particle


size can be monitored through the size of the emulsion

droplets. Due to the nature of the process, SFEE is recom-

mended to produce particles of compounds not soluble or

poorly soluble in water, such as carotenoids, oils, and oth-

er compounds with application in food.

Finally, supercritical fluids can be reaction means

in the synthesis of various products, as biofuels, and in

the food industry, terpenic esters with flavor properties

and sugar esters that can be applied as emulsifiers in pro-

cessed food formulations. In these processes, immobilized

enzymes catalyze reactions in supercritical CO2. Theoret-

ical and practical works indicate that lipases are efficient

in such processes, and can be used in various reaction cy-

cles. As well as in SFE, the separation of the reaction prod-

ucts and the solvent can be achieved by pressure reduction.

Therefore, supercritical fluids can replace toxic organic

solvents that are typically employed as reaction means in

the industry.

Our research group has been concentrating its works

on the mentioned techniques, with emphasis in products

from natural sources with applicability in food pro cessing

and products. As examples, researches are being con-

ducted on the following processes: SFE from red pepper,

assisted or not by ultrasound, to obtain extracts with cap-

saicin, and further encapsulation of the extracts with SAS

or SFEE; recovery of anthocyanins and other phenolics

from blueberry and blackberry wastes, for subsequent par-

ticle formation by SAS; extraction and encapsulation of

bioactive compounds from passion fruit residues; and en-

zymatic synthesis of terpenic esters on supercritical CO2

to produce food flavors. Nine master and PhD students are

involved in such works, and the process units are devel-

oped in our laboratory. The possibility of coupling different

processes with supercritical fluids, or even to other clean

technologies should be studied in future works of our group.

ANALySIS OF SAVING OF ORGANIC SOLVENTS IN ThE RECOVERy OF ANTIOxIDANTS FROM VEGETAL SOURCES By SFE

229

ANALySIS OF SAVING OF ORGANIC SOLVENTS IN ThE RECOVERy OF ANTIOxIDANTS FROM VEGETAL SOURCES By SFE

Tiziana fornariInstituto de Investigación en Ciencias de la Alimentación,

CIAL (CSIC-UAM); C/Nicolás Cabrera 9, Campus de Cantoblanco, 28049 Madrid, Spain;


The processing of vegetal materials to recover phytochem-

icals with biological activity is currently an interesting

matter of new markets. Supercritical fluid extraction (SFE)

with carbon dioxide (CO2) is a competitive technology in

this field, being one of the “Top Ten List” of CO2-SFE ben-

efits the advantage of recovering the extract with high

purity, completely free of solvent. Since no organic solvents

are employed, subsequent processing for its elimination

and recycling is not required. However, it is well known

that the consumption of organic solvents in SFE not al-

ways can be circumvented. In fact, the supercritical CO2

extraction of polar or even moderate polar compounds gen-

erally requires the use of an adequate cosolvent to enhance

yield and to design processes with acceptable economic

profit. Hundreds of examples can be given in which the

addition of a small amount of cosolvent (ethanol, aceto-

nitrile, ethyl acetate, among others) produce considerably

increases of extraction yield and recovery of target com-

pounds. Among these target compounds a number of po-

lar antioxidants, such as flavonoids and phenolic acids,

require the use of cosolvents to attain their SFE from veg-

etal matter [1]. But even in the case of moderate polar

antioxidants the use of small amounts of an acyl alcohol


as cosolvent of CO2 considerably increase the extraction

yield. In these cases, the most frequently proposed cosol-

vent is ethanol since its traces in the final product is

permitted in food, nutraceutical or pharmaceutical appli-

cations. For example, it is well known that the solubility

of several phenolics, including gallic acid, catechins, res-

veratrol, quercetin and salicylic acid, in CO2 containing

small amounts of methanol or ethanol is considerable

higher in comparison with their solubility in pure CO2 [2].

Thus, a remarkable increase in the recovery of these sub-

stances is observed if alcohol cosolvents are included in

the supercritical CO2 extraction process [3]. Another ex-

ample is the recovery of carnosic acid, a moderate polar

lipophilic phenolic diterpene present in rosemary leaves.

It has been reported that the addition of 5-10% ethanol as

CO2 cosolvent can duplicate extraction yield, producing a

4-7 fold increase of this antioxidant in the extract, while

a minor effect on the recovery of essential oil constituents

was observed [4]. Despite the benefits that the use of a

cosolvent can produce in particular applications, when

a cosolvent is employed the most outstanding advantage

of SFE in comparison with solvent-based technologies

seems to be somewhat lost. Thus, other extraction alter-

natives such as ultrasound assisted extraction (UAE) or

pressurized liquid extraction (PLE) appear as competitive,

because both are much more effective regarding organic

solvent consumption in comparison with traditional solid-

liquid extraction (SLE). The point is to assess the efficien-

cy in terms of solvent consumption vs. recovery of target

phytochemicals, which can be a decisive matter of analy-

sis when selecting the extraction technology to be applied

in a particular case. As a case of illustration, it can be

mentioned the extraction of carnosic acid from the same

lot of rosemary leaves (45 mg carnosic acid per g of dry


matter) using different techniques. Quite different results

are obtained if the amount of antioxidant extracted was

referred to the amount of liquid solvent employed. All SLE,

UAE, PLE and SFE produced good recovery of carnosic

acid (higher than 60%) under appropriate extraction con-

ditions. Nevertheless, the consumption of ethanol is very

different, when considering the mg of carnosic acid ex-

tracted per mL of ethanol consumed. UAE and PLE require

one-fifth of the solvent employed in SLE to produce even

somewhat higher recoveries. But, in comparison with the

supercritical extraction (assisted or not with ultrasound)

the increase of carnosic acid recovery per mL of ethanol

employed is noteworthy (7-10 times higher). A comparison

of the efficiency of using organic solvents in the recovery

of antioxidants from several different plant matrixes and

using different technologies will be presented and dis-

cussed. Antioxidants such as phenolic diterpenes, triterp-

enic acids and carotenoids will be considered, and examples

of SLE, UAE, PLE, and SFE with pure CO2 and assisted

with ethanol cosolvent will be pondered.

ACKNOWLEDGEMENTS

This work was financed by project ALIBIRD, S2009/AGR-1469 (Comunidad

de Madrid, Spain).

REFERENCES

[1] E. Reverchon, I. De Marco, Supercritical fluid extraction and fraction-

ation of natural matter, J. Supercritical Fluids, 38 (2006) 146-166.

[2] R. B. Gupta, J-J Shim, Solubility in supercritical carbon dioxide, CRC

Press, Taylor and Francis Group (2007).

[3] M. T. Tena, A. Ríos, M. Valcárcel, Supercritical fluid extraction of

t-resveratrol and other phenolics from a spiked solid Fresenius, J.

Analytical Chemistry, 361 (1998) 143-148.

[4] T. Fornari, G. Vicente, E. Vázquez, M. R. García-Risco, G. Reglero, Iso-

lation of essential oil from different plants and herbs by supercritical

fluid extraction, J. Chromatography A, 1250 (2012) 34-48.

ThE PRODUCTION OF FERMENTABLE SUGARS By ThE SUBCRITICAL WATER hyDROLySIS OF FOOD INDUSTRy RESIDUES

233

ThE PRODUCTION OF FERMENTABLE SUGARS By ThE SUBCRITICAL WATER hyDROLySIS OF FOOD INDUSTRy RESIDUES

Juliana M. pradoCTBE (Brazilian Bioethanol Science and Technology Laboratory) /

CNPEM (Integrate Brazilian Center of Research in Energy and Materials); R. Giuseppe Máximo Scolfaro, 10.000, 13083-970, Campinas, SP, Brazil

Tania forster-carneiro, M. Angela A. MeirelesLASEFI/DEA/FEA (School of Food Engineering),



Bioethanol has been investigated as a potential alterna-

tive to liquid fossil fuels due to its eco-friendly character-

istics and relatively low production cost. First-generation

bioethanol is produced today from raw materials that are

rich in simple sugars or starch, such as sugarcane and

corn. However, these crops are also food sources for both

humans and animals. To avoid the fuel versus food dilem-

ma, second-generation bioethanol aims to use non-edible

raw materials as the source of fermentable sugars. Ligno-

cellulosic residues from the food industry fulfill these re-

quirements because they are not used as food sources and

do not occupy farmable lands. The hemicellulosic and cel-

lulosic fractions of the biomass can be hydrolyzed into

fermentable sugars by several methods, using acid, alkali

or enzymatic catalysts. With increasing knowledge of the

processes that take place during the hydrolysis of biomass

come new techniques, which are being exploited to im-

prove the process. Sub/supercritical water hydrolysis (SWH)

has been demonstrated to have significant potential for

use as a highly efficient hydrolytic process with several


advantages over conventional processes, such as the lack

of need for pre-treatment, shorter reaction times, lower

corrosivity, lower residue generation, the lack of use of

toxic solvents and the reduced formation of degradation

products. However, further optimization of the operating

conditions (temperature, time, solvent:solid proportion) and

economic evaluations of the process are still needed so

that the technique can be scaled-up to the industrial level.

A semi-batch unit equipped with a 50-mL reaction vessel

that can operate up to 400 °C and 400 bar, with the possi-

ble addition of CO2 as an acid catalyst, was built. The unit

was used to perform the subcritical water hydrolysis of

sugarcane bagasse, pressed palm fiber, coconut husk and

defatted grape seeds at water flow rates of 10-55 mL/min,

temperatures of 200-300 °C, total processing times of 30-60

min and under 20 MPa of pressure. The results obtained

using pure water as the reaction medium were compared

with the results obtained using water + CO2 as the reac-

tion medium. Fractions of the hydrolysate were collected

every 2 min. The hydrolysates were analyzed for pH, total

reducing sugars, monosaccharides and degradation prod-

ucts. The maximum total reducing sugars recovered for

sugarcane bagasse was 23% at 214 °C and 55 mL/min

using pure water as the reaction medium. For pressed palm

fiber, coconut husk and defatted grape seeds, the maxi-

mum values of total reducing sugars obtained were 11.5%

(256 °C, with pure water), 14% (262 °C, with CO2), and 10%

(258 °C, with CO2), respectively. The total reducing sugars

recovered increased with temperature; however, for the

coconut husk and defatted grape seeds, the value only

increased with the addition of CO2. The total degradation

products increased with temperature, while the monosac-

charides remained approximately constant, which means

that more oligosaccharides were recovered at higher tem-


peratures, due to the increased efficiency in the break-

down of cellulose. Each raw material presented different

behaviors when subjected to the same operational condi-

tions. Therefore, each lignocellulosic biomass should be

individually studied for SWH. Nevertheless, SWH appears

to be a promising technology for the recovery of fermentable

sugars from lignocellulosic residues in the food industry.

ACKNOWLEDGEMENTS

J. M. Prado thanks FAPESP (2010/08684-8) for the postdoctoral fellowship.

The authors acknowledge funding from FAPESP and CNPq.

ThE INTEGRAL UTILIzATION OF BIOMASSES BASED ON SUB/SUPERCRITICAL FLUIDS: ENVIRONMENTAL, ENERGETIC AND ECONOMIC ASSESSMENTS OF TEChNOLOGICAL SCENARIOS

237

THE INTEGRAL UTILIZATION OF BIOMASSES BASED ON SUB/SUPERCRITICAL FLUIDS: ENVIRONMENTAL, ENERGETIC AND ECONOMIC ASSESSMENTS OF TECHNOLOGICAL SCENARIOS

Juliana Q. Albarelli, Adriano V. Ensinas, François Maréchal Industrial Energy Systems Laboratory (LENI),

Swiss Federal Institute of Technology Lausanne (EPFL); Station 9, CH-1015, Lausanne, Switzerland;



UNICAMP (University of Campinas);R. Monteiro Lobato, 80, 13083-862, Campinas, SP, Brazil

Second generation ethanol production has been an im-

portant line of research around the world. In the Brazilian

scenario, sugarcane bagasse is the main material inves-

tigated for the production of cellulosic ethanol. The con-

cept of integrating its production with the conventional

technique of ethanol production from sugarcane in a biore-

finery has been studied by different researchers. Experts

agree that future biorefineries should focus on the produc-

tion of high value products prior to biofuel and/or energy

production. In view of this and considering the remaining

obstacles for the establishment of a sugarcane biorefinery,

the sub/supercritical technology stands out. Because such

technology demands substantial energy consumption,

strat egies for energy consumption reduction must be de-

veloped in addition to process optimization. Currently, our

research group is contributing to this scientific and techno-

logic demand, comparing the sub/supercritical technology

with other potential technologies at a su garcane biorefin-

ery using simulation tools. Simulation tools play an impor-


tant role as decision-support tools that assist in designing

the infrastructure for cellulosic ethanol production and

sugarcane biorefineries. In this sense, the software ASPEN

PLUS and VALI have been used to evaluate the main pro-

cesses, including the supercritical extraction, supercritical

hydrolysis and supercritical gasification of sugarcane ba-

gasse. All of the processes analyzed are thermally integrat-

ed with the sugarcane biorefinery using Pinch Analysis.

The processes are analyzed in light of their economic and

environmental impacts, and multi-objective optimization

is performed using the software OSMOSE, developed by

LENISYSTEM/LENI/EPFL (Switzerland). In the near future,

this project will also evaluate different technology scenar-

ios developed mainly in LASEFI/DEA/FEA/UNICAMP that

aim to integrate the use of different biomasses using sub/

supercritical fluids at all stages. In this regard, future biore-

fineries based on the sequential acquisition of secondary

metabolites using supercritical ethanol and CO2, in addi-

tion to the subsequent fractionation of biomass using sub-

critical water and the production of monosaccharides from

cellulose-rich solid waste using supercritical water, will

be evaluated. Finally, the integration of the sugarcane and/

or microalgae biorefinery will be evaluated for the biore-

fineries studied, with the goal of obtaining energy efficien-

cy and the economic and environmental impacts, as well

as performing multi-objective optimization.

POLyMER FOAMING WITh SUPERCRITICAL CO2 — ChALLENGES IN BATCh-WISE AND CONTINUOUSLy OPERATED PROCESSES

239

POLyMER FOAMING WITh SUPERCRITICAL CO2 — ChALLENGES IN BATCh-WISE AND CONTINUOUSLy OPERATED PROCESSES

sulamith frerich, Marcus petermannRuhr-University Bochum;

Universtitaetsstr. 150, IB 6/140, 44801, Bochum, NRW, Germany; E-mail: [email protected]

Polymers are versatile materials. They can be used in var-

ious shapes and colours, and their properties vary in a

broad range. Once polymers are processed into foams, they

show a high stability combined with low weight, due to

the encapsulated gas.

Usually, a foaming procedure consists of several

steps. First, the fluidised polymer is mixed with a blowing

agent. Second, the blowing agent causes the foam struc-

ture via nucleation and growth of gas bubbles into the

polymer matrix. Finally, the foam needs to be stabilised.

The foam morphology is distinguished between open cells

and closed cells, depending on the pore structure. A com-

bination of both types is possible, too, so-called integrat-

ed-foams with dense shells and porous cores. These foams

show a very high rigidity, and the shell prevents water and

dirt penetrating the foam [1].

Several substances have already been investigated

as blowing agents, such as water vapour and low boiling

organic liquids [2]. However, disadvantages like conden-

sation during cooling (vapour) and residues in the foams

(organic liquids) made their industrial application difficult,

especially in the food industry. Therefore, alternative sub-

stances were investigated as blowing agents [3]. Super-

critical fluids like nitrogen or carbon dioxide are promising


substances. They show a high density at elevated tem-

peratures and pressures and dissolve into the polymer.

Hence, residue-free foams with fine pores can be created

by depressurising a polymer-gas-system. Since the solu-

bility of carbon dioxide in polymers is usually higher than

nitrogen, its ability as blowing agent has been investi-

gated.

The application of polymer foams in thermal insu-

lation requires very small pores, a low interconnectivity,

and a robust polymer matrix. Nucleation and growth are

competitive in creating the pore structure, and the final

stabilisation has a great influence on the foam properties.

It is therefore important to investigate the quasi-binary

system polymer-carbon dioxide during the whole proce-

dure and determine its behaviour and properties under

different parameters.

In general, the melt behaviour and rheology of the

polymer-carbon dioxide mixture under high pressure and

temperature influences its handling. Due to the dissolution

of carbon dioxide into the polymer matrix, the melting

temperature of the polymer decreases. This so-called gas

induced melting point reduction enables economisation

by saving heating energy. The gas-enriched polymer melt

usually shows a lower viscosity, too. It is therefore easier

to process the polymer through a plant. However, solubil-

ity and diffusion coefficients have to be determined, since

they are influencing the amount of gas dissolved into the

polymer, and therefore, the quality of porous structures

created. The concentration of carbon dioxide in the poly-

mer phase is crucial in the foaming procedure, as a certain

amount of dissolved gas is needed to expand the polymer

sufficiently. The mixing behaviour of polymers and carbon

dioxide is also important, since a good miscibility enables

foams with a more homogeneous pore size distribution.


Once the polymer-gas-system is depressurised, short

chain length components such as additives or residue mono-

mers might be extracted. Thus, the properties of the remain-

ing porous polymer matrix differ from them of the original

polymer. The separation of the gas phase from the polymer

foam is the most crucial step in processing. For producing

polymer foams in large dimensions and quantities, con-

tinuous processes are preferable to batch-wise procedures.

However, high pressure conditions in continuously oper-

ated procedures are more complicated to achieve, since

their leak tightness has to be ensured. If a porous foam is

created in a mould, the ability to separate between foam

and mould is also of great importance, once the foam needs

to be taken out. If it is generated as a free foaming mech-

anism, the separation rate of gas and foam should be lim-

ited to avoid disrupted structures. The simultaneous and

consecutive appearance of thermodynamic phenomena

during processing defines the properties and applications

of the created foam.

REFERENCES:

[1] A. Kauffmann, H. Schüle, Schäumen, in: Eyerer, P. et al. (Ed.) Polymer

Engineering – Technologien und Praxis; Springer, Berlin (u.a.), 2008,

pp. 286-295.

[2] F. A. Shutov, Blowing Agents for Polymeric Foams, in: D. Klempner, V.

Sendijarevic (Hrsg.) Polymeric Foams and Foam Technology, 2nd edi-

tion; Hanser, Munich, 2004, pp. 505-548.

[3] V. Altstädt, A. Mantey, Thermoplast-Schaumspritzgießen, Hanser,

München (2011).

POSTERS

OBTAINING DEFATTED SEEDS AND OIL RICh IN TOCOTRIENOLS FROM ANNATTO By SUPERCRITICAL ExTRACTION: STUDy OF PROCESS PARAMETERS, SCALE-UP AND ECONOMIC FEASIBILITy

245

OBTAINING DEFATTED SEEDS AND OIL RICh IN TOCOTRIENOLS FROM ANNATTO By SUPERCRITICAL ExTRACTION: STUDy OF PROCESS PARAMETERS, SCALE-UP AND ECONOMIC FEASIBILITy

carolina L. c. Albuquerque, M. Angela A. MeirelesDepartamento de Tecnologia de Alimentos,

Centro de Tecnologia e Desenvolvimento Regional, Universidade Federal da Paraíba – Campus V;

Distrito Industrial de Mangabeira, Via Local, s/n.,Quadra 252, Lote 501, 58.055-000, João Pessoa, PB, Brazil;


This work presents a study of the supercritical fluid ex-

traction (SFE) of annatto oil to obtain defatted seeds and

extract rich in tocotrienols. The work consisted in studying

the process parameters, the scale-up and economic fea-

sibility. A review of the annatto agribusiness showed a

trend of using annatto due to the increasing consumer

demand for natural products because the seeds are rich

in tocotrienols, which are antioxidant and hypocholester-

olemic substances. However, the socioeconomic evalua-

tion of the producers, the recovery of higher quality extract,

and the use of process byproducts were found as the main

points that still needed to be improved. Supercritical Tech-

nology has the advantage of obtaining solvent-free extracts

and residue that add value to the products and byproducts

of the process. Thus, a preliminary study of economic fea-

sibility of the SFE process of annatto oil was carried out

using the available data in literature. The study showed

that the SFE of annatto oil was economically feasible with

no data optimized, since the cost of manufacturing (COM)

of extracts, for various industrial scales, were US$ 382.82/

kg (100 L), US$ 258.54/kg (500 L) and US$ 232.88/kg (1000


L). Therefore, optimized conditions of the process were

determined with the experimental assays at 313 and 333 K

and 20, 31, and 40 MPa. Larger amounts of oil were ob-

tained in 333 K/40 MPa. In these conditions, kinect ex-

periments were carried out and the COM of extracts was

estimated as a function of extraction time. The optimiza-

tion of process time decreased the COM for the capacities

100 and 500 L to US$ 124.58/kg and US$ 109.27/kg respec-

tively. Extract more concentrated in δ-tocotrienol, (14.6 ±

0.4)% was obtained at 313 K/20 MPa. In this condition, the

lowest bixin content was obtained in the extract, (0.9 ±

0.1)%. Therefore, an extract rich in functional substances

and defatted seeds, and rich in bixin for later extraction

were obtained with different feasible COM for industrial

scales. The overall extraction curves (OECs) determined

in a 5 L unit at 313 K/20 MPa showed that the scaling-up

criterion used in the SFE simulation to estimate the COM

was validated. The criterion was to keep constant the mass

of solvent to mass of feed ratio (S/F) and the solvent resi-

dence time obtained in laboratory scale. The OECs in both

scales had similar performance, with similar yield of ex-

tract and tocotrienols. The COM of the extracts was esti-

mated for different scenarios considering three different

stakeholders: investor, producer and colorant industries.

The raw material cost ranged from 0.00 to 2.20 US$/kg. In

the investor’s scenario, the best process time, from the

economic standpoint, was 105 minutes, with COM (115±5)

US$/kg for a 500 L and S/F of 8.7. For producer and indus-

try scenarios, the lowest COMs were (40±6) US$/kg, (15±2)

US$/kg, and (12±1) US$/kg, obtained at 28 minutes and

S/F of 3.1 for capacities of 50, 300 and 500 L, respectively.

The payback period ranged between 1-5 years for the pro-

ducer selling oil, waste, and defatted seed which has high

bixin content. The colorant industry use defatted seeds

POSTERS 247

for colorant production, and sells the oil. This study showed

that the SFE is economically feasible for units of at least

50L. Moreover, the process has the advantage of producing

seed with reduced or controlled oil content, and extract

with different concentrations of δ-tocotrienol, only by ad-

justing the operating conditions of the process.

ThE SUBCRITICAL WATER hyDROLySIS OF ANNATTO (BixA oRELLAnA L.) SEED RESIDUES

249

ThE SUBCRITICAL WATER hyDROLySIS OF ANNATTO (BixA oRELLAnA L.) SEED RESIDUES

sylvia c. Alcázar-Alay, Tania forster-carneiro, M. Angela A. Meireles

LASEFI/DEA/FEA (School of Food Engineering), UNICAMP (University of Campinas);

R. Monteiro Lobato, 80, 13083-862, Campinas, SP, Brazil; E-mail: [email protected]

Lignocellulosic residues are potential sources of bioener-

gy due to their high availability and high renewable po-

tential. Hydrothermal technologies, especially supercritical

and subcritical technologies, have delivered excellent re-

sults in the conversion of biomass by a hydrolysis process

that features the main advantage of using non-toxic sol-

vents and less time for conversion in comparison to other

methods of hydrolysis. Further, selectivity in the degrada-

tion of polysaccharides, proteins and lipids can be achieved

by varying the water properties with temperature and pres-

sure. The final products of hydrolysis are monosaccharides

and oligosaccharides, pentoses, hexoses, organic acids and

amino acids that are of significant commercial interest to

the food, chemical and energy industries. Defatted annat-

to seeds are obtained after the separation processes (the

extraction of active soluble compounds and pigments, ca-

rotenoids) and then are destined as the raw material for

use in the hydrolysis process. The separation of the fat

fraction is conducted using the supercritical fluid extraction

(SFE) method. In a subsequent process, the pigments are

separated from the defatted seed using a low-pressure

solvent extraction (LPSE) method, yielding a solid residue

with a larger fraction of the initial lignocellulosic biomass


that is free of pigments. Finally, the fermentable sugars in

the biomass are obtained after performing the subcritical

water hydrolysis of the defatted annatto. This study aims

to determine the key operating parameters for obtaining

the greatest percentage of fermentable sugars (water-

soluble oligomers, monomers) and amino acids, as well

as reducing the fractions of the degradation products of

hydrolysis and organic acids using subcritical water. The

main variables of the process are the temperature, pres-

sure, solvent mass to mass feed (S/F) ratio and use of CO2.

The hydrolysis products are analyzed for pH, total reduc-

ing sugars, monosaccharides and degradation products.

The S/F is analyzed in the range from 1/5 to 1/15 (the

highest ratios promote the dissolution of polysaccharides,

while lower ratios promote lower water consumption). The

effect of adding CO2 as a catalyst solvent is evaluated in

the proportion CO2/H

2O (v/v) 1/10. The temperature range

is from 420 to 520 K (the subcritical region) and the pres-

sure is between 10 and 20 MPa, which yields a condition

in which the pressure of the medium is higher than the

saturation pressure at all temperature conditions selected

for this study. The results obtained with pure water as

reaction medium are compared with the results obtained

using water + CO2 as the reaction medium.

ACKNOWLEDGEMENTS

The authors acknowledge the financial support from CAPES (DEA/FEA/

PROEX); and partial support from FAPESP (2009/17234-9 and 2012/10685-8)

is also acknowledged. S. C. Alcázar-Alay thanks CAPES for the Ph.D. as-

sistantship. M. A. A. Meireles thanks CNPq for the productivity grant

(302778/2007-1).

251

IDTq — A NEW RESEARCh GROUP LOCATED IN CORDOBA, ARGENTINA: PhASE EqUILIBRIUM, ExTRACTION, PURIFICATION AND MODELLING CAPABILITIES

Alfonsina E. Andreatta*, Juan M. Milanesio, Raquel E. Martini, M. f. Barrera vazquez

IDTQ – Grupo Vinculado PLAPIQUI – CONICET – FCEFyN, Universidad Nacional de Córdoba;

X5016GCA, Av. Vélez Sarsfi eld 1611, Córdoba, Argentina;E-mail: [email protected]

*Universidad Tecnológica Nacional, Facultad Regional San Francisco;

Av. de la Universidad 501, 2400, San Francisco, Córdoba, Argentina

IDTQ is a recently developed research group with a high

potential and mainly focused on supercritical technology

applied to the extraction of natural products and its use on

human health, and also applied to solve energy problems.

Plants with important properties for human health

accompany mankind from its origins. In spite of the great

evolution of health sciences, pathologies still exist without

a definitive cure or with therapies that cause undesirable

effects. Within this frame it is necessary to search new

therapeutic agents.

Traditional processes of extraction and purification

of natural products are: pressing, hydro-distillation, steam

stripping and liquid organic solvent extraction. These tra-

ditional methods require high residence time, big quantities

of solvent and they present low selectivity. New techniques

such as the application of supercritical fluids [1], micro-

wave assisted extraction [2-4], ultrasound [4,5] and pres-

surized water [6,7] are among the new methods used in

the industrial field to recover the bioactive compounds

present in natural products. In this sense, we present dif-


ferent natural products that were used to test these new

extraction methods. The recovery of anthraquinones from

cegadera, tannin from grapeseed, catechins from green

tea and different bioactive compounds were studied in our

lab.

To model the equilibrium of these mixtures the use

of a group contribution approach is a logical choice. In

this way a group-contribution with association equation

of state GCA-EOS [8] was applied to represent phase equi-

librium data on mixtures containing the compounds in

study with different solvents in a high range of condition

including supercritical conditions. The extension of the

GCA-EoS model will allow to represent a large set of nat-

ural products with complex chemical structures, and to

evaluate traditional and supercritical processes using the

equation predictive capability.

REFERENCES

[1] D. J. Miller, S.B. Hawthorne, J. Chemical & Engineering Data, 45 (2000)

315-318.

[2] A. Navarrete Muñoz, Tesis Doctoral. Universidad de Valladolid, 2010.

[3] B. G. Terigar, S. Balasubramanian, C. M. Sabliov, M. Lima, D. Boldor,

J. Food Engineering, 104 (2011) 208-217.

[4] S. Hemwimon, P. Pavasant, A. Shotipruk, Separations and Purification

Technology, 54 (2007) 44-50.

[5] M. Dabiri, S. Salimi, A. Ghassempour, A. Rassouli, M. Talebi, J. Sepa-

ration Science, 28 (2005) 387-396.

[6] M. D. Luque de Castro, M.M. Jiménez-Carmona, V. Fernández-Pérez,

Trends in Analytical Chemistry, 18 (1999) 708-716.

[7] D. J. Miller, S. B. Hawthorne, A. M. Gizir, A. A. Clifford, J. Chemical &

Engineering Data, 43 (1998) 1043-1047.

[8] H. P. Gros, S. Bottini, E. A. Brignole, Fluid Phase Equilibria, 116 (1996)

537-544.

ThE SUPERCRITICAL FLUID ExTRACTION OF ANTIOxIDANT COMPOUNDS FROM ABIU SKIN

253

ThE SUPERCRITICAL FLUID ExTRACTION OF ANTIOxIDANT COMPOUNDS FROM ABIU SKIN

Elena M. Balboa, herminia Domínguez Departamento de Enxeñería Química,

Universidade de Vigo; Campus Ourense, Edifi cio Politécnico, As Lagoas, 32004 Ourense, Spain

CITI-Universidade de Vigo; Parque Tecnolóxico de Galicia, Rúa Galicia 2, 32900 Ourense, Spain

Angela M. farías-campomanes, M. Angela A. MeirelesLASEFI/DEA/FEA (School of Food Engineering),

UNICAMP (University of Campinas);R. Monteiro Lobato, 80, 13083-862 Campinas, São Paulo, Brazil;


carlos v. Lamarão pereira, valdir f. veiga Jr. Departamento de Química, ICE,

Universidade Federal do Amazonas; Av. Gal. Rodrigo Octávio, 3.000, Coroado II, Manaus, Brazil

Abiu (Pouteria caimito) is a tropical fruit that is native to

the Amazonian region of Brazil. Abiu is predominantly

eaten raw or used for the preparation of juice or ice cream.

The skin of abiu is not usable, so it is considered to be a

residue of the peeling process. However, the skin contains

a significant amount of oils and phenolic compounds. The

abiu fruit has traditionally been used to relieve coughs,

bronchitis and other pulmonary afflictions but also as as-

tringent, anti-anemic and anti-inflammatory properties.

Additionally, some studies have shown that abiu has a high

phenolic content [1] and strong α-amylase and α-gluco-

sidase inhibitory activities that reduce postprandial blood

glucose levels [2]; as a result, it is believed that the skin

of abiu also might possess interesting properties. Super-

critical fluid extrac tion (SFE) is a clean process that can

be used to obtain high-quality extracts from plants or


derivatives. Carbon dioxide is the most commonly used

solvent because it is cheap, environmentally friendly and

generally recognized as safe (GRAS). Further, carbon diox-

ide has high diffusivity, allows for the recovery of solvent-

free extracts because of its gaseous form at room temperature,

and allows for the extraction of thermally labile or easily

oxidized compounds because the process is carried out at

low temperatures using a non-oxidizing medium [3]. The

aim of this study is to determine the best conditions of

antioxidant recovery from the skin of abiu by using super-

critical carbon dioxide at varying conditions of pressure

and temperature. Due to the lack of previous literature

results on the SFE extraction of this raw material, a wide

range of pressures (15, 20, 25, 30 and 35 MPa) and tem-

peratures (40, 50 and 60 °C) were studied. The assays were

performed in duplicate. The extracts were evaluated for

global yield and antioxidant activity based on the coupled

reaction of β-carotene and linolenic acid [4]. The abiu fruit

was processed, and the residual skin was collected, dried,

milled and stored at -18 °C in a plastic bag for protection

from light. The extractions were carried out in a commercial

SFE system equipped with an electric oven and a pneu-

matic pump (Spe-ed SFE Laboratory System, 7071, Applied

Separations, Allentown, USA). Because of the antioxidant

capacity and phenolic content of abiu skin, the extracts

are probable candidates for use as active ingredients in

pharmaceutical, functional food and cosmetic industries.

ACKNOWLEDGMENTS

This work is part of the Ph.D. thesis of E. Balboa. E. Balboa thanks the

Spanish Ministry of Education and Science for her FPI grant (BES-2010-

041807). A. M. Campomanes-Farias thanks CAPES/PEC-PG for the Ph.D.

assistantship. The authors are thankful for the financial support from CNPq,

CAPES-PROEX.

POSTERS 255

REFERENCES

[1] S. A. Assis, J. C. R. Vellosa, I. L. Brunetti, N. M. Khalil, K. M. D. S. C.

Leite, A. B. G. Martins, O. M. M. D. F. Oliveira, Antioxidant activity,

ascorbic acid and total phenol of exotic fruits occurring in Brazil, Inter-

national J. Food Sciences and Nutrition, 60, 5 (2009) 439-448.

[2] P. M. De Souza, P. M. De Sales, L. A. Simeoni, E. C. Silva, D. Silveira, P.

De Oliveira Magalhães, Inhibitory activity of α-amylase and α-glucosidase

by plant extracts from the Brazilian cerrado, Planta Medica, 78, 4 (2012)

393-399.

[3] M. Herrero, J. A. Mendiola, A. Cifuentes, E. Ibáñez, Supercritical fluid

extraction: Recent advances and applications, J. Chromatography A,

1217, 16 (2010) 2495–2511.

[4] P. F. Leal, N. B. Maia, Q. A. C. Carmello, R. R. Catharino, M. N. Eberlin,

M. A. A. Meireles, Sweet basil (Ocimum basilicum) extracts obtained

by supercritical fluid extraction (SFE): global yields, chemical compo-

sition, antioxidant activity, and estimation of the cost of manufacturing,

Food Bioprocess Technology 1, 4 (2008) 326-338.

ANTIOxIDANT, hyPOLIPEMIANT AND ANTI-OBESITy ACTIVITIES OF cAsEARiA syLvEsTRis ExTRACTS OBTAINED FROM SFE AND LPE, AND ExPERIMENTAL PhASE EqUILIBRIUM BEhAVIOR DETERMINATION

257

ANTIOxIDANT, hyPOLIPEMIANT AND ANTI-OBESITy ACTIVITIES OF cAsEARiA syLvEsTRis ExTRACTS OBTAINED FROM SFE AND LPE, AND ExPERIMENTAL PhASE EqUILIBRIUM BEhAVIOR DETERMINATION

patícia Benelli, sibele R. Rosso comim, Evelin c. Azevedo, Rozangela c. pedrosa,

sandra R. s. ferreiraFederal University of Santa Catarina (UFSC), EQA/CTC; CP 476 – Trindade, 88040-900, Florianópolis, SC, Brazil;


Antioxidants, either as additives or as pharmaceutical sup-

plements, can end radical reactions in vivo which can dam-

age essential molecules such as nucleic acids and proteins.

The natural antioxidant compounds have been isolated

from different kind of natural products, including flavonoids,

phenolic acids, terpenes, tocopherols and phospholipids.

These compounds can also be responsible for hypolipemi-

ant and anti-obesity activities, which mean compounds

used for hyperlipidemia treatments (excess of cholesterol,

triglycerides and glucose levels) and excess of weight gain.

Casearia sylvestris is a native medicinal plant in Brazil,

Peru, Argentina, Uruguay and Bolivia. The leaves of the

plant are popularly used in folk medicine as antiseptic,

topical anaesthetic, antitumor and antiulcer agents, and

to heal skin wound diseases. In the Casearia extracts there

are substances of great interest, such as coumarins, fla-

vonoids and diterpenes, especially clerodane diterpenes

as casearins and casearvestrins, which are bioactive with

excellent cytotoxic and antitumor potential. Supercritical

fluid extraction (SFE) is an alternative process to conven-

tional extractions in various applications due to the pos-


sibility to obtain solvent-free extracts and the use of low

extraction temperatures, warranting the process selectivi-

ty towards the bioactive compounds. Considering the im-

portance of these compounds the knowledge of the phase

equilibrium of natural extracts in supercritical fluids, ob-

tained by experimental measurements, is fundamental for

determination of optimal conditions for separation and

precipitation processes conducted at higher pressures,

especially for food and pharmaceutical industries. The aim

of the present project is to obtain and compare the extract

attainment from C. sylvestris by SFE with CO2 and CO

2

with co-solvent and low pressure extractions as Soxhlet

(SOX) and maceration (MAC) with different solvents. The

techniques efficiency was compared in terms of process

yield and antioxidant capacity, evaluated by DPPH assay,

β-carotene bleaching method and total phenolic content

(TPC). The anti-obesity and hypolipidemic effects were

also evaluated in vivo submitting Mus musculus Balb/c

mice to a high-fat diet combined with C. sylvestris extracts

during 30 days, monitoring the animals’ weight during the

treatment and the final total serum cholesterol, triglycerides

and glucose levels. The TPC presented maximum values

of 169.4±0.6 mgGAE/g (SOX-ETOH) and 135±4 mgGAE/g

(MAC-ETOH). The antioxidant potential by DDPH meth-

od resulted in effective concentration at 50% (EC50) val-

ues of 254±3 µg/mL (SFE 50 ºC/200 bar+11% ETOH) and

245±4 µg/mL (SFE 300 bar/50 °C+8% ETOH) and the

β-carotene method presented values of 108±3% for SFE

sample obtained at 50 ºC/300 bar+5% ETOAC and 110±1%

obtained at 50 ºC/200 bar+2% ETOAC extract, after 120

minutes-reaction. The best anti-obesity results were ob-

tained for the diet using SFE extracts 300 bar/50 ºC+5%

ETOH and 300 bar/50 ºC+5% ETOAC among the extracts

tested. The lowest cholesterol levels were provided by

POSTERS 259

SOX-ETOH and SOX-ETOAC extracts and the highest

glucose reduction were observed by treating the animals

with SFE 300 bar/50 ºC and SFE 300 bar/50 ºC+5% ETOH

extracts. The groups treated with extracts obtained at SFE

300 bar/50 ºC+5% ETOH and SOX-ETOAC presented low-

er triglycerides levels. The continuation of this work will

perform the antioxidant evaluation by ABTS radical and

lipid peroxidation in vitro (TBARS) methods and by the

achievement of the extracts chemical profile by gas chro-

matography coupled to mass spectrometry analysis (GC-

MS), in order to prove the presence of important compounds

with biological activity. Also, the investigation of the phase

equilibrium behavior of systems composed by C. sylvestris

extract, organic solvent and supercritical CO2 will be held

by means of the static synthetic method to afford infor-

mation for the separation and precipitation/encapsulation

processes.

ThE USE OF SUPERCRITICAL FLUID ChROMATOGRAPhy (SFC) IN ThE ANALySIS OF PETROLEUM, GASOLINE AND KEROSENE

261

ThE USE OF SUPERCRITICAL FLUID ChROMATOGRAPhy (SFC) IN ThE ANALySIS OF PETROLEUM, GASOLINE AND KEROSENE

Endler Marcel Borges, Mauricio A. Rostagno, Rodrigo Bisaia, guilherme Romão,




flávio c. Albuquerque CENPES – PETROBRAS R&D Center;

Av. Horácio de Macedo, 950, Cidade Universitária, 21941-915, Rio de Janeiro, RJ, Brazil

As an analytical technique, supercritical fluid chromatog-

raphy (SFC) is complementary to both gas chromatography

(GC) and liquid chromatography (LC). SFC can be applied

to materials that are too heavy to meet the volatility and

thermal stability requirements for GC. Supercritical fluids

possess a combination of gas-like and liquid-like proper-

ties, which enables the elution of high-molecular-weight

materials and faster solute transport within the column.

This property also results in shorter analysis time for SFC

relative to HPLC [1,2].

Hydrocarbon group separation is a very difficult task

because high selectivity toward very similar molecules is

required [3]. SFC with flame ionization detection (FID) has

been shown to work well for hydrocarbon group analysis

[4]. The American Society of Testing and Materials (ASTM)

has accepted the use of SFC for the determination of aro-

matic contents of jet and diesel fuels [2,4] (ASTM D 5186-

96). However, this method is not applicable to crude oil

because crude oil is significantly more complex in com-


position than either jet or diesel fuel. For example, crude

oil contains heavy compounds, such as asphaltenes, res-

ins and several polar compounds.

Evaporative light scattering detection (ELSD) was

originally designed for LC for the detection of non-volatile

compounds by mass [1]. In ELSD, the eluent is nebulized

by a gas stream followed by solvent evaporation, typical-

ly in a heated drift tube. The remaining micro particles of

the non-volatile solid or liquid analyte are then passed

through a beam of light. The incident light is scattered by

the particles and then collected by a photomultiplier ap-

paratus, which generates the signal. Because the detec-

tion mechanism does not rely on the optical properties of

the compound, ELSD is considered a universal detector

and is ideal for detecting analytes without UV chromo-

phores [5].

SFC-FID has been extensively used in the analysis

of petrol and petrol derivatives due to the lack of a sensi-

tive and universal detector that can be used for this pur-

pose. However, the development of the ELSD detector has

changed this situation; in this project, we present a SFC-

ELDS method for the analysis of crude oil and oil derived

products. Our main goal is develop a system and the nec-

essary methodology for the separation of the different com-

pound classes present in crude oil and oil products.

The experimental conditions were optimized using

a test mixture containing hexadecane, toluene, tetralin

(1,2,3,4-tetrahydronaphthalene), naphthalene, pyrene, ben-

zo(a)pyrene and anthracene [6] (test mixture 1). After meth-

od optimization, real samples of kerosene, diesel and petrol

were analyzed.

The separation of the constituents in petrol and pet-

rol derivatives was optimized by varying several experi-

mental conditions, such as the column [Spherisorb S5W

POSTERS 263

(10 x 250 mm, 5 µm), Spherisorb CN (10 x 250 mm, 5 µm),

Spherisorb SCX (10 x 250 mm, 5 µm), Viridis SFC 2-Eth-

ylpyridine (10 x 150 mm, 5 µm)], the temperature (20-60 ºC),

the back pressure (100-300 MPa) and the flow rate (2-12

mL min-1).

The response dependence of ELSD on several com-

mon experimental parameters, including gas flow, co-sol-

vent percentage, evaporation and nebulization temperatures,

was tested with and without a column for each compound

in test mixture.

This work was carried out using modular equip-

ment. The unique configuration of this equipment makes

possible the elution (flush) of three consecutive connected

columns; additionally, by changing the configuration it is

possible to individually backflush each column to collect

selectively each fraction that is separated. The first stage

of method development was initially carried out using one

column without back-flush. The next stage included the

evaluation of two columns with individual back-flush ca-

pabilities. Finally, the last stage included the use of all

three columns connected in series, followed by the se-

quential backflush of each column.

The efficacy of our SFC-ELSD method was demon-

strated for the analysis of several petrol, gasoline and ker-

osene samples, which were provided by the CENPES/

PETROBRAS.

ACKNOWLEDGEMENTS

This work was carried out through cooperation between LASEFI/DEA/FEA/UNICAMP and CENPES/PETROBRAS. The authors acknowledge the finan-cial support from the Brazilian National Agency of Petrol [Agencia Nacion-al do Petróleo (ANP)].

REFERENCES

[1] B. N. Barman, V. L. Cebolla and L. Membrado, Critical reviews in ana-lytical chemistry, 30 (2000) 75-120.


[2] L. T. Taylor, Analytical chemistry, 82 (2010) 4925-4935.

[3] R. M’Hamdi, D. Thiéabaut and M. Caude, J. High Resolution Chroma-

tography, 20 (1997) 545-554.

[4] B. E. Richter, B. A. Jones and N. L. Porter, J. chromatographic science,

36 (1998) 444-448.

[5] E. Lesellier, A. Valarché, C. West and M. Dreux, J. Chromatography A,

1250 (2012) 220-226.

[6] T. Dutriez, D. Thiébaut, M. Courtiade, H. Dulot, F. Bertoncini and M. C.

Hennion, Fuel, 104 (2013) 583-592.

scCO2 POST-PROCESSING OF MATERIALS FOR BIOMEDICAL APPLICATIONS

265

scCO2 POST-PROCESSING OF MATERIALS FOR BIOMEDICAL APPLICATIONS

Mara E. M. Braga, Ana M. A. Dias, hermínio c. de sousa

CIEPQPF – Chemical Engineering Departament, FCTUC, University of Coimbra;

Rua Silvio Lima, s/nº, Pólo II, Pinhal de Marrocos, 3030-790, Coimbra, Portugal;

E-mails: [email protected], [email protected], [email protected]

Post-processing of finished commercially available poly-

mer-based devices is a recent and attractive approach for

the development of multifunctional biomedical devices

and implants, drug release systems and tissue scaffolds.

Materials that are intended to be used for biomedical ap-

plications should satisfy a wide range of requirements in

terms of their biocompatibility/toxicity, surface chemistry/

morphology, porosity and pore morphology/interconnec-

tivity, mechanical properties, degradation and bio-absorp-

tion rates and replacement rate by neo-tissues. The use

of scCO2 for post-processing purposes is a particular ad-

vantageous example which has been widely employed as

a morphological, porogenic, foaming, viscosity reducer

or a plasticizer agent for a wide range of applications that

include polymer/composite processing, micronization of

biocompatible polymers, encapsulation, impregnation or

deposition of bioactive substances into solid matrices

(polymeric/ceramic/composite), and extraction of unde-

sired compounds from the synthesized materials. Some of

these processes such as scCO2-assisted impregnation/

deposition method have an advantage for precise incorpo-

ration of bioactive substances into polymeric, inorganic


and composite materials in a short time and without the

presence of harmful solvent residues. This process permits

to load previously prepared biomaterials or even biomed-

ical articles/devices without interfering with their intrinsic

material properties during the manufacture and/or process-

ing. The ability of polymeric devices to carry and release

specific biological and/or synthetic bioactive substances,

in a temporal- and in a 3D-controlled way, benefits the

involved biological processes when they are used specif-

ically to repair, to regenerate or even to replace a lost func-

tion of a tissue and/or organ involving the use of cells is

studied in the tissue engineering field. Over the last years

our research group has been studying the impregnation/

deposition method on finished devices. Examples of scCO2

processed biomaterials include contact and intraocular

lenses, wound dressings, bioactive glasses, composites,

scaffolds, etc. The impregnation/deposition of acetazol-

amide and timolol maleate into commercial soft contact

lenses to produce anti-glaucoma drug-loaded contact lens-

es was easily obtained by changing the operational pres-

sure, temperature, processing time and depressurization

rate conditions, to control the lenses drug loading capac-

ities. This feature permits to adjust the final drugs release

levels into specific and desired therapeutic limits without

affecting the main properties of ophthalmic devices such

as oxygen permeability, glass transition, contact angle and

optical properties. Another example include the development

of bioactive glasses (that will be used as bone substitute)

loaded with dexamethasone, for which post- processing

became an important step since the synterization process

(required to produce glasses) restrains drug inclusion during

the synthesis to avoid the thermo- degradation of the drug.

This drug deposition method improved the biological ac-

tivities of the prepared bioglasses, increased cell viability

POSTERS 267

and presented osteogenic and anti-inflammatory prop-

erties, as confirmed by in vitro cell assays. These works

dem onstrate that the above referred scCO2-based post-

processing methods can be very useful for the preparation

of polymeric based materials with tunable physicochem-

ical, thermomechanical, morphological and drug release

properties, suitable for biomedical applications.

MEASUREMENT OF LIqUID-VAPOR AND LIqUID-LIqUID-VAPOR EqUILIBRIUM IN CO2 + ORGANIC + IONIC LIqUID TERNARy SySTEMS

269

MEASUREMENT OF LIqUID-VAPOR AND LIqUID-LIqUID-VAPOR EqUILIBRIUM IN CO2 + ORGANIC + IONIC LIqUID TERNARy SySTEMS

Roberto canales, Joan f. BrenneckeUniversity of Notre Dame;

182 Fitzpatrick Hall, 46556, Notre Dame, IN, USA; E-mail: [email protected]

Ionic liquids (ILs) are among the options for replacing con-

ventional volatile organic solvents in industry, due to their

interesting characteristics, such as low volatility, high

thermal stability and the possibility of tuning their phys-

ical and chemical properties (high number of cation-anion

combinations). However, separation of components from

ILs is a challenge since distillation, heating and liquid-liq-

uid extraction are not the best options if we need to pro-

cess thermolabile compounds and to avoid using volatile

organic solvents in the processes. Here we explore the idea

we first suggested in 2002 [1] of using CO2 to induce liq-

uid-liquid phase splits in IL + organic systems.

Originally we showed that polar organics and wa-

ter can be separated from ILs using CO2 [2-4]. For instance,

when methanol is added to [bmim][PF6] it forms a single

phase liquid mixture. Then, CO2 is added to the liquid

phase at constant temperature and the increasing pres-

sure results in a high solubility of the CO2 in the organic

+ IL liquid mixture. This also increases the volume of the

liquid phase and eventually induces a phase split to obtain

liquid-liquid-vapor equilibrium (LLV). The pressure at which

this occurs is called the “cloud point”. If more CO2 is add-

ed to the system forming a LLV equilibrium, there is a

pressure where the organic-rich phase disappears, dis-


solving the organic compound into the supercritical CO2

phase. This is called the “merging point”.

This work is focused on measuring the separation

of toluene from four different ILs based on the bis(trifluoro-

methylsulfonyl)imide ([Tf2N]-) anion. Cations are 1-hexyl- 3-

methylimidazolium ([hmim]+), 1-hexyl-3-methylpyridinium

([hmpy]+), triethyloctyl phosphonium ([P2228]+) and tri-

hexyltetradecyl phosphonium ([P66614]+). Two different

apparatuses, a modification of those shown in another work

from our group [4] are presented for measuring the com-

position in the different phases: a stoichiometric appara-

tus for solubility of CO2 in the single liquid phase mixture

until the cloud point appears and an analytical apparatus

for sampling the phases in LLV equilibrium, which ends

in the merging point of the mixture as the pressure is in-

creased. Solubility of CO2 in the toluene + IL mixture is

measured at 298 K and 313 K (also 333 K for [hmim][Tf2N])

and pressures up to 8 MPa, with initial IL mole fraction of

0.30, 0.50 and 0.70. Results are compared with binary sol-

ubilities of CO2 in the different ILs and toluene.

The solubility of CO2 in the liquid mixture increas-

es with increasing pressure and decreases at higher tem-

peratures. The same trend is observed for binary systems

of CO2 in ILs. The solubility of CO

2 in toluene is lower than

in the pure IL but a crossover is reached at an intermedi-

ate pressure. The solubility of CO2 in liquids mixtures of

toluene + IL increases as the initial concentration of IL is

increased. The cloud point pressure is higher at higher

temperatures and lower initial IL composition. The merg-

ing points increase at higher temperatures and we find

that the values are not dependent on the initial IL concen-

tration. Lower cloud point pressures are observed when

using [hmim][Tf2N] and [hmpy][Tf2N], while slightly high-

er pressures are required for [P2228][Tf2N]. [P66614][Tf2N]

POSTERS 271

shows the largest CO2 solubility in the binary and ternary

systems, but this IL exhibits a very high cloud point pres-

sure.

REFERENCES

[1] A. M. Scurto, S. N. V. K. Aki, J. F. Brennecke, J. American Chemical

Society, 124 (2002) 10276-10277.

[2] A. M. Scurto, S. N. V. K. Aki, J. F. Brennecke, Chemical Communica-

tions, (2003) 572-573.

[3] B. R. Mellein, J. F. Brennecke, J. Physical Chemistry B, 111 (2007)

4837-4843.

[4] S. N. V. K. Aki, A. M. Scurto, J. F. Brennecke, Industrial & Engineering

Chemistry Research, 45 (2006) 5574-5585.

ThE RECOVERy OF hIGh-VALUE-ADDED PRODUCTS FROM PRESSED PALM FIBER USING INTEGRATED SUPERCRITICAL TEChNOLOGy: ExTRACTION AND hyDROLySIS

273

ThE RECOVERy OF hIGh-VALUE-ADDED PRODUCTS FROM PRESSED PALM FIBER USING INTEGRATED SUPERCRITICAL TEChNOLOGy: ExTRACTION AND hyDROLySIS

fiorela p. cardenas-Toro, Tania forster-carneiro, M. Angela A. Meireles



The use of agroindustrial residues has received significant

attention in recent years because such residues can be

used as a source of value-added products, such as bioac-

tives for the food industry and fermentable sugars for sec-

ond-generation ethanol. Supercritical technology provides

an interesting option for the sustainable utilization of bio-

mass as an alternative to conventional solvents. Supercrit-

ical fluid extraction (SFE) and pressurized liquid extraction

(PLE) techniques use solvents, such as CO2 and ethanol,

at elevated pressure and temperature to enhance extrac-

tion performance in comparison with soxhlet extraction

in terms of selectivity. Subcritical water hydrolysis (Sub-

WH) possesses the advantages of short conversion times

and low residue generation; however, a deep understand-

ing of the behavior of this technique is needed for sugar

production optimization. Pressed palm fiber is a residue

obtained from the oil palm industry and contains bioactive

compounds, such as carotenoids (α- and β- carotene), which

are important additives for antioxidant properties. Addi-

tionally, this residue contains cellulose and hemicellulose,

which are sources of fermentable sugars. The objective of

this work was to study integrated SFE or PLE for the re-


covery of extracts rich in carotenoids and, subsequently,

SubWH for the recovery of hydrolysates that are rich in

fermentable sugars. First, the integrated process of SFE

and SubWH was studied. The effect of the operational pa-

rameters (pressure and temperature) on the SFE of carot-

enoids was investigated. The highest SFE extract yield

was observed at 328 K and 20 MPa (2.6% d.b.), while the

highest yield for carotenoid content was obtained at 318 K

and 15 MPa (800 ppm in the extract). The defatted, pressed

palm fiber was used as a raw material for the SubWH ex-

periments. The optimal condition for a product possessing

high sugar formation and low sugar degradation was found

at 523 K, 15 MPa, a solvent/feed of 120 and a space-time

of 2.5 min (yield of 23%, conversion of 84.9%). Second, an

integrated process of PLE and SubWH was investigated

based on the use of a new lot of pressed palm fiber. A

central composite rotational design was carried out to eval-

uate the effects of pressure and temperature on carotenoid

recovery. The continuous increment of global yield was

observed with the increment of temperature and pressure,

and the highest carotenoid recovery was found at 328 K and

4 MPa (4,000 ppm in the extract). Subsequent SubWH ex-

periments for kinetic studies at 523 K and 15 MPa are un-

der evaluation. Additionally, an economic analysis of the

proposed integrated processes will be evaluated. The in-

tegration of extraction and hydrolysis provides a promising

method for the recovery of carotenoids and fermentable

sugars from pressed palm fiber.

ACKNOWLEDGEMENTS

The authors thank the Agropalma S.A. Company for supplying the pressed palm fiber residues and acknowledge the financial support from (DEA/FEA/PROEX), CNPq (560914/2010-5) and FAPESP (2011/19817-1 and 2012/10685-8). F. P. Cardena-Toro thanks CAPES/PEC-PG (5945100) for the Ph.D. as-sistantship, and M. A. A. Meireles thanks CNPq for the productivity grant (302778/2007-1).

SUPERCRITICAL FLUID TEChNOLOGIES, INC.

275

SUPERCRITICAL FLUID TEChNOLOGIES, INC.

Thayane carpanedo LabSolutions;

R. Marquês de Olinda, 680, 04277-000 São Paulo – Ipiranga, SP, Brazil; E-mail: [email protected]

Rudy Baskette, Kenneth J. JamesSupercritical Fluid Technologies, Inc.;

19711 Newark, DE, USA;E-mail: ken.james@supercriticalfl uids.com

Supercritical fluid extraction (SFE) is an excellent method

to concentrate flavors, fragrances, essential oils, biologi-

cally active compounds and materials of interest from

flowers, leaves, fruits, bark, roots, buds, seeds, etc. SFE

produces oils with standardized concentration of active

ingredients and products with much higher yield and pu-

rity concentration of active ingredients and products. SFE

also produces oils of higher quality than traditional meth-

ods and with less creation of artifacts. Hops can add re-

markable depth to the flavor profile of a beer by amplifying

fruity, spicy, woodsy, or citric flavors. This experiment will

demonstrate that the SFT-110 SFE Unit can use supercrit-

ical carbon dioxide to separate aromatic and bitter hop

components.

277

VOLATILE OIL ExTRACTION FROM TURMERIC (cuRcuMA LongA L.) By SUPERCRITICAL CARBON DIOxIDE: STUDy OF ThE ExTRACTION IN BEDS OF DIFFERENT GEOMETRIES AND OPERATIONAL CONFIGURATIONS

pedro ivo n. de carvalho, Mauricio A. Rostagno, M. Angela A. Meireles



Production of extracts from vegetal matrices with biolog-

ical properties has attracted great interest of food, cos-

metic, and pharmaceutical industries. Within this demand,

the extraction process using supercritical carbon dioxide

(SFE-CO2) has been shown being a technically and eco-

nomically feasible technology for the extraction of several

substances. It has some advantages over conventional

extraction techniques, both in terms of yield and quality

of the extract. Thus, the first objective of this work is the

application of SFE-CO2 in the optimization of volatile oil

extraction from turmeric in laboratorial scale. This oil is

rich in ar-turmerone, compound that has been reported in

the literature by presenting some bioactive properties, such

as, anti-inflammatory, antimicrobial, antioxidant and an-

ticarcinogenic activity [1].

Currently, in the SFE-CO2 context it becomes im-

portant the generation of knowledge and methodologies

of scale-up towards the industrial application of the SFE-CO2

process. However, some situations that may take place in

extractors of industrial scale, and even, pilot scale, such

as bed porosity, temperature gradient and inefficient sol-


vent dispersion [2] have not been taken into account by

the most simple criteria of scale-up. For instance, in tall

extraction columns axial dispersion can occur and in ex-

tractors of larger diameters can result in heterogenic extrac-

tion due to radial effects inside of extractor [3]. In this work

is proposed the study of bed geometry influence (height

and diameter of the extractor), as well as of variations

associated with this factor (as temperature gradient and

solvent distribution), in the extraction kinetic of the tur-

meric volatile oil.

The installation of a continuous SFE process is oth-

er important point in industrial scale. Continuous process

of extraction is possible and avoids “dead” times in the

process due to the steps of de-pressurization, unloading

of exhausted substrate, loading of fresh substrate, and

re-pressurization [4]. In a extraction plant equipped with

two or more extractors, while one extractor is being reload

with fresh raw material, the other one (or the others) is

working [5]. With the extractors positioned in parallel the

solvent stream is alternating between the columns in each

period wherein the yield intended is reached. In this con-

figuration mode, just one extractor is in operation. With

two or more extractors positioned in series, the process is

called counter-current. The supercritical carbon dioxide

stream is put on in contact with the substrate more ex-

hausted and then successively with the substrate more

rich in solute. This work aims to define which the best

configuration to the extraction columns (extractors in se-

ries or in parallel) taking into account technical and eco-

nomical parameters using turmeric as raw material.

The compounds present in the extract of the volatile

oil will be identified by gas chromatography-mass spec-

trometry (GC-MS) and will be quantified by gas chroma-

tography with flame ionization detection (GC-FID). Finally,

POSTERS 279

the cost of manufacturing of extracts will be estimated

using the simulator SuperPro Designer® 8.5.

ACKNOWLEDGEMENTS

Authors are grateful to CNPq (470916/2012-5) for the financial support;

partial support from FAPESP (2012/10685-8) is also acknowledged. Pedro Ivo

N. de Carvalho thanks CNPq for the MSc. assistantship. M. A. A. Meireles

thanks CNPq for the productivity grant (302778/2007-1).

REFERENCES

[1] B. Chempakam, V. A. Parthasarathy, Turmeric, in: V. A. Parthasarathy, B.

Chempakam, T. J. Zachariah (Ed.) Chemistry of Spices; CAB Interna-

tional, 2008.

[2] J. M. del Valle et al., Supercritical CO2 processing of pretreated rose-

hip seeds: effect of process scale on oil extraction kinetics, J. Super-

critical Fluids, 31(2) (2004) 159-174.

[3] G. Brunner, Gas extraction. An introduction to fundamentals of super-

critical fluids and the application to separation processes; Springer,

New York, 1994.

[4] R. Eggers, P. T. Jaeger, Extraction Systems, in: G. Liadakis, C. Tzia (Ed.)

Extraction Optimization in Food Engineering; CRC Press, 2003.

[5] G. A. Núñez, C. A. Gelmi, J. M. del Valle, Simulation of a supercritical

carbon dioxide extraction plant with three extraction vessels, Com-

puters and Chemical Engineering, 35(12) (2011) 2687-2695.

PRE-SALT RESERVOIR FLUID BEhAVIOR

281

PRE-SALT RESERVOIR FLUID BEhAVIOR

osvaldo chiavone-filho Department of Chemical Engineering,

NT/PPGEQ/NUPEG, Federal University of Rio Grande do Norte (UFRN); Campus Universitário, Lagoa Nova,

59066800, Natal, Rio Grande do Norte, Brazil; E-mail: [email protected]

Eduardo Mach Queiroz, fernando Luiz pellegrini pessoaFederal University of Rio de Janeiro;

CT, BL E, SL 209, Ilha do Fundão, 21949900, Rio de Janeiro, RJ, Brazil; E-mails: [email protected], [email protected]

The reserves of oil and gas in the pre-salt region are esti-

mated in Brazil to be huge and the best are the expectations.

This research work may initially be called “thermodynam-

ic and transport fluid behavior of reservoir mixtures in the

pre-salt conditions of temperature, pressure and compo-

sition”. The presence of species in supercritical conditions

and in significant amounts should be taken into account,

that is the case of carbon dioxide and methane. This fact

plays certainly influence in reservoir behavior and this

research work aims to describe this effect through two

lines, i.e., phase equilibrium thermodynamics and flow

process simulation. The methodology was basically direct-

ed to experimental data collection, study and definition

of the mathematical models, and simulators, or computa-

tional tools, to describe the thermodynamic and transport

fluid behavior of reservoir mixtures in the pre-salt condi-

tions of temperature, pressure and composition. The char-

acterization of the fluid was initially restricted to ten species:

methane, ethane, propane, carbon dioxide, water, sodium

chloride, calcium carbonate, cyclohexane, n-decane and


hexacosane. The conditions of temperature and pressure

of interest are initially 60 to 120 ºC and 120 to 700 bar,

respectively. Therefore, species like methane, ethane, pro-

pane and carbon dioxide are in supercritical (SC) condi-

tions. Another relevant information is that there exists

wells of the pre-salt in operation that present outstanding

production of 20 mil barrels per day, but at the same time

many other wells show production much lower than ex-

pected. Thus a better understanding of the system in con-

ditions of the pre-salt may explain these results of low

production that are contradicting the expectations of the

pre-salt. Preliminary simulations using a cubic equation

of state are presenting and demonstrate that an adequate

approach is able to give a panoramic view of the thermo-

dynamic and transport properties. Results of phase en-

velope, multiphase flash with stability test, density and

viscosity are presented. It may be pointed out that the

presence of carbon dioxide with concentration in the order

of 15% plays influence in the studied properties of the mix-

ture. Commercial simulators usually applied in the de-

scription of reservoirs do not consider the presence of

supercritical species in the evaluation of the thermody-

namic and transport properties and this phase concept is

fundamental in the pre-salt mixtures of severe conditions

of pressure and temperature. Beyond the preliminary re-

sults of simulation, a brief revision of the adequate ther-

modynamic models to describe the pre-salt fluid behavior

is presented. The experimental information selected, main-

ly volumetric measurements, for the systems of interest

are collected in a form of a data bank collection. The pres-

ences of water and salts are also considered and salt sol-

ubility measurements of carbonates under carbon dioxide

atmosphere and in the presence of an organic solvent is

presented and discussed. Furthermore, this experimental

POSTERS 283

procedure is also described. Another observation for elec-

trolyte systems is the evidence of high temperature and

pressure vapor-liquid equilibrium data where the presence

of dissolved salts is found in the fluid phase similarly as

in the aqueous liquid phase. These evidences found in the

literature reinforce the complexity of the mixtures formed

in the pre-salt reservoir and demand of systematic research

and also in cooperation between several laboratories. This

cooperation is being feasible with the aid of the Human

Resources Programs sponsored by the National Agency

of Petroleum, Natural Gas and Biofuels and also by the

Petrobras University. In this research a work group has

been installed and has joined academic institutions cov-

ering the whole Brazil. These programs are forming stu-

dents in the undergraduate and graduate levels and they

are also critical mass to determine and calculate thermo-

dynamic and transport properties in study.

GREEN BIOREFINERy BASED ON SUPERCRITICAL CARBON DIOxIDE TEChNOLOGy FOR ThE PROCESSING OF DISTILLERS GRAINS

285

GREEN BIOREFINERy BASED ON SUPERCRITICAL CARBON DIOxIDE TEChNOLOGy FOR ThE PROCESSING OF DISTILLERS GRAINS

ozan nazim ciftci, feral TemelliUniversity of Alberta;

6020-118 Street South Campus AFDP, T6H2V8, Edmonton, Alberta, Canada;


Even though supercritical carbon dioxide (scCO2) extrac-

tion has been accepted as a superior extraction method,

the general interest is still towards the extraction of low-

volume, high-value products. One way to widen the ap-

plication of scCO2 extraction is by taking full advantage of

the benefits of scCO2 processing, and this can be achieved

by scCO2 processing as part of a biorefinery. Development

of integrated supercritical processes for the green process-

ing of dried distillers grains with solubles (DDGS) using

the biorefinery concept to produce biodiesel, nutraceuti-

cals, and high-value food ingredients such as encapsulates

and delivery systems for bioactives as natural food ingre-

dients is the main focus of this research. DDGS is an in-

expensive byproduct of the ethanol industry. Currently,

DDGS is used as a livestock feed. However, its real value

is underestimated when its high lipid content and high

value minor lipid compounds such as phytosterols, tocols

and carotenoids are considered. Therefore, the objective

of this project is to add value to DDGS by the extraction of

lipids from DDGS with scCO2, fractionation of high-value

components such as tocols, phytosterols and carotenoids

from lipids of DDGS by scCO2, enzymatic conversion of

extracted DDGS lipids to fatty acid methyl esters (FAME,


biodiesel) in a novel continuous scCO2 bioreactor, and pro-

duction of micro- and nanoparticles using the minor lipid

and the protein fractions of the DDGS. DDGS was demon-

strated to be a good source of lipids and valuable minor

lipid components, which can be extracted using scCO2.

Developed biodiesel process based on lipase catalyzed

transesterification of triglycerides yielded FAME contents

of up to 95%, and has many advantages over convention-

al biodiesel process. It is simple, efficient and green. This

process can use a variety of feedstocks, low quality oils,

does not need catalyst removal, has fewer processing steps,

no wastewater is produced and immobilized enzyme can

be reused. No glycerol separation may be needed due to

the very low glycerol content of the product. Ongoing par-

ticle formation studies using the supercritical antisolvent

(SAS) process resulted in successful encapsulation of the

high value minor lipids with the zein fraction of the corn

DDGS residue obtained after lipid extraction. Encapsu-

lates as small as 100 nm were achieved using the SAS

process. scCO2-based biorefining of DDGS may be a prom-

ising way to add value to this byproduct; it may contribute

to the sustainability of the ethanol plants and may poten-

tially open a door for the scCO2 extraction of commodity

oils.

287

PhASE EqUILIBRIUM DATA OF MULTICOMPONENT SySTEMS FOR NANOENCAPSULATION PURPOSES

sibele R. Rosso comim, Thaís A. proença, natália Mezzomo, José vladimir de oliveira,

sandra R. s. ferreiraFederal University of Santa Catarina (UFSC), EQA/CTC; CP 476 – Trindade, 88040-900, Florianópolis, SC, Brazil;


Carotenoids and ω-3 fatty acids are substances present

in the Pink shrimp (P. brasiliensis and P. paulensis) residue

with potential application as additives in the food indus-

try due to their nutritional importance, colorant potential,

antioxidant and hypolipidemic activities. On the other hand,

anthocyanis present in the grape pomace from Merlot

(Vitis vinifera) besides being antioxidants may offer anti-

inflammatory, anti-viral and anti-cancer benefits. However,

these substances are highly unstable. In order to preserve

the cited important biological activities, these extracts can

be encapsulated by high pressure techniques, such as SAS

(Supercritical Anti-Solvent process). The size control of

particles formed in the SAS process depends on the knowl-

edge of the equilibrium data of the involved compounds.

Best conditions for SAS experiments, where smaller par-

ticles are formed, are defined in the P-x phase equilibrium

diagrams as the single phase areas near the critical mix-

ture point (with high anti-solvent content). Therefore, this

work aimed to investigate the phase equilibrium behavior

of the multicomponent systems: shrimp residue extract +

acetone + carbon dioxide (CO2), pluronic + acetone + CO

2

and shrimp residue extract + pluronic + acetone + CO2 in

order to understand the changes in the acetone + CO2


phase equilibrium behavior with the addition of extract

and/or polymer and determine temperature, pressure and

composition for the encapsulation processes. The shrimp

residue extract was obtained by cold maceration with ac-

etone. The phase equilibrium data were acquired using

the synthetic static method. Phase equilibrium data for

grape pomace extract with ethyl acetate and PLGA in CO2

are also being collected. Phase equilibrium data was ob-

tained for CO2 mass contents from 49.93 to 98.05% at

temperatures of 308 K, 313 K, 318 K and 333 K. The systems

exhibited liquid-vapor equilibrium with transition pres-

sures up to 9.38 MPa and a lower critical solution tem-

perature behavior. The increase in temperature caused an

increase in transition pressures.

ThE PhASE EqUILIBRIUM DATA OF COMPLEx SySTEMS AND A PRESSURIzED LIqUID ExTRACTION STUDy OF BRAzILIAN GINSENG (pfAffiA gLoMERATA) ECDySTEROIDS

289

ThE PhASE EqUILIBRIUM DATA OF COMPLEx SySTEMS AND A PRESSURIzED LIqUID ExTRACTION STUDy OF BRAzILIAN GINSENG (pfAffiA gLoMERATA) ECDySTEROIDS

isabel c. n. Debien, M. Angela A. MeirelesLASEFI/DEA/FEA (School of Food Engineering),



This doctoral project is being developed in two steps, in-

cluding the measurement of phase equilibrium data of

complex systems [1,2] and a pressurized liquid extraction

study of Brazilian ginseng (Pfaffia glomerata) ecdysteroids.

STEP 1

Biodegradable polymers have received increased

attention in recent years due to their potential applications

in the medicine and food industries, with significant focus

given to poly (L-lactic acid) (PLA) mainly because of its

biocompatibility and resorptive features. The synthesis of

this biopolymer by the enzyme-catalyzed ring-opening

polymerization of L-lactic acid in compressed fluids has

been considered a promising route. The aim of this work

is to report the relevant phase equilibrium data (cloud

points) of L-lactic acid + (propane + ethanol) and L-lactic

acid + (carbon dioxide + ethanol). Phase equilibrium ex-

periments were conducted in a variable-volume view cell

employing the static synthetic method, varying tempera-

ture from 323.15 K to 353.15 K and at pressures up to 25

MPa. The mass ratio of ethanol to CO2 or propane was held

constant at 1:9. For the (propane + ethanol) + L-lactic

acid, the sequence of vapor-liquid, liquid-liquid and vapor-


liquid-liquid was observed, while for (carbon dioxide +

ethanol) + L-lactic acid, only the sequence of liquid-liquid

type transitions were recorded. The results show that the

system of (propane + ethanol) + L-lactic acid presents

UCST (Upper Critical Solution Temperature) transition type

and an UCEP, whereas the system of (carbon dioxide +

ethanol) + L-lactic acid exhibits LCST behavior.

STEP 2

Species of the genus Pfaffia are popular substi-

tutes for Panax due to their similarities in morphology and

bioactive properties. Among them, Pfaffia glomerata has

received particular attention due to the presence of ec-

dysteroids. Commercially, this compound is obtained us-

ing conventional solid-liquid extraction methods, that is,

by using large quantities of solvents. Today, more envi-

ronmentally friendly methods are preferred, such as pres-

surized liquid extraction (PLE), which enables the rapid

extraction of bioactive compounds under high temper-

atures. The aim of this step of the work is to study the

pressurized liquid extraction of Brazilian ginseng (Pfaffia

glomerata) ecdysteroids. The effects of temperature (333-

393 K), pressure (8-30 MPa) and solvent [ethanol and eth-

anol:water (80:20 v/v)] on the global yield of extraction,

antioxidant activity and β-ecdysone content of the extracts

from Brazilian ginseng (Pfaffia glomerata) roots were stud-

ied. The global yield of extraction increased with the in-

crease in temperature, while pressure did not affect the

extraction yield. When ethanol was used as the solvent,

the global yields varied from 1.5% at 333 K to 5.0% at 393

K. For the mixture of ethanol:water, the global yields var-

ied from 7.5% at 333 K to 25.1% at 393 K. As the tempera-

ture increased, the selectivity of the solvent decreased,

promoting the co-extraction of other compounds in addi-

POSTERS 291

tion to the ecdysteroids. This behavior may explain the

slightly higher antioxidant activities observed for the ex-

tracts obtained at 333 K in comparison to those obtained

at 363 and 393 K when using ethanol as the solvent; ad-

ditionally, the pressure did not affect the response variable.

A similar behavior was observed for the mixture of etha-

nol:water; however, at 333 K, the antioxidant activities

increased from 8 to 20 MPa and then decreased. Further,

ethanol was found to be more selective for the extraction

of the ecdysteroids, where fractions containing up to 5 % of

β-ecdysone were obtained using this solvent at 393 K. Thus,

the better extraction condition for β-ecdysone was select-

ed (393 K, 8 MPa and ethanol as the extracting solvent),

and a kinetic extraction study was performed. After two

hours of extraction (S/F approximately equal to 48), the

raw material was not exhausted. However, the β-ecdysone

content did not increase significantly after one hour of

extraction. After, the commercial software SuperPro De-

signer® will be used to evaluate the economic viability of

the process [3].

ACKNOWLEDGMENTS

The authors acknowledge the financial support from CAPES (PROCAD 244/2007 and DEA/FEA/PROEX); partial support from FAPESP (2012/10685-8) is also acknowledged. I. C. N. Debien thanks CNPq (CNPq 151165/2010-6) for the Ph.D. assistantship. M. A. A. Meireles thanks CNPq for the produc-tivity grant (302778/2007-1).

REFERENCES

[1] I. C. N. Debien, A. A. Rigo, M. A. Mazutti, J. V. Oliveira, M. A. A. Meireles, High-pressure phase equilibrium data for the L-lactic acid+(propane+ ethanol) and the L-lactic acid+(carbon dioxide+ethanol) systems, J. Supercritical Fluids, 79 (2013) 27-31.

[2] I. C. N. DEBIEN, A. A. RIGO, M. A. MAZUTTI, J. V. OLI VEIRA, M. A. A. MEIRELES. High-pressure phase equilibrium data for the systems L-latic acid + (Propane + Ethanol) and L-latic acid + (Carbon dioxide + Ethanol). In: 10th International Symposium on Supercritical Fluids, 2012, San Francisco, CA, USA.


[3] I. C. N. DEBIEN, R. VARDANEGA, D. T. SANTOS, M. A. A. MEIRELES.

Optimization of pressurized liquid extraction of ecdysteroids from Bra-

zilian ginseng roots. In: III Iberoamerican Conference on Supercritical

Fluids, 2013, Cartagena das Indias.

UPDATING TRADITIONAL MEDICINE: NATURAL-BASED MEDICATED BIOMATERIALS FOR wOUND DRESSING APPLICATIONS USING GREENER PROCESSES

293

UPDATING TRADITIONAL MEDICINE: NATURAL-BASED MEDICATED BIOMATERIALS FOR wOUND DRESSING APPLICATIONS USING GREENER PROCESSES

Ana M. A. Dias, Mara E. M. Braga, hermínio c. de sousa

CIEPQPF – Chemical Engineering Departament, FCTUC, University of Coimbra;

Rua Silvio Lima, s/nº, Pólo II, Pinhal de Marrocos, 3030-790, Coimbra, Portugal;

E-mails: [email protected]; [email protected], [email protected]

Phytochemicals are biologically active chemical com-

pounds, naturally occurring in plants, where they act as

a natural defense system. They can be broadly classified

into major (g/100 g of plant material) and minor (microgram

to milligram range/100 g of plant material) constituents.

Major constituents include carbohydrates, lipids and pro-

teins while minor constituents include vitamins, minerals

and health beneficial secondary metabolites (phenolics,

terpenes, carotenoids, alkaloids, saponins, vitamins, pre-

and probiotics, bioactive peptides, etc). These metabolites

often present antioxidant, antimicrobial, anesthetic/stim-

ulant, anti-inflammatory, anticancer or antimalarial thera-

peutic capacities (among others), which justifies the wider

and common use of plants as medication tool in tradition-

al and complementary medicine worldwide. The World

Health Organization (WHO) supports traditional medicine

provided it proves to be efficacious and safe. According to

WHO reports, traditional medicines are estimated to be

used by 60% of the world’s population and in some coun-

tries are extensively incorporated into the public health

system. Some major categories of plant-derived products

include phyto-pharmaceuticals, herbal medicines, natural


health products, phyto-cosmetics and personal care prod-

ucts. The global demand for these products is increasing

due to a renewed interest of consumers for natural-based

products, since they are considered safer and more cost-

effective when compared to synthetic counterparts. Wound

healing is a specific health care area in which many plant-

derived products have been applied since ancient times

and this empirical knowledge still persists nowadays. Mod-

ern wound dressings are developed taking into consider-

ation three essential factors: that the dressing is able to

provide proper physiologic wound environment, to act as

a barrier for microorganisms and to stimulate healing. The

later can be enhanced by the impregnation of the dressing

with active substances like antibiotics, antimicrobial and/

or antiseptic agents to enhance the body’s own healing

mechanism. Over the last years our group has been working

on the development of medicated wound dressing mate-

rials using generally regarded as safe (GRAS) materials,

solvents and techniques. Our aim is to develop biocom-

patible and/or biodegradable biomaterials loaded with nat-

ural based bioactive compounds and using supercritical

fluid technologies (extraction and impregnation/deposi-

tion). These technologies are accepted as valuable alter-

natives to develop specialized materials for biomedical

applications, for which restrictive toxicity/biocompatibil-

ity limits have to be accomplished. Biomaterials tested so

far include agarose, chitosan (and several derivatives) and

mesoporous nanostructured silica while different natural-

based bioactive and/or plant extracts have been screened

for their antioxidant, anti-inflammatory and/or analgesic

bioactivity. These bioactive compounds include pure sub-

stance (such as quercetin, thymol and naphtoquinones)

and lipophilic extracts of jucá (Caesalpinia ferrea) or jambu

(Spilanthes acmella var oleracea) which are used in folk

POSTERS 295

medicine as natural anti-inflammatory and analgesic wound

healing agents, respectively. This work will present and

discuss the main results obtained so far and which include

natural extracts characterization, solubility of natural based

compounds in scCO2 and physical-chemical-biological

characterization of scCO2 loaded biomaterials according

to standard methodologies that permit to select those that

can be used as wound dressings (in terms of required po-

rosity, fluid handling capacity, hydrophilicity, cytotoxicity,

sustained release capacity and resilience).

ThE USE OF BIOREFINERy IN ThE AGRICULTURAL AND FOOD INDUSTRIES: hyDROLySIS AND GASIFICATION FOR BIO-hyDROGEN

297

ThE USE OF BIOREFINERy IN ThE AGRICULTURAL AND FOOD INDUSTRIES: hyDROLySIS AND GASIFICATION FOR BIO-hyDROGEN

Tania forster-carneiro, cristiana B. carneiro, M. Angela A. Meireles



Juliana M. pradoCTBE (Brazilian Bioethanol Science and Technology Laboratory),

CNPEM (Integrate Brazilian Center of Research in Energy and Materials); R. Giuseppe Máximo Scolfaro, 10.000, 13083-970, Campinas, SP, Brazil

Mauro BerniNIPE-Interdisciplinary Centre of Energy Planning,

University of Campinas (UNICAMP), SP, Brazil

A biorefinery is an industrial plant that fully utilizes raw

materials, sustainably, for the concomitant production of

food by-products with high added value and biofuels/en-

ergy. The organic residue recycling technologies used to

produce new products with energy recovery are emerging

as efficient and economically viable alternatives with sig-

nificant potential in terms of production and market value.

Brazil is recognized as a world leader in the export of food;

however, the industrial activities of the agri-food sector

generate significant amounts of organic waste. These res-

idues could become a major renewable resource for the

production of new chemicals, fuels and energy. There is

significant debate today regarding the environmentally

sound disposal of organic waste because, according to the

law n. 12.305 of 2010, such waste can no longer be final-

ly disposed in landfills. Sub/supercritical hydrolysis and

gasification are among these emerging technologies. Re-


cent research indicates that supercritical fluid technology

is economically viable when compared with thermal gas-

ification due to the high solubility of the biomass compo-

nents in supercritical water, which generates a cleaner gas

(no tar and pitch), as well as the highest concentration of

bio-hydrogen. The challenge of this technology is the op-

timization of the operating parameters involved in the pro-

cess to maximize the effects of temperature and pressure.

The use of gasification technology with supercritical wa-

ter presents significant advantages in comparison with

the thermal gasification processes already utilized in dry-

ing steps. With respect to gas production, recent studies

have shown that the primary gases produced during gas-

ification with supercritical water differ significantly from

the thermal gasification process: the gas produced is clean

(no tar), the hydrogen content is higher, dilution by nitro-

gen (N2) is not observed and the concentrations of carbon

monoxide (CO) and methane (CH4) are highly dependent

on the operational conditions. The complete conversion

of carbon is achieved after a relatively short residence

time, and significant amounts of CO are found in com-

parison with the low methane concentration. Further, bio-

hydrogen is produced directly at high pressures, which

means smaller reactor volumes and lower energy for pres-

surizing the gas in a storage tank are necessary. Currently,

the production of biogas is exploited industrially by fer-

mentation technology (biological treatment), and methane

gas is one of the vectors of renewable energy. However,

hydrogen gas (H2) is a clean gas and can be recycled. The

use of hydrogen incorporates technology that eliminates

the need for the deployment of new transmission lines,

because the conversion of electrical or thermal energy can

be performed on-site using the potential energy in small

spaces. The challenge of this work is the associated bio-

POSTERS 299

hydrogen production at lower temperatures (subcritical

conditions, 200-374 ºC). It is expected that the operating con-

ditions of the hydrolysis step, followed by gasification in

subcritical water, favor the production of bio-hydrogen;

the residence time is low due to the high solubility of the

components of cellulose biomass. The use of lower tem-

peratures represents a significant advantage, contributing

to reductions of investment and operating costs, as well

as maintenance. In this project, a new line of research is

proposed to develop new products with high value-added

technologies based on hydrolysis and gasification with

subcritical/supercritical water. Extensive tests (bio-hydrogen

and methane) with different operating parameters will be

needed, as well as the determination of gas composition

and assessments of the performance of different waste

types (soy, sugarcane, peanuts, palm fiber, coconut fiber,

grape seed and tomatoes wastes). This project proposes

the production of a clean gas with a high bio-hydrogen

concentration at lower temperatures (subcritical condi-

tions, 200-374 ºC), seeking to reduce the production costs

of sub/supercritical gasification at large scales. The assays

are performed in LASEFI/UNICAMP, which has adequate

infrastructure to achieve the proposed objectives of this

project. Specifically, the location possesses several units

for extraction and supercritical hydrolysis, most of which

were designed and tested in the laboratory, and can be

used with modifications to its configuration. The experi-

ments were performed in a semi-batch unit equipped with

a 50-ml reaction vessel was used for the SWH of raw ma-

terials (bagasse sugarcane, defatted grape seeds, pressed

palm fiber and coconut husk). Each sample was inserted

into the reactor, which was connected to the equipment,

and the experiments were carried out using 10-35 g of raw

material. Distilled water was pumped through the system


to remove residual air, and once the system was filled with

water, the pump was stopped, and the micrometric valve

was closed. The coil was heated, and the reactor was start-

ed. The heating coil temperature was set at the processing

temperature while the reactor was pre-heated to 120 ºC.

The temperature stabilized at approximately 20 min after

start, and the dynamic period of the process was started

by pumping water at 33 mL/min through the system for

30 min. When the dynamic period was initiated, the reac-

tor temperature was set to the processing temperature

(200 ºC or 250 ºC), leading to the development of a tempera-

ture profile over time until the temperature had stabilized.

The pressure was held constant at 20 MPa. Hydrolysate

samples were collected every 2 min. All experiments were

performed in duplicate. The hydrolysates were analyzed

by HPLC for their contents of 5-hydroxymethylfurfural (5-

HMF) and carbon-6 and carbon-5 (arabinose, fructose,

galactose, glucose, mannose, xylose, cellobiose and raffi-

nose). The preliminary results indicate that higher concen-

trations of sugars were obtained from sugarcane bagasse,

followed by fibrate coconut palm fiber and grape seeds.

The total sugars yielded and the liquefaction degree also

were obtained.

A STUDy OF ThE PARTICLE FORMATION OF ANNATTO ExTRACT USING SUPERCRITICAL FLUID TEChNOLOGy

301

A STUDy OF ThE PARTICLE FORMATION OF ANNATTO ExTRACT USING SUPERCRITICAL FLUID TEChNOLOGy

M. Thereza M. s. gomes, Diego T. santos*, M. Angela A. Meireles



*Industrial Energy Systems Laboratory (LENI), Swiss Federal Institute of Technology Lausanne (EPFL);

Station 9, CH-1015, Lausanne, Switzerland

Particle design using supercritical CO2 has received sig-

nificant interest over the past 20 years. Supercritical fluids

have been used as solvents, solutes, and antisolvents for

micro- and nanoparticle formation in a variety of com-

pounds and have overcome all of the limitations of tra-

ditional techniques. In an effort to increase the value of

extracts from annatto seeds, this study aims to coprecip-

itate annatto extract and polyethylene glycol (PEG) using

antisolvent processes, resulting in higher bioavailability

and enabling the protection of the unstable compounds

with respect to adverse conditions. The main pigments of

annatto seeds are bixin and norbixin, which are valuable

natural colorants. However, these seeds have acquired no-

toriety because they contain other important substances

for human health, such as tocopherols, tocotrienols and

geranylgeraniol. Due to the importance of these bioactive

compounds, for which recent studies have demonstrated

the protective effects of tocotrienols against neurodegen-

erative diseases, atherosclerosis and cancer, as well as their

antioxidant properties, obtaining these compounds was

the goal of this study. Thus, to add value to the δ-tocotrienol-


rich extracts obtained from annatto seeds using supercrit-

ical fluid extraction (SFE), we proposed the coprecipitation

of the annatto seed extract and a polymer using SAS

(Supercritical Antisolvent) and SFEE (Supercritical Fluid

Extrac tion of Emulsions) processes. First, a homemade

experimental apparatus was constructed by our research

group, and the apparatus was validated using a model

substance (Ibuprofen sodium salt). The effects of various

operating conditions (temperature, pressure, CO2 flow rate,

solution flow rate, injector type and concentration of ibu-

profen sodium in the ethanol solution) on the precipitation

yield, the energy consumption per unit of manufactured

product, the residual solvent content and particle mor-

phology were investigated using split-plot designs. Ibu-

profen sodium salt was successfully micronized by the SAS

process using the constructed unit. Then, SAS and SFEE

processes were applied to the ternary system of polyeth-

ylene glycol (PEG) + dichloromethane + annatto seed

extract to obtain dry coprecipitates and nanosuspensions,

respectively. The particle size, precipitation yield, residual

solvent content and morphology of the product as func-

tions of pressure, temperature, solution to antisolvent flow

rate and extract to PEG mass ratios are evaluated.

ACKNOWLEDGMENTS

The authors acknowledge the financial support from CNPq (564721-2010-7).

M. T. M. S. Gomes thanks CNPq (140641/2011-4) for the Ph.D. assistantship.

GREEN SOLVENTS FOR PRECISION CLEANING

303

GREEN SOLVENTS FOR PRECISION CLEANING

heather E. grandelli, phillip Maloney, Robert Devor, Jan surma, paul E. hintze

National Aeronautics and Space Administration; 870 Claytor Square, 24060 Blacksburg, VA, USA;


Aerospace machinery used in liquid oxygen (LOX) fuel

systems must be precision cleaned to achieve a very low

level of non-volatile residue (< 1 mg/0.1 m2), especially

flammable residue. Traditionally chlorofluorocarbons (CFCs)

have been used in the precision cleaning of LOX systems,

specifically CFC 113 (C2Cl

3F

3). CFCs have been known to

cause the depletion of ozone and in 1987 were banned by

the Montreal Protocol due to health, safety and environ-

mental concerns. This has now led to the development of

new processes in the precision cleaning of aerospace com-

ponents. An ideal solvent-replacement is non-flammable,

environmentally benign, non-corrosive, inexpensive, effec-

tive and evaporates completely, leaving no residue. High-

lighted is a ‘green’ precision cleaning process, which is

contaminant removal using supercritical carbon dioxide

as the environmentally benign solvent. In this process, the

contaminant is dissolved in carbon dioxide, and the parts

are recovered at the end of the cleaning process complete-

ly dry and ready for use. Typical contaminants of aerospace

components include hydrocarbon greases, hydraulic flu-

ids, silicone fluids and greases, fluorocarbon fluids and

greases and fingerprint oil. Metallic aerospace components

range from small nuts and bolts to much larger parts, such


as butterfly valves 18” in diameter. A fluorinated grease,

Krytox®, is investigated as a model contaminant in these

preliminary studies, and aluminum coupons are employed

as a model aerospace component. Preliminary studies are

presented in which the experimental parameters are op-

timized for removal of Krytox® from aluminum coupons

in a stirred-batch process. The experimental conditions

investigated are temperature, pressure, exposure time and

impeller speed. Temperatures of 308-423 K, pressures in

the range of 8.3-41.4 MPa, exposure times between 5-60

min and impeller speeds of 0-1000 rpm were investigated.

Preliminary results showed up to 86% cleaning efficiency

with the moderate processing conditions of 323 K, 13.8 MPa,

30 min and 750 rpm.

LIGNITE GASIFICATION IN SUPERCRITICAL WATER: KINETICS AND NUMERICAL STUDy (REVISED)

305

LIGNITE GASIFICATION IN SUPERCRITICAL WATER: KINETICS AND NUMERICAL STUDy (REVISED)

simao guo, Liejin guo, hui Jin, Zhiwei ge, youjun LuState Key Lab of Multiphase Flow in Power Engineering (SKLMF),

Xi’an Jiaotong University (XJTU);Xianning West Road 28# Xi’an, Sha’anxi, 710049, The People’s Republic of China;


Supercritical water gasification (SCWG) is a clean and ef-

ficient technology to convert lignite to hydrogen rich gas.

In order to know the quantitative rule of the lignite gasifi-

cation in supercritical water (SCW), this work proposed a

simplified reaction pathway for lignite gasification in SCW,

and developed a quantitative kinetics model for describing

production gases (H2, CO, CH

4, CO

2) yields. The kinetics

model contained seven typical reactions (pyrolysis, lique-

faction, steam reforming, methanation, water-gas shift

reaction) occurred in supercritical water gasification in-

cluding both homogeneous and heterogeneous reactions.

Apparent activation energy and frequency factor of each

reaction were obtained by fitting the experiments data

(5~25 wt% lignite slurry, 650~850 ºC, 13~120 s residence

time) using nonlinear least-square fitting method improved

by genetic algorithm. Then, the kinetics model was ap-

plied in a three-dimensional computational fluid dynam-

ics (CFD) model of a SCW fluidized bed reactor developed

by the State Key Laboratory of Multiphase Flow in Power

Engineering (SKLMF). The CFD model was established

for better understanding the complex physical and chem-

ical reaction phenomena of SCWG of lignite in the reactor,

and providing information for better reactor design /scale


up. By comparing the simulated results with experimental

data, the CFD model was validated. Based on the CFD

model, some valuable information such as the detailed

flow field, temperature distribution, chemical component

distribution and particles residence time distribution in-

side the reactor were obtained. The bottlenecks of com-

pletely gasification of lignite were pointed out. The effects

of the reactor wall temperature, preheated water tempera-

ture, lignite particle size and alkali catalysts on SCWG of

lignite were numerical investigated by the CFD model.

Moreover, several types of new reactor designs were eval-

uated by the CFD model, and the optimal design was pro-

posed for further SCW fluidized bed reactor development.

Finally, a comprehensive solution including both a new

designed reactor and its operating parameters for com-

pletely gasification of lignite in a moderate reaction tem-

perature condition was proposed. All these researches are

not only helpful to develop the technology of SCWG of

lignite, but also have theoretical values in other organics

(e.g. biomass, waste organics) gasification in SCW.

Key words: Supercritical Water Gasification (SCWG);

Lignite, Kinetics, Fluidized Bed Reactor; Numerical Study.

SUPERCRITICAL FLUID ExTRACTION FROM NATURAL PRODUCTS: AN OVERVIEW OF ThE MAThEMATICAL MODELING, SCALE-UP, SIMULATION AND ECONOMIC ANALySIS OF ThE PROCESS

307

SUPERCRITICAL FLUID ExTRACTION FROM NATURAL PRODUCTS: AN OVERVIEW OF ThE MAThEMATICAL MODELING, SCALE-UP, SIMULATION AND ECONOMIC ANALySIS OF ThE PROCESS

susana p. Jesus, M. Angela A. MeirelesLASEFI/DEA/FEA (School of Food Engineering),



Supercritical Fluid Extraction (SFE) is a high-pressure ex-

traction technique in which the solvent is a fluid (usually

carbon dioxide) in the supercritical state. It is a green tech-

nology that has been extensively studied in more than

three decades of intensive research. As a result, a solid

knowledge base of the fundamentals of SFE has already

been established, and significant amounts of experimen-

tal data are available in the scientific literature. The SFE

process has been applied on the commercial scale since

the 1980s [1]. Further, a wide number of industrial plants

of various capacities have been built during recent de-

cades. These operating plants are mostly distributed in

Europe, the USA, Japan, and in the South East Asian Coun-

tries [2]. However, in Brazil and many other countries, SFE

processes are not yet carried out on the commercial scale.

Therefore, SFE can still be considered an emerging tech-

nology because the conventional methods are the most

commonly used approaches in various applications of sol-

id-fluid extraction. In particular, this fact is the result of

the requirements of high-pressure processes, which ne-

cessitate higher investment costs in comparison to low-

pressure plants. Nonetheless, it is well known that several


other costs (in addition to investment costs) also must be

considered when estimating the cost of manufacturing

(COM) of some desired products [3].

Today, one of the crucial challenges in SFE inves-

tigation is to show that this process can be commercially

competitive in a variety of situations. Accordingly, special

attention must be given to the information that is required

for preliminary studies of process design and cost estima-

tion. The main goal of this work is to evaluate the calcu-

lation procedures used to obtain process design data that

may be applied in preliminary studies of economic feasi-

bility. For this purpose, some experimental data (available

from previous works performed by our research group) are

being used to investigate the mathematical modeling,

scale-up, simulation and economic analysis of the SFE

process.

First, the mathematical modeling of the overall ex-

traction curve (OEC) was studied, with focus on the ap-

plication of low-complexity models. The spline model, as

presented by Meireles [4], was successfully applied to

describe the kinetic data of SFE from rice bran oil soap-

stock. The results obtained are detailed in the recently

published work by Jesus et al. [5]. Second, a more complete

evaluation of the mathematical modeling of the OEC was

performed using the kinetic data from five different raw

materials (clove, ginger, grape seed, sugarcane residue,

and lemon verbena). The main purpose was to carry out

a comparison between the spline model [4] and the mod-

el developed by Sovová [6]. These models were evaluated

by considering the fitting performance (mean square error

and distribution of the residuals) and the applicability of

the adjusted parameters in terms of providing useful in-

formation for process design. A subsequent part of this

work will comprise some aspects of scale-up, simulation,

POSTERS 309

and cost analysis. Estimations of large-scale data will be

performed according to the scale-up criterion proposed by

Prado et al. [7] in a previous work from our research group.

The simulation of the SFE process on an industrial scale

and the economic analysis will be performed using the

commercial software SuperPro Designer® (Intelligen, Inc.,

USA).

ACKNOWLEDGEMENTS


PROEX). S. P. Jesus thanks CNPq (141828/2010-2) for the Ph.D. assistantship.

M. A. A. Meireles thanks CNPq for the productivity grant (302778/2007-1).

REFERENCES

[1] G. Brunner, Gas extraction: An Introduction to Fundamentals of Su-

percritical Fluids and the Application to Separation Process. 1. ed.,

Steinkopff; Darmstadt; 1994. 387 p.

[2] G. Brunner, Supercritical fluids: technology and application to food

processing, J. Food Engineering, 67 (2005) 21-33.

[3] P. T. V., Rosa, M. A. M. Meireles, Rapid estimation of the manufactur-

ing cost of extracts obtained by supercritical fluid extraction, J. Food

Engineering, 67 (2005) 235-240.

[4] M. A. A. Meireles, Extraction of bioactive compounds from Latin Amer-

ican plants. In: J. Martinez (Org.). Supercritical fluid extraction of nu-

traceuticals and bioactive compounds, Boca Raton: CRC Press – Taylor

and Francis Group, 2008, 243-274.

[5] S. P. Jesus, M. N. Calheiros, H. Hense, M. A. A. Meireles, A Simplified

Model to Describe the Kinetic Behavior of Supercritical Fluid Extraction

from a Rice Bran Oil Byproduct, Food and Public Health, 4(3) (2013)

215-222.

[6] H. Sovová, Rate of the Vegetable Oil Extraction with Supercritical CO2:

I. Modeling of Extraction Curves, Chemical Engineering Science, 3(49)

(1994) 409-414.

[7] J. M. Prado, G. H. C. Prado, M. A. A. Meireles, Scale-up study of su-

percritical fluid extraction process for clove and sugarcane residue, J.

Supercritical Fluids, 56 (2011) 231-237.

STUDy ON FURFURAL GASIFICATION ChARACTERISTICS IN SUPERCRITICAL WATER AND ITS REACTION PAThWAy

311

STUDy ON FURFURAL GASIFICATION ChARACTERISTICS IN SUPERCRITICAL WATER AND ITS REACTION PAThWAy

hui JinState Key Lab of Multiphase Flow in Power Engineering (SKLMF),

Xi’an Jiaotong University (XJTU);Xianning West Road 28# Xi’an, Sha’anxi, 710049, The People’s Republic of China;


Liquid fuel such as alkane and oxygenated fuel can be

produced from biomass depolymerization product, and the

process hydrogen is consumed. At the same time, a great

amount of by-products wastes production is inevitable, so

hydrogen production by supercritical water gasification

from the by-products wastes production makes this tech-

nology have more independence and better economy. How-

ever, publication about hydrogen production by supercritical

water gasification from by-products wastes from biomass

depolymerization is quite limited and the key hurdle pre-

vent furfural from complete gasification of the wastes is

still unknown and the optimal operational parameters. A

high throughput (6 channels) gasification apparatus is

established in State Key Laboratory of Multiphase Flow

in Power Engineering (SKLMF) for the supercritical water

gasification and furfural is selected as a model compound.

Temperature range of 400 ºC~700 ºC, pressure range of

25 MPa~40 MPa, reactor residence time of 0 minute ~ 20

minute, concentration of 2 wt% ~ 30 wt% were selected

for the exploration of the complete gasification condition.

The quantitative and qualitative analysis of the gaseous

products are operated by Gas chromatography/Mass spec-

tra and wet type gas meter. The main compounds of the


liquid products are analyzed by Gas chromatography/Mass

spectra and total organic carbon. The solid residual is an-

alyzed by scanning electron microscope and Fourier trans-

form infrared spectroscopy and Industrial analysis and

elemental analysis. A thermodynamics model based on

the Gibbs free minimization energy was proposed to show

the chemical reaction limit and to predict the products dis-

tributions. Equation of state of the mixing rule by Duan is

adopted. It is predicted that furfural can be gasi fied com-

pletely in supercritical water and the main gaseous prod-

ucts are hydrogen and carbon dioxide. A reaction kinetics

analysis is conducted to make clear the influence of the

key reaction path with the operating condition. It can be

concluded that the main intermediates are cyclopenta-

none, propionic acid and phenols. The research results

supplies the possibility of providing the optimal reaction

condition for the main reaction of furfural gasification in

supercritical water, retaining the side reaction and realiz-

ing the orientation gasification of furfural in supercritical

water.

TWO-PhASE FLOW ChARACTERISTICS IN SUPERCRITICAL wATER FLUIDIzED BED

313

TWO-PhASE FLOW ChARACTERISTICS IN SUPERCRITICAL wATER FLUIDIzED BED

youjun Lu, pengfei Zheng, Liping WeiState Key Lab of Multiphase Flow in Power Engineering (SKLMF),

Xi’an Jiaotong University (XJTU); Xianning West Road 28# Xi’an, Sha’anxi, 710049, The People’s Republic of China;


Supercritical water fluidized bed is a new reactor concept

for biomass gasification. Two-phase flow characteristics

in supercritical water fluidized bed have a significant effect

on the heat and mass transfer, contact between particle

and fluid, and chemical reaction. Firstly, an experimental

study on the hydrodynamics of a supercritical water flu-

idized bed was conducted. The frictional pressure drops

of a fixed bed and a fluidized bed were measured for a

temperature ranging from 633 to 693 K and pressure rang-

ing from 23 to 27 MPa. The results show that the Ergun

formula for calculating the frictional pressure drop of a

fixed bed can still be applied in supercritical water con-

ditions. The average deviation between Ergun formula and

experiment results is 13.3%. A predicting correlation for

the minimum fluidization velocity in a supercritical water

fluidized bed was obtained based on the experimental re-

sults of a fixed bed and the fluidized bed pressure drop.

The average error between the correlation and experiment

results was about 3.1%. However, experimental study is

still very difficult because of its severe operating condi-

tions in the SCW fluidized bed. Therefore, the two-phase

flow characteristics in the supercritical water fluidized bed

have been studied with Discrete Element Method, in order


to provide theoretical basis for design and structure opti-

mization of a supercritical fluidized bed reactor. The drag

model provided by Wen & Yu (1966), Gidaspow (1987), and

Syamlal & O’Brien (1989) were evaluated through mod-

eling the bed expansion, solid particle velocity, and bed

pressure drop, and minimum fluidization velocities of SCW

fluidized bed. In simulation, the density and viscosity of

SCW fluid were 283.79 kg/m3 and 3.67×10-5 Pa∙s, and the

density and diameter of particles were 2580 kg/m3 and

0.5 mm. Based on the simulation results, both Gidsapow

and Syamlal & O’Brien drag models predicate similar bed

expansion height, pressure drop, and particle velocities

distribution. Comparing to Gidsapow drag model and

Syamlal & O’Brien drag model, Wen & Yu drag model pred-

icates higher bed expansion height and higher pressure

drop when u/umf<1.2, but lower bed expansion height

when u/umf 1.2. The deviation of minimum fluidization

velocity between simulations and experimental results

were with 2.85% for Gidsapow drag model and Syamlal &

O’Brien drag model, but 8.75% for Wen & Yu drag model.

Therefore, it is suitable to simulate SCW fluidized bed by

using Gidsapow drag model or Syamlal & O’Brien drag

model. The huge divergences of two-phase flow character-

istics in SCW fluidized bed and in gas-solid fluidized bed

can be found by comparisons of bed pressure drop, average

particle height and bubble characteristics. The density and

viscosity of gas used in present study are 0.33 kg/m3,

and 2.38×10-5 Pa∙s. When superficial velocity was above

the minimum fluidization velocity, the amplitude of pres-

sure drop of gas-solid fluidized bed is greater than that of

SCW fluidized bed. The bed pressure drop power spectrum

analysis shows that the dominant frequency is 2.8 Hz for

SCW fluidized bed, but 3.2 Hz for gas-solid fluidized bed,

which indicates a stronger bubble collision ratio, coales-

POSTERS 315

cence, and break open in gas-solid fluidized bed. The

number and size of bubbles in gas-solid fluidized bed is

greater than that in SCW fluidized bed at the same bed

height level. Also, the effect of superficial velocity, tem-

perature and pressure on bubble amount, bubble size and

bubble velocity is revealed respectively in SCW fluidized

bed. The results in this paper are useful for the design of

SCW fluidized bed.

SUPERCRITICAL DESORPTION OF CAROTENES FROM ALUMINA ADSORBENTS

317

SUPERCRITICAL DESORPTION OF CAROTENES FROM ALUMINA ADSORBENTS

M. A. E. cunha, A. L. santana, c. f. M. Batista, f. f. M. Azevedo, M. E. Araújo, n. T. Machado

Laboratory of Separation Processes and Applied Thermodynamic, Faculty of Chemical Engineering (UFPA);

Rua Augusto Corrêa, 1, 66075-900, Belém, Pará, Brazil; E-mail: [email protected]

Buriti (Mauritia flexuosa, Mart), a native palm growing in

swamps and flooded areas along rivers and forests on the

Amazon region, is one of the palms with the highest eco-

nomic potential because its oil is a rich natural source of

pro-vitamin A. The fruits of Buriti have a soft and oily

dark-yellow to reddish pulp, containing between 20-30%

(wt.) of a reddish oil with the highest concentration of

carotenes in vegetable oils, with an estimate annual av-

erage oil specific production of 57.5 ± 17.0 kg.ha-1, having

a great economic potential of application in the food and

cosmetic industries because of its effectiveness on the

treatment and prevention of diseases caused by deficien-

cy in vitamin A, use as natural plasticizer for starch, ab-

sorption and photoluminescence optical properties, low

cytotoxicity in creams and lotions formulations, and pho-

toprotective properties against UVA and UVB irradiation

on cells. Since the pioneer work of Model et al., supercrit-

ical carbon dioxide has been applied on desorption of syn-

thetic chemicals (e.g. phenol, ethyl acetate, benzene, toluene,

naphthalene, phenanthrene, hexachlorobenzene, penta-

chlorophenol, and isomeric dimethylnaphthalene mixtures,

DDT, n-hexane, methyl ethyl ketone, and toluene, ethyl

acetate and furfural, m-xylene, benzoic acid or salicylic


acid), essential oils (e.g. lemon, bergamot, mandarin, lime

and bitter orange oil), and even fat-soluble substances from

vegetable oils (carotenes, β-carotenes, tocopherol acetate,

α-tocopherol), loaded in different adsorbents (e.g. silica

gel, aluminum oxides, γ-alumina, activated carbon, cellu-

lose, bentonite, magnesium silicate, and zeolite), as report-

ed in the literature. Despite the development of several

processes to recover and concentrate carotenes from veg-

etable oils by traditional methods, particularly crude palm

oil, degummed palm oil, palm fatty distillates and refined,

bleached and deodorizer palm oil reported in the literature,

only a few works have been reported concerning the ap-

plication of supercritical adsorption/desorption processes

to recover and/or enrich carotenes from vegetable oils, in-

cluding batch adsorption of crude palm oil in stirred tanks

followed by supercritical desorption, supercritical adsorp-

tion of Buriti oil (Mauritia flexuosa, Mart) related com-

pounds in γ-alumina adsorbent using carbon dioxide. In

this work, enriching of carotenes has been systematically

investigated by supercritical desorption process. The de-

sorption of carotenes from preparative columns packed

with γ-alumina adsorbents loaded with Buriti oil has been

determined experimentally at 20 and 25 MPa, 333 K, and

solvent flow rate of QCO2 = 10.6 l/min, using a high pres-

sure apparatus with a jacket autoclave (Mechanical Work-

shop, TUHH-Germany) of 1000 cm³, adapted to be used as

a desorption cell by assembling 01 (one) cylinder of 2.7 cm

internal diameter and 14.25 cm height inside the high

pressure vessel of 1000 cm³, a diaphragm-type compressor

(Andreas Hofer Hochdrucktechnik GmbH, Model: MKZ

120-50), a sampling system with a separator of 130 cm³

(Mechanical Workshop, UFPA-Brazil), a thermostatic bath

(Haake Mess-Technik GmbH, Model N3), a carbon dioxide

reservoir and a gas meter. Buriti oil has been characterized

POSTERS 319

according to the following AOCS official methods: AOCS

Cd 3d-63, AOCS Cd 3-25, AOCS Cd 8b-90, AOCS Cd-1.25,

and AOCS 940.28 [42], Refraction Index by adjusting the

Abbé Refractometer with distilled water (IR 20 ºC = 1.333),

density at 313 K, viscosity according to ASTM 446 and

ASTM D 2515 methods using a Cannon-Fenske viscosim-

eter, (Capillary tube Nº. 200) and carotenes by UV-VIS

spectrophotometry and HPLC. The fixed bed containing

γ-alumina loaded with Buriti oil has been characterized

in terms of height (m), internal diameter (m), adsorbent

equilibrium capacity (g/kg), particle diameter (A), particle

porosity (-), fixed bed porosity (-), CO2 interstitial velocity

(m/s), and adsorbent density (kg/m³). The mass transfer

models of Tan and Liou and Brady et.al have been applied

to describe the kinetic behavior of supercritical desorption

process. The influence of pressure and adsorbent capacity

on the supercritical desorption processes has been inves-

tigated by analyzing the mass transfer performance. The

solubility of Buriti oil in supercritical carbon dioxide has

been computed by linear adjust of desorption kinetic by

determining the final point of the linear part of desorption/

extraction curve. A computational algorithm code written

in EXCEL using the build in function PROJ.LIN has been

used to calculate the period of constant extraction rate,

the mass transfer rate for the period of constant extraction

rate and the solubility. This spreadsheet calculator gen-

erates a graphic that shows automatically the splines of

both straight lines describing the periods of constant and

decreasing extraction rate being adjusted. A 2.5 fold en-

riching of carotenes has been obtained by integrated su-

percritical adsorption/desorption of Buriti oil fat soluble

compounds in γ-alumina adsorbent using carbon dioxide

as solvent, posing this methodology as an alternative meth-

od for the enrichment of carotenes from vegetable oils.

CARBON DIOxIDE CAPTURE AND UTILISATION FOR ENERGy GENERATION AND COMPOSITE MATERIALS

321

CARBON DIOxIDE CAPTURE AND UTILISATION FOR ENERGy GENERATION AND COMPOSITE MATERIALS

fabricio c. Marques, neil Rowson, peter J. hammond, Regina c. D. santos

University of Birmingham;Edgbaston, B15 2TT, Birmingham, West Midlands, UK;


There is growing agreement that anthropogenic emission

of greenhouse gases like carbon dioxide (CO2) have led to

global warming and climate change on a global scale,

which are having dire consequences for the Earth’s eco-

system. Fortunately there are many technologies that can

capture CO2. Nevertheless, most processes propose storing

it underground, which requires a very large infrastructure

that is costly and energy-intensive, not to mention other

negative impacts on the environment. In addition large

quantities of CO2 can be released back to the atmosphere

if naturally-occurring phenomena or accidents occur. As

a result, a novel process has been developed in conjunc-

tion with industrial partner CCm Research Ltd., where

eco-friendly cellulosic-based biomass is functionalised

with amine compounds that effectively chemisorb CO2 in

an exothermic reaction and convert it to a stable carbon-

ate form (R-CO3). The carbonate structure has been con-

firmed with FTIR and SEM, and the reaction mechanism

and thermal stability of the material have been studied

with a simultaneous thermal analyser using a TGA-DTA

connected to an FTIR for evolved gas analysis. One appli-

cation of this material has been tested, where it was com-

pounded in an extruder with polymer to form a strong,


lightweight composite material. The physical and chem-

ical properties of the composite were determined with a

mechanical tester, a gas pycnometer and the TGA-DTA-

FTIR system. The activation energy for composite decom-

position was generally found to be double that of pure

polymer, thus resulting in a material with higher thermal

stability. Moreover, any CO2 in carbonate form encapsulat-

ed within the polymer was only released upon decomposi-

tion at temperatures above the composite’s melting point,

thus effectively increasing its thermal stability more than

twofold. Composites containing high levels of CO2-loaded

biomass displayed values of yield stress and elasticity

modulus that indicate the composite can be applied in

several areas where polymers are commonly used, e.g.

packaging, furniture, automobiles, construction, etc. There-

fore a method to capture and utilize CO2 was demonstrat-

ed, which avoids the high costs and logistics associated

with storage underground. This new material is very prom-

ising because of its CO2 capture effectiveness, simple pro-

duction process, low energy consumption and relatively

low cost. Ultimately this process is sustainable and can

be commercialised, thus generating economic and envi-

ronmental benefits at the same time.

INVESTIGATIONS ON SUPERCRITICAL TRANSESTERIFICATION OF VEGETABLE OILS AND ANIMAL FATS FOR BIODIESEL PRODUCTION AT TEMPERATURES 300-400 ºC AND 9:1-15:1 ALCOhOL MOLAR RATIOS

323

INVESTIGATIONS ON SUPERCRITICAL TRANSESTERIFICATION OF VEGETABLE OILS AND ANIMAL FATS FOR BIODIESEL PRODUCTION AT TEMPERATURES 300-400 ºC AND 9:1-15:1 ALCOhOL MOLAR RATIOS

victor fernando MarulandaUniversidad de La Salle;

Cra 2 # 10-70, 57, Bogota, Cundinamarca, Colombia; E-mail: [email protected]

Supercritical transesterification has been proposed as an

alternative to the conventional base catalyzed process for

biodiesel production due to its apparent advantages re-

lated to the feasibility to use cheaper triglyceride feed-

stocks, and a simpler process resulting of the elimination

of the use of a catalyst in the final product purification. In

this aspect, most of the experimental studies have been

carried out at temperatures 300-350 ºC and alcohol to oil

molar ratios higher than 40:1, higher temperatures have

been associated to a deterioration of the fuel quality. More

recently, several studies have been conducted at tempera-

tures around 400 ºC and lower reactant ratios. Though

initially focused on improving economic and environmen-

tal performance indicators of the supercritical process, the

experimental results have shown the high temperature

promotes several reactions of decomposition of long chain

esters and glycerol into short chain esters and glycerol

ethers, which have the potential to improve certain prop-

erties of the fuel such as viscosity and cold flow. In this

work the experimental results of the batch and continuous

supercritical transesterification of chicken fat, bovine fat

and crude palm oil with methanol and ethanol at tem-

peratures 300-400 ºC and 9:1-15:1 alcohol molar ratios are


discussed. Qualitative as well as quantitative product anal-

ysis by GC-MS indicates a conversion of triglycerides near

to completion at 400 ºC and residence times of 12, 15 and

30 minutes for chicken fat, crude palm oil and bovine fat,

respectively. The different times can be associated to the

alcohol used in the transesterification, methanol or etha-

nol, the first one being more reactive, and the triglyceride

composition of the raw material. Short chain methyl esters

as well as linear hydrocarbons not initially present in the

raw material were identified in the produced biodiesel.

Though short chain esters have lower boiling points and

viscosities than the longer ones, which positively affect

the product, the cetane number is lower. However hydro-

carbons have a higher cetane number that could make up

for the apparent reduction or deterioration of the fuel qual-

ity. Glycerol ethers, resulting from methylation/ethylation

reactions of glycerol were also identified in the product.

Some of these products remained in the biodiesel phase

and could act to improve certain properties of the fuel or

be considered fuel additives. In this aspect, the studied

supercritical process could offer a feasible technical alter-

native to the glycerol byproduct, currently considered a

waste problem for the biodiesel process due to the high

cost of its purification and low prices in the market.

PRECIPITATION AND ENCAPSULATION OF BIOACTIVE COMPOUNDS USING SUPERCRITICAL TEChNOLOGy

325

PRECIPITATION AND ENCAPSULATION OF BIOACTIVE COMPOUNDS USING SUPERCRITICAL TEChNOLOGy

natália Mezzomo, sandra R. s. ferreiraFederal University of Santa Catarina (UFSC), EQA/CTC; CP 476 – Trindade, 88040-900, Florianópolis, SC, Brazil;


Natural products are relevant sources of compounds with

biological activity, which are technologically important for

employment in chemical, pharmaceutical and food indus-

tries. The growing interest of these industries in natural

extracts foments researches of their recovery using tech-

nologies that allow high quality production. Due to the

molecular structure and high unsaturation rate of these

compounds, factors like heat, light and presence of acids

cause their isomerization, with loss and/or diminution of

the biological properties. Thus, aiming at industrial appli-

cation of these extracts, the study of methods enabling

their stabilization, as encapsulation in polymers, is im-

portant. The objective of this project is to study the encap-

sulation of bioactive extracts through the processes of

Supercritical Anti-Solvent (SAS) and Supercritical Fluid

Extraction of Emulsions (SFEE), seeking the production

of stable micro/nano-particles. For both methods applica-

tion, a flexible unit that can be used for Supercritical Fluid

Extraction (SFE), SAS and SFEE is being executed. The

evaluation of SAS unit is being performed throughout the

precipitation of sodium ibuprofen, a well-known nonste-

roidal anti-inflammatory drug considered model material

for crystallization processes. The primary solvent used was

acetone and the anti-solvent applied was supercritical CO2.


The following ranges evaluated the SAS process: pressure

(80-140 bar), temperature (35-55 ºC ), solute concentration

(0.5-1.5 mg/mL), solution flow rate (1-3 mL/min) and con-

stant CO2 flow rate of 1 kg/h. The particles obtained from

all conditions were evaluated by their size and morphol-

ogy, using a scanning electronic microscopy (SEM), the

thermal profiles by differential scanning calorimetry (DSC),

and the crystallinity using x-ray diffraction (XRD). The av-

erage particle sizes of the SAS-precipitated ibuprofen were

below 380 ± 84 nm for all the conditions tested in the

experiments, which means that the size of the original

particles was reduced from micrometric (non-processed

sodium ibuprofen) to nanometric order (SAS particles). The

best SAS operational conditions, in order to produce the

lowest ibuprofen particle size, were 0.5 mg_ibuprofen/mL,

1 mL_solution/min, 1 kg_CO2/h, 110 bar and 35 ºC. Besides

reducing the ibuprofen particle size, the SAS process ap-

pears to have purified the original sodium ibuprofen, accord-

ing to the thermal analysis of processed and non- processed

ibuprofen particles. The XRD results indicated that SAS

process at 1 mg_ibuprofen/mL, 1 mL_solution/min, 1 kg_

CO2/h, 110 bar and 35 ºC are the best conditions to obtain

ibuprofen particles with higher crystallinity. The sequence

of the project is the SAS study applied to natural extracts

encapsulation. It is being studied the SAS encapsulation

of extract from grape pomace in poly(lactic-co-glycolic)

acid (PLGA), varying the operational variables (pressures

of 80-140 bar temperature of 35-45 ºC, solution flow rate of

1-3 mL_solution/min, constant CO2 flow rate of 1 kg_CO

2/h),

and verifying their influence in the quality of particles

produced (particle size and shape by SEM analysis, inter-

action between encapsulant and encapsulated materials

through the DSC). The future project activities are to adjust

the SFE/SAS unit to the SFEE process and apply it to nat-

ural extracts encapsulation.

327

IDTq — A NEW RESEARCh GROUP LOCATED IN CORDOBA, ARGENTINA: PhASE EqUILIBRIUM AND ITS APPLICATION TO IMPREGNATE BIOPOLyMERS AND TO DESIGN DRUG DELIVERy SySTEMS

Juan M. Milanesio, Alfonsina E. Andreatta* IDTQ – Grupo Vinculado PLAPIQUI – CONICET – FCEFyN,

Universidad Nacional de Córdoba; Av. Vélez Sarsfi eld 1611, Córdoba, Argentina

* Facultad Regional San Francisco, Universidad Tecnológica Nacional;

Av. de la Universidad 501, San Francisco, Córdoba, Argentina

cesar gomez, Miriam striumiaDepartamento de Química Orgánica,

Facultad de Ciencias Químicas, Universidad Nacional de Córdoba;

Haya de la Torre y Medina Allende, Edifi cio de Ciencias II, Ciudad Universitaria, Córdoba, Argentina

Lidia QuinzaniPLAPIQUI – Planta Piloto de Ingeniería Química,

Universidad Nacional del Sur – CONICET, Cno.;La Carrindanga km. 7, Bahía Blanca, Argentina;


IDTQ is a recently developed research group with a high

potential and mainly focused on supercritical technology

applied to the extraction of natural products and its use

on human health, and also applied to solve energy problems.

Also, the extracted bioactive compounds are being

studied to develop new drug delivery systems using poly-

mers with supercritical technology. The synthesis of polymers

from glycerol or its derivatives and their application to de-

velop controlled release drug delivery systems are one of

the main interests in our research group.

Plants with important properties for human health

accompany mankind from its origins. In spite of the great

evolution of health sciences, pathologies still exist without


a definitive cure or with therapies that cause undesirable

effects. Within this frame it is necessary to search new

therapeutic agents.

Glycerol is a polyfunctional molecule, with three

alcohol groups and with a high reactivity and versatility

[1]. Using esterification reactions it is possible to develop

new polymers with surfactant properties [1]. These poly-

mers, with a hydrophilic and a hydrophobic region, can

be used for drug encapsulation [2-5] using supercritical

technology for particle precipitation [6]. Particularly, they

can be used as carriers for highly hydrophobic drugs inside

micelles, like cancer chemotherapy drugs [2, 4-5]. In this

work we will present preliminary results for the synthesis

of polymers via glycerol esterification and from glycerol

carbonate, and its application for designing controlled

release drug delivery systems. Within the scope of these

preliminary results are phase equilibrium data for glyc-

erol, carbon dioxide and the polymers.

REFERENCES

[1] C. H. Zhou, J. N. Beltramini, Y. X. Fan, G. Q. Lu, Chemoselective cat-

alytic conversion of glycerol as a biorenewable source to valuable

commodity chemicals, Chemical Society Reviews, 37 (2008) 527-549.

[2] M. E. Fox, F. C. Szoka, J. M. J. Fréchet, Soluble polymer carriers for

the treatment of cancer: The importance of molecular architecture,

Accounts of Chemical Research, 42 (2009) 1141-1151.

[3] J. Green, Z. Tyrrell, M. Radosz, Micellization of poly(ethylene glycol) -

block-poly(caprolactone) in compressible near critical solvents, J. Phys-

ical Chemistry C, 114 (2010) 16082-16086.

[4] L. Y. Lee, S. H. Ranganath, Y. Fu, J. L. Zheng, H. S. Lee, C. H. Wang,

K. A. Smith, Paclitaxel release from micro-porous PLGA disks, Chem-

ical Engineering Science, 64 (2009) 4341-4349.

[5] Z. L. Tyrrell, Y. Shen, M. Radosz, Multilayered nanoparticles for con-

trolled release of paclitaxel formed by near-critical micellization of tri-

block copolymers, Macromol, 45 (2012) 4809-4817.

[6] S. D. Yeo, E. Kiran, Formation of polymer particles with supercritical

fluids: A review, J. Supercritical Fluids, 34 (2005) 287-308.

COMPRESSED GASES FOR ThE SEPARATION OF BIOMASS FROM IONIC LIqUID MIxTURES

329

COMPRESSED GASES FOR ThE SEPARATION OF BIOMASS FROM IONIC LIqUID MIxTURES

David L. Minnick, Aaron M. scurtoDepartment of Chemical & Petroleum Engineering

and Center for Environmentally Benefi cial Catalysis, University of Kansas;

5234 Eisenhower Terrace, 66049, Lawrence, Kansas, USA;E-mail: [email protected]

Identifying cost-effective renewable energy sources is vi-

tal as the world continues to experience a strain on fossil

fuels. Cellulose, the world’s most abundant natural bio-

polymer, presents an inexpensive, carbon-neutral feedstock

for the production of bio-fuels and bio-chemicals. Howev-

er, the rigid hydrogen bonding network between cellulose

molecules renders it insoluble in nearly all organic solvents.

Select ionic liquids (ILs) including 1-butyl-3-methylimidaz-

olium chloride [BMIm][Cl] and 1-ethyl-3-methylimidazolium

diethyl phosphate [EMIm][DEP] are capable of dissolving

significant quantities of cellulose. Once dissolved the cel-

lulose can undergo one of two routes: 1) direct conversion

to glucose via hydrolysis or 2) precipitation. In the first pro-

cess, cellulose derivatization results in monomeric glucose

subunits that can be used for energy, or further processed

into high-value chemicals. Alternatively, precipitating the

cellulose out of the IL yields a less-crystalline, pre-processed

form with a wide range of applications. Regardless of the

desired end product, an extraction technique must be

performed to separate the final product and ionic liquid.

Anti- solvent methods have been proposed whereby large

quantities of anti-solvent are mixed with the IL solution

to crystallize the product, resulting in solid-liquid phase


equilibria (SLE). While effective, the excessive quantities

of anti-solvent required to separate cellulose and glucose

from ionic liquids negatively impacts the feasibility of these

processes from sustainability and economic standpoints.

Here we propose a competing process to selectively re-

move cellulose and glucose from ionic liquids using com-

pressed CO2 by altering the phase behavior of these systems.

For the IL:glucose system, two extraction methods have

been observed. First, CO2 at moderate pressure is capable

of converting this system from vapor-liquid equilibria (VLE)

to vapor-liquid-solid equilibria (VLSE) phase behavior, thus

precipitating the pure glucose product for separation by

filtration. Second, high pressure CO2 can transform certain

IL/glucose/solvent systems from vapor-liquid equilibria

(VLE) to vapor-liquid-liquid equilibria (VLLE) phase behav-

ior where glucose is extracted into the organic or aqueous

(non-IL) liquid phase for separation. These same process-

es are applicable to the separation of cellulose from ILs

and will be demonstrated. Compressed carbon dioxide is

a promising alternative to conventional organic anti-sol-

vents for extracting glucose and cellulose from ionic liq-

uids. Our results will display how high pressure CO2 can

alter the phase behavior of these systems and the result-

ing glucose/cellulose separations.

OBTAINING ExTRACTS FROM CLOVE (EugEniA cARyophyLLus) AND ANNATTO (BixA oRELLAnA L.) USING SUPERCRITICAL FLUID ExTRACTION IN A CONTINUOUS OPERATING MODE

331

OBTAINING ExTRACTS FROM CLOVE (EugEniA cARyophyLLus) AND ANNATTO (BixA oRELLAnA L.) USING SUPERCRITICAL FLUID ExTRACTION IN A CONTINUOUS OPERATING MODE

Moyses n. Moraes, giovani L. Zabot, M. Angela A. Meireles



The goal of obtaining increasingly natural products of high

purity is leading researchers to use more suitable extrac-

tion processes, known as “green processes”. Thus, super-

critical fluid extraction (SFE) is receiving increased attention,

because it is a green technology that yields distinct ex-

tracts relative to those obtained in the conventional extrac-

tion processes. The resulting SFE waste, which is considered

a better co-product, is the vegetal matrix, free of target

compounds; the matrix can be used as the raw material

for other integrated processes. The maximum utilization

of raw materials is a current subject in interest. Likewise,

the productivity of a process can be improved by incorpo-

rating the continuous extraction of bioactive compounds.

Understanding the influence of various parameters on the

continuous extraction process is the target for implementing

the supercritical technology on an industrial scale. The ex-

traction time, the amount of solvent, the shape of the

extractors and the characteristics of the raw materials are

some of the parameters known to influence the techno-

economic aspects of such processes. Further, the use of a

range of extraction vessels is necessary to accomplish the

operation. In this sense, we assembled an apparatus with

two one-liter extractors to obtain two extracts in continu-


ous mode using supercritical CO2, including (1) a volatile

oil from clove buds and (2) an extract rich in tocotrienols

from annatto seeds. These two vegetal matrices were se-

lected because they contain volatile oil and pigments with

health benefits, which are in high demand in the global

market. The high quantity of bixin in the annatto extracts

allows for strong colorant action. Additionally, both raw

materials can be used, after extraction, in the hydrolysis

of the lignocellulosic structure for producing fermentable

sugars. In this context, the proposed system was found to

be efficient because it was possible to reach significant

extraction yields in short times in comparison to batch

processes. When one extractor was in the charge/discharge

step, the other was used for extraction, which allowed the

product to be continuously obtained. Based on laboratory

experiments, some parameters were defined as suitable

parameters for use in the continuous mode. For clove oil

(1), the ideal CO2 mass to feed mass (S/F) was approxi-

mately 1.9 (corresponding to 60 min of extraction and 80 g

of extract/100 g of extractable). For the annatto extract (2),

the ideal S/F was approximately 2.7 (corresponding to 90

min of extraction and 66 g of extract/100 g of extractable).

From the economic perspective, the use of supercritical

CO2 extraction in a continuous mode reduces the payback,

which is the time needed to match the net profit with the

initial amount of capital invested.

ACKNOWLEDGEMENTS


PROEX); partial support from FAPESP (2009/17234-9 and 2012/10685-8)

is also acknowledged. M. N. Moraes thanks CAPES and G. L. Zabot thanks

FAPESP (2011/23665-2) for the Ph.D. assistantships. M. A. A. Meireles


ESTIMATION OF COSTS IN SUPERCRITICAL CO2 ExTRACTION PLANTS OF SOLID SUBSTRATES By SIMULATION PROCESS

333

ESTIMATION OF COSTS IN SUPERCRITICAL CO2 ExTRACTION PLANTS OF SOLID SUBSTRATES By SIMULATION PROCESS

gonzalo A. núñez, José M. del valleUniversidad Técnica Federico Santa María;

Av. Vicuña Mackenna 3939 San Joaquín, Santiago, Chile;E-mail: [email protected]

Supercritical fluid extraction of solid substrates has been

applied commercially for a long time to several applica-

tions (including extraction of hops, decaffeination of coffee

beans, extraction of flavors from herbs and spices, extrac-

tion of oilseed, among others). Despite of this, in literature

there is little information about scaling-up and costing of

this technology, which generally is part of the know-how

of plant manufacturers. The objective of this work (based

on the doctoral thesis titled “Development of a Simulation

Tool for the Economic Optimization of an Extraction Plant

for Vegetable Substrates Using Supercritical CO2”) is to

present a simulation tool to estimate the costs in an in-

dustrial supercritical CO2 extraction plant and to show the

effect of relevant parameters in the extraction process.

Particularly, this work presents estimates for operational

and production costs of the supercritical CO2 extraction

of prepressed oilseeds using a novel simulation algorithm

based on the fully predictive shrinking core model for the

inner mass transfer. Operational costs (<9 USD/kg of oil)

decrease when particle size decreases and superficial CO2

velocity increases. Production costs (estimated <13 USD/

kg of oil) include the capital cost, which is one of the items

with major uncertainties in the estimates. Under the same

extraction conditions, a decreasing of the aspect ratio (L/D)


of the extraction vessels has a positive effect on production

cost. In two-vessel plant, the lowest production cost was

reached at highest extraction pressure (70 MPa). However,

in multi-vessel plants, the minimum production cost was

at 50 MPa. In all cases studied, the number of extraction

vessels and the total volume of the plant had a positive

effect on production cost, confirming that economies of

scale apply to this process. Other factors as optimal ex-

traction time, exhaustion grade of the substrate, and pro-

ductivity of the plant should be taken in count to make

decisions about investment or to optimize the operation

of an industrial plant. Finally, the methodology developed

in the thesis can be adapted to others solid substrates

using a proper mass transfer model. This work will present

the adaptation of the simulation tool to the extraction of

tomato with supercritical CO2 using the Desorption-Dis-

solution-Diffusion (DDD) mass transfer model with a Fre-

undlich isotherm to describe the partition of the solute

between the solid matrix and the supercritical phase.

OVERVIEW OF ThE hIGh PRESSURE TEChNOLOGy AND NATURAL PRODUCTS LABORATORy OF ThE UNIVERSITy OF SãO PAULO IN DEFENSE OF ThE TEChNOLOGICAL INNOVATION

335

OVERVIEW OF ThE hIGh PRESSURE TEChNOLOGy AND NATURAL PRODUCTS LABORATORy OF ThE UNIVERSITy OF SãO PAULO IN DEFENSE OF ThE TEChNOLOGICAL INNOVATION

Alessandra L. oliveiraDepartamento de Engenharia de Alimentos (ZEA),

Faculdade de Zootecnia e Engenharia de Alimentos (FZEA); Avenida Duque de Caxias Norte, 225, 13635-900, Pirassununga, SP, Brazil;


The High Pressure Technology and Natural Products Lab-

oratory (LTAPPN ) is a new research laboratory of the Food

Engineering Department, Faculty of Animal Science and

Food Engineering of the University of São Paulo. Created

in 2003 under the responsibility of Prof. Dr. A.L. Oliveira,

it conducts physical separations research employing high-

pressure systems. Initial work was aimed to study the

separation extracts rich in active compounds from natural

Brazilian flora (Guaco, Pitanga fruit) using supercritical

CO2 and thermodynamic modeling of the solubility of these

compounds in this supercritical solvent using equations

of state. Currently, the work continues to be developed

for this purpose, using separation processes with super-

critical fluid (SFE) and pressurized liquid extraction (PLE)

with pressurization by means of nitrogen. The modeling

of separation processes continues to be practiced using

equations of state for the solubility study and numerical

simulation in transport phenomena. Research are direct-

ed to extraction optimization of Pitanga seeds, flour from

Babaçu mesocarp and Pequi, characteristic fruit from Bra-

zilian Cerrado using SFE and PFE. These studies aim to

demonstrate that technological innovation is able to get


these extracts with efficiency and quality when consider

the maintenance of their activities. Specifically for euca-

lyptus oil, it is noteworthy that Brazil is the world’s largest

exporter. However, the extraction method is rudimentary

and this disqualifies it regarding the decomposition of its

main compound due to high temperatures employed in

the process. The study of the supercritical extraction op-

timization, another work in progress in LTAPPN, allowed

to achieve high yields of essential oil rich in citronellal and

a second product, the oil resin, rich in phenol compounds

with high antioxidant activity. This oil resin is an unknown

product for the producers of eucalyptus essential oil in

Brazil. The high-pressure processes are also being used

in the pretreatment of lignocellulosic waste material to be

employed in enzymatic processes aimed for sugar produc-

tion from sugar cane bagasse for ethanol manufacture or

xylose from coconut fiber. The appeal of this technology

application is linked to supply clean raw materials and

consequently without contaminants that negatively inter-

fere in the enzymatic process. The oil from green coffee

beans is one of the main subjects of study in this labora-

tory. In this research development there is a French insti-

tution collaboration (ICOA, Université d’Orléans). This study

aims to enrich the green coffee oil with its main diterpenes

(cafestol and kahweol) with chemoprotective action. In

this laboratory is also developed research using fish waste

from Brazilian industry, studying conditions for enrichment

of shark liver oil in its main component, the squalene with

several biological activities. The LTAPPN has ten graduate

students with instruction in different knowledge domains,

which makes it possible to perform researches in collab-

oration with other international and Brazilian laboratories

aiming for the application of these extracts for specific

purposes as medicine action. For example, the used of

POSTERS 337

Pitanga seeds extract against leishmaniasis and the study

in vivo of green coffee oil chemoprotective action. The most

recent research line investigated in LTAPPN directs to the

microencapsulation of natural extracts, volatile or not,

using Rapid Expansion of Supercritical Solution (RESS)

system using polymers of low commercial value. Sensory

analysis is also a common subject in this laboratory works

since it is used as a tool for evaluating the aromatic vola-

tile compounds quality in the extraction or encapsulation

process. The LTAPPN aims to contribute in demonstrating

that technological innovation can be feasible if the re-

search results might increase some extracts value by new

extraction methodology or even by the fractionation pos-

sibility and consequent enrichment in active compounds.

Regarding the interaction University/Company, the LTAPPN

has collaboration or/and development with some compa-

nies as Ingredion Brazil, O Boticário and SPF Palatability

Brazil.

SUPERCRITICAL TEChNOLOGy APPLIED TO ThE REUSE OF PASSION FRUIT RESIDUE

339

SUPERCRITICAL TEChNOLOGy APPLIED TO ThE REUSE OF PASSION FRUIT RESIDUE

Daniela Alves de oliveira, sandra R. s. ferreiraFederal University of Santa Catarina (UFSC), EQA/CTC; CP 476 – Trindade, 88040-900, Florianópolis, SC, Brazil;


The passion fruit juice production engenders a large amount

of residues such as seeds and rind. Despite the current

efforts from companies to reuse process residues, large

amounts of passion fruit seeds are still underutilized by

the industries. Part of it has been used to produce seed

oil, due to its high content of unsaturated fatty acids, es-

pecially linoleic acid (up to 70%) finding various applica-

tions in the food, pharmaceutical and cosmetic industries.

Still, in the residue of the cold press oil production — the

seed cake — remains fatty acids, phenolic compounds

and proteins of interest. Phenolic compounds are known

to possess biological activities but due to the molecular

structure and high unsaturation rate of these compounds,

factors like heat and light can cause loss and/or diminu-

tion of their biological properties. The literature reports the

antioxidant and antitumor activities of the passion fruit

seed oil or from specific compounds present in the oil, but

few studies are found concerning the supercritical tech-

nology to obtain passion fruit oil and/or biologically active

derivatives. Thus, the study of methods enabling the ex-

traction of interest compounds from passion fruit seeds

and their stabilization, as precipitation and encapsulation

with polymers, may add value to this residue. The present

study aims: (a) to apply the supercritical fluid extraction


(SFE) on passion fruit seeds and seed cake and compare

it to two different extraction techniques by evaluating their

performances in terms of process yield, total phenolic con-

tent (TPC), antioxidant activity (AA) and composition of

extracts; (b) based on previous results, to select one of the

supercritical extracts to perform phase equilibrium exper-

iments to determine a range of operational conditions to

be employed on precipitation/encapsulation assays. Ex-

traction methods used were: supercritical fluid extraction

(SFE) with CO2 (scCO

2), conducted at 40 °C and 50 °C with

pressures of 150 and 250 bar and 0.5 kgCO2/h; and the

low pressure techniques (LPE) of cold maceration (MAC)

and ultrasonic assisted extraction (UE) using different or-

ganic solvents. The best yield results were obtained by SFE

at 250 bar and 40 °C for the seed (27 ± 1%) and by MAC

with 50% ethanol for cake (6 ± 1%). The cake UE per-

formed with 50% ethanol presented the highest TPC result

determined by the Folin-Ciocalteau method (336 ± 22

mggallic acid equivalents/gextract) and the best AA using

the β-carotene bleaching method (88.8 ± 0% AA after

120 min). The precipitation/encapsulation of bioactive ex-

tracts with poly(lactic-co-glycolic) acid (PLGA) will be done

through the processes of Supercritical Anti-Solvent (SAS)

and Supercritical Fluid Extraction of Emulsions (SFEE)

varying the operational variables and verifying their in-

fluence in the quality of particles produced, seeking the

production of stable micro/nanoparticles. For both precip-

itation/encapsulation methods, a flexible unit that can be

used for SFE, SAS and SFEE is being adapted. The parti-

cles obtained from all conditions will be evaluated by their

size and morphology, using a scanning electronic micros-

copy (SEM), by the interaction between encapsulant and

encapsulated materials through the thermal profiles using

differential scanning calorimetry (DSC), and their crystal-

linity using x-ray diffraction (XRD).

ThE ExTRACTION, MICRONIzATION AND ENCAPSULATION OF CURCUMINOIDS FROM TURMERIC (cúRcuMA LongA L.) USING PRESSURIzED LIqUIDS AND SUPERCRITICAL FLUIDS

341

ThE ExTRACTION, MICRONIzATION AND ENCAPSULATION OF CURCUMINOIDS FROM TURMERIC (cúRcuMA LongA L.) USING PRESSURIzED LIqUIDS AND SUPERCRITICAL FLUIDS

Juan f. osorio Tobón, Mauricio A. Rostagno, M. Angela A. Meireles



The turmeric (Cúrcuma longa L.) plant is widely cultivat-

ed in countries and regions with tropical and subtropical

climates. Turmeric has been used since ancient times as

a condiment, preservative, flavoring, coloring agent and

folk medicine [1]. Turmeric has been investigated for its

biological activity in association with anticancer, antibac-

terial, chemopreventive and chemotherapeutic properties.

Today, turmeric is used mainly as a dye, due to the interest

of replacing synthetic additives with natural compounds

[2]. The yellow color of the rhizomes is due to the presence

of a group of phenolic compounds called curcuminoids.

There are three main curcuminoids, including curcumin (I),

demethoxycurcumin (II) and bisdemethoxycurcumin (III).

Curcuminoids have traditionally been extracted by

liquid-liquid extraction and Soxhlet. Today, the need to

develop more efficient processes and avoid the use of or-

ganic solvents has facilitated the development of more

rapid and environmentally friendly techniques, such as

pressurized liquid extraction (PLE).

PLE is performed under a wide range of conditions

with a compressed liquid. In this region, the liquids are


highly incompressible, and when the solvents are sub-

jected to pressure changes at constant temperature, the

solvent density and solvation power are insignificantly

affected [3]. However, the use of increased temperatures

improves the efficiency of extraction due to the enhanced

rate of mass transfer and diffusion rates [4].

Several techniques are used for the production of

micro-particles, such as spray-drying, spray-cooling and

spray-chilling; however, these methods possess several

disadvantages, such as product degradation, contamina-

tion with organic solvents and the production of large-size

particles [5]. For this reason, supercritical antisolvent pre-

cipitation (SAS) and supercritical fluid extraction of emul-

sions (SFEE) have been proposed as alternatives to the

conventional micronization techniques.

In the SAS process, a liquid solution containing the

solute to be micronized is brought into contact with a su-

percritical fluid (SCF). Therefore, the contact between the

liquid solution and the SCF induces the formation of a

solution, producing the condition of supersaturation and

causing solute precipitation. Several differences exist be-

tween SAS processes and that of SFEE: an emulsion con-

taining the desired substance to be precipitated, which is

dissolved in the SFC, is injected instead of injecting a sim-

ple solution of the substance, causing the formation of a

liquid product.

The objective of this work is to develop a PLE pro-

cess for curcuminoids and to study the micronization and

encapsulation of the extracts obtained by PLE through

supercritical fluids. To meet this objective, the temperature

and pressure effects will be studied relative to the total

yield of curcuminoids in the PLE process. To eliminate the

organic solvent and produce micro- and nanoparticles,

the effects of temperature, pressure and flow on the SAS

POSTERS 343

and the SFEE processes will be evaluated. The curcumi-

noids will be quantified by HPLC. The morphology and

particle size distributions of the micro- and nanoparticles

obtained by SAS and SFEE will be acquired using scan-

ning electron microscopy. Precipitation yield and encap-

sulation efficiency will be determined. The impact of the

different factors on the cost of manufacture will be eval-

uated using SuperPro Designer®.

ACKNOWLEDGEMENTS

Authors are grateful to CNPq (470916/2012-5) for the financial support;

partial support from FAPESP (2012/10685-8) is also acknowledged. Juan

F. Osorio-Tobón thanks CAPES for the PhD assistantship. M. A. A. Meireles


REFERENCES

[1] C. A. C. Araujo, L. L. Leon, Biological activities of Curcuma longa L.,

Memorias Do Instituto Oswaldo Cruz, 96 (2001) 723-728.

[2] P. N. Ravindran, K. N. Babu, K. Sivaraman, Turmeric: The genus Curcuma,

Taylor & Francis, 2007.

[3] C. C. Teo, S. N. Tan, J. W. H. Yong, C. S. Hew, E. S. Ong, Pressurized

hot water extraction (PHWE), J. Chromatography A, 1217 (2010) 2484-

2494.

[4] D. T. Santos, P. C. Veggi, M. A. A. Meireles, Optimization and econom-

ic evaluation of pressurized liquid extraction of phenolic compounds

from jabuticaba skins, J. Food Engineering, 108 (2012) 444-452.

[5] M. J. Cocero, A. Martin, F. Mattea, S. Varona, Encapsulation and co-

precipitation processes with supercritical fluids: Fundamentals and

applications, J. Supercritical Fluids, 47 (2009) 546-555.

MOLECULAR ThERMODyNAMICS ANALySIS OF BIOFUEL SySTEMS

345

MOLECULAR ThERMODyNAMICS ANALySIS OF BIOFUEL SySTEMS

c. g. pereira, n. ferrando, p. Mougin, J. c. hemptinne

DEQ/CT/UFRN – Federal University of Rio Grande do Norte; Av. Sen. Salgado Filho, 3000 Cidade Universitária,

59078-970, Natal, RN, Brazil; E-mail: [email protected]

Thermodynamics has an important role in several indus-

trial sectors, representing the basis in the development of

projects, products as well as in the simulation steps and

process optimization. Thermodynamic equations and mod-

els are used as a tool to support operational decisions.

Over the years, the industry challenge has been to under-

stand the behavior of different systems to improve a pro-

cess or to obtain a particular product. Nonetheless, the

focus changes according to the interests of each area.

Nowadays, the necessity of the environmental preserva-

tion and the requirements from the government, agencies

and society for the use of sustainable products and pro-

cesses has driven the search for new technologies. Since

fuel originating from biomass becomes a real alternative

for petroleum fuel and started to be commercially produced

several studies has been done in order to understand the

systems involved in its processing. Biodiesel is a renewable,

biodegradable and environmentally correct substitute to

mineral diesel, produced through the transesterification

reaction of triglycerides with any short-chain alcohol, such

as methanol or ethanol. The result of this reaction is a mix-

ture of ethyl or methyl esters of fatty acids (biodiesel) and

glycerol. Recent studies have also considered supercritical


or compressed fluids as alternative routes for the separa-

tion and purification steps of biodiesel. When dealing with

separation units the knowledge of the phase equilibria is

essential to evaluate systems in real processing conditions.

In statistical thermodynamics, the properties of a bulk sys-

tem are determined based on the interactions between

the molecules constituting the system. The detailed mo-

lecular interactions (repulsive and attractive) within com-

plex fluids can be evaluated by the three categories of

equations of state (cubic, lattice and perturbation). The

analysis of intermolecular forces present in the system

represents a fundamental role in the understanding and

application of these models. Among the perturbation the-

ories, SAFT (Statistical Associating Fluid Theory) is in-

creasingly used. This EoS explicits in the equation terms

related to the effect of dispersion, chain formation and

association in the molecule. Several variations of SAFT

were derived from the original model [1] (CK-SAFT, PC-

SAFT, SAFT-VR, others). The GC-PPC-SAFT (Group Con-

tribution Polar Perturbed-Chain — SAFT) combines a group

contribution method [2] with the PC-SAFT EOS [3] and an

additional polar contribution. It has demonstrated good

results for different classes of compounds such as esters,

ethers, ketones, alcohols, amines, aromatic/polyaromatic

compounds, and their mixtures. Concerning additional pre-

dictive models, Molecular Simulation has also been suc-

cessful in calculating properties of complex systems. More

specifically, the Monte Carlo simulation technique has been

successfully used to predict phase equilibria of systems

of industrial interest. The present work presents a predictive

analysis of phase equilibrium of systems involved in the

biofuel processing. The experimental data from literature

were compared with predicted values using GC-PPC-SAFT,

PSRK equations of state and molecular simulation. Pre-

POSTERS 347

dictive multiphase equilibria was computed for the sys-

tems: alcohol (ethanol or methanol) + ethyl or methyl esters;

alcohol + glycerol; biofuel blends. The predicted values

showed to be consistent with new experimental data.

REFERENCES

[1] M.S. Wertheim, J. Statistical Physics, 35 (1986) 35.

[2] S. Tamouza, J.P. Passarello, P. Tobaly, J.C. de Hemptinne, Fluid Phase

Equilibria, 222 (2004) 67.

[3] J. Gross, G. Sadowski. Industrial & Engineering Chemistry Research,

40 (2001) 1244.

PILOT PLANT CONCEPT FOR hyDROGEN GENERATION By BIOMASS GASIFICATION IN SUPERCRITICAL wATER INTEGRATED WITh A ThERMOELECTRIC UNIT (h2-BGSCW/TEU)

349

PILOT PLANT CONCEPT FOR hyDROGEN GENERATION By BIOMASS GASIFICATION IN SUPERCRITICAL wATER INTEGRATED WITh A ThERMOELECTRIC UNIT (h2-BGSCW/TEU)

Daltro garcia pinatti, Rosa Ana conteDepartamento de Engenharia de Materiais,

Escola de Engenharia de Lorena, USP;Polo Urbo-Industrial, s/no., Gleba AI-6, Bairro Santa Lucrécia,

12602-810, Lorena, SP, Brazil; E-mails: [email protected]; [email protected]

hydrothermal processing in supercritical water (SCW) has

many advantages over steam [1]: complete sterilization of

pathogens, three regions of hydrothermal process (lique-

faction, catalytic reforming/ gasification, and high tempera-

ture gasification), properties variation of water (density,

solvation power, gas miscibility, and salt crystallization),

biomass drying is unnecessary, high versatility of chemis-

try, enhancement of reaction rates and efficient separation,

and SCW does not have phase transitions. After decades

of development SCW is a great success in coal-fired ther-

moelectric units (TEU) [2] due to the use of ppb-purity

water and Benson boiler. Partial or total replacement of

coal by biomass pellets is under development. SCW ap-

plied to other fields is hindered by a number of problems:

corrosion, incrustation, creep at 25 MPa/700 oC, materials

cost, low concentration of biomass and large water vol-

umes, among others. H2-BGSCW/TEU concept developed

by DEMAR-EEL-USP [3,4] is facing those problems with

the following interdisciplinary approaches: (a) functional

separation of materials (FSM) using high performance con-

crete (HPC, 90 MPa) with addition of rice husk silica to


increase compression resistance, GPa-steel cables to sup-

port tensile strength at room temperature, and castable

refractory for thermal insulation of the pressure vessel; (b)

inside the pressure vessel the reaction tank, heat exchang-

ers and piping are made of thin wall superaustenitic steels,

working at small pressure differences between their walls

at 650 oC; (c) components inside the pressure vessel are

mechanically supported at the bottom at room tempera-

ture and they are free for thermal expansion at the top; (d)

H2-BGSCW reactor is installed between TEU SCW boiler

and turbine; (e) slurry prepared with 5 wt% of clean bio-

mass with addition of activated carbon as catalyst for high

rate H2 production [5]; (f) electric energy hydrostorage (EEHS)

after the first expansion (H2 release) at 12.5 MPa during

19 hours of the day, and expansion in Pelton hydroturbines

at peak hours (3 hours of the day). The last technology

covers the cost of circulation of large volumes of water in

the H2-BGSCW/TEU. The pilot plant concept maximizes

yield of high valued products, minimizes material and cap-

ital investments, utilizes the full capacity of SCW technol-

ogy, and faces up the operational reality of the H2-BGSCW

unit. H2-BGSCW/TEU aims a medium size power plant

(50 MWe, 1300 kg H

2/hr.) to be installed in a distributed way

to incentivize reforestation, nucleation of industrial com-

plexes, generation of employment, revenues and taxes.

REFERENCES

[1] A. A. Peterson et al., Thermochemical biofuel production in hydrother-mal media: A review of sub- and supercritical water technologies, En-ergy Environmental Science, 1 (2008) 32–65.

[2] T. Jäntti, H. Lampenius, M. Ruuskanen, R. Parkkonen, Supercritical OUT CFB Projects-Lagisza 460 MWe and Novercherkasskays 330 MWe, Russia Power Moscow, Russia March 28-30, (2011) TP_CFB_11_04.

[3] D. G. Pinatti, R. A. Conte, Total integration of renewable and fossil energy aiming to a clean and sustainable energy system, J. Energy and Power Engineering, 7 (2013) 58-65.

POSTERS 351

[4] D. G. PINATTI, R. A. CONTE, Scrutiny of available and new technologies

for total integration of renewable and fossil energy for a clean and

sustainable energy system- TIRFE. In: Congress of Bioenergy, April

25-28, 2012, Xi’an, China.

[5] M. J. Antal Jr., S. G. Allen, D. Schulman, X. Xu, Biomass gasification

in supercritical water, Industrial & Engineering Chemistry Research,

39 (2000) 4040-4053.

353


POSTERS 355

MODELING OF SUPERCRITICAL WATER OxIDATION: hyDROThERMAL FLAMES AS hEAT SOURCE

357

MODELING OF SUPERCRITICAL WATER OxIDATION: hyDROThERMAL FLAMES AS hEAT SOURCE

João paulo silva Queiroz, Maria Dolores Bermejo,

Maria José coceroDepartamento de Ingeniería Química y Tecnología de Medio Ambiente,

Universidad de Valladolid; Calle Doctor Mergelina, s/n. 47011, Valladolid, Spain;


Supercritical water oxidation (SCWO) is a useful technolo-

gy for the destruction of waste with residence times lower

than one minute. It takes advantage of the special solva-

tion properties of water above its critical point (374 ºC,

22.1 MPa) to achieve the complete destruction of organic

waste. Oxidation of organics dissolved in supercritical wa-

ter can be carried out in a homogeneous phase due to the

complete miscibility of gases (O2, N

2, CO

2) and organics

with supercritical water. Due to these advantages SCWO

has been also proposed as a technology for replacing com-

bustion in power generation [1,2]. However, some chal-

lenges have still to be overcome for the successful and

profitable commercialization of this technology: corrosion,

salt deposition and high energetic demand [3]. Corrosion

and salt deposition problems, as well as heat recovery

optimization can be avoided by the use of appropriate

materials and reactor designs. The application of reactors

working with a hydrothermal flame as a heat source con-

tributes to overcome many of the challenges present in

supercritical water oxidation technology. Injection of the

reagents over a hydrothermal flame can avoid preheating

problems, such as plugging and corrosion, since the feed


can be injected at lower temperatures (even room tempera-

ture). Also the kinetics is much faster allowing complete

destructions of the pollutants in residence times lower than

1 s. Next to this, the high temperatures associated to the

hydrothermal flames contribute to a better energy recovery

of the reaction heat for shaft work production. For safety

and material limitations the flame has to be properly in-

sulated or kept in distance from the pressure vessel wall.

The configuration of the reactor and fluid injection nozzle

has to be specially projected for this purpose. Computa-

tional fluid dynamics (CFD) is an essential tool for under-

standing the behavior of actual SCWO reactors and for

predicting the efficiency of new designs.

In this work, the SCWO process is studied through

modeling and simulation:

� Methods of estimation for thermal and transport

properties of supercritical water and mixtures are

studied.

� A new global reaction rate for the oxidation of iso-

propyl alcohol in hydrothermal regime is adjusted

from temperature profiles experimental data. This

kinetic model is applied in a parametric analysis of

flame formation, and it is used to analyze the behav-

ior of a supercritical water oxidation vessel reactors.

The kinetic model is able to describe the behavior

of the vessel reactor when working in steady state

hydrothermal flame regime at subcritical injection

temperatures. The model predicts both flameless

and hydrothermal flame regimes.

� The influence of the internal configuration of vessel

reactors for the Supercritical Water Oxidation Pro-

cess is evaluated by simulation and compared to

experimental data. The CFD-model developed pro-

POSTERS 359

vides a good prediction of the experimental results

and can be used for designing reactors working un-

der hydrothermal flame looking at performance and

flame stabilization. Geometrical and operational

parameters are studied.

� Different turbulence-chemistry interaction theories

are tested.

� The energetic possibilities of the process are ana-

lyzed through calculations. Heat integration, gen-

eration of high pressure steam and generation of

electricity by products expansion, are feasible in

SCWO.

REFERENCES

[1] M. Bermejo, M. Cocero, F. Fernandez-Polanco, A process for generat-

ing power from the oxidation of coal in supercritical water, Fuel, 83(2)

(2004) 195-204.

[2] F. Donatini, G. Gigliucci, J. Riccardi, M. Schiavetti, R. Gabbrielli, S.

Briola, Supercritical water oxidation of coal in power plants with low

CO2 emissions, Energy, 34(12) (2009) 2144-2150.

[3] G. Brunner, Near and supercritical water. part II: oxidative processes,

J. Supercritical Fluids, 47(3) (2009) 382-390.

ThE DEVELOPMENT OF INTEGRATED SySTEMS FOR ThE ANALySIS OF BIOACTIVE COMPOUNDS IN NATURAL PRODUCTS EMPLOyING SUPERCRITICAL TEChNOLOGy

361

ThE DEVELOPMENT OF INTEGRATED SySTEMS FOR ThE ANALySIS OF BIOACTIVE COMPOUNDS IN NATURAL PRODUCTS EMPLOyING SUPERCRITICAL TEChNOLOGy

Mauricio A. Rostagno, M. Angela A. MeirelesLASEFI/DEA/FEA (School of Food Engineering),



The increasing evidence that certain compounds present

in natural products may be useful for the prevention and

treatment of important diseases (such as cancer and car-

diovascular diseases) is prompting the development of new

processes for the production of high-added-value extracts

that are rich in these bioactive compounds. This research

line is focused on the investigation of advanced processes

for the production of high-value-added extracts based on

the combination/coupling of modern techniques in all

stages of production, including the pretreatment of the

raw material, extraction, purification, solvent evaporation,

formation of micro/nanoparticles and encapsulation of the

particles formed.

The processes developed make use of ultrasound

and/or microwave in pre-treatment, a combination of su-

percritical fluid extraction (SFE) or pressurized liquids (PLE)

with ultrasound (UASFE and UAPLE) for the extrac tion of

bioactive compounds from the raw material, solid phase

extraction (SPE) and chromatography (HPLC or SFC) for

the purification of crude extracts obtained in the process-

ing line and supercritical antisolvent process (SAS) or su-

percritical fluid extraction from emulsion process (SFEE),

also used in line to eliminate the use of organic solvents


/ the formation of micro/nano particles and encapsula-

tion. The high efficiency of these integrated and combined

systems and the associated processes allows for the ex-

ploration of “green” solvents, such as water, ethanol and

supercritical carbon dioxide, as replacements of the tra-

ditionally used toxic solvents, which include methanol and

petroleum ether. Further, using the systems developed, it

is possible to explore these “green” solvents sequentially

for the selective extraction of different components from

the same raw material.

In the same context, the concept of integrating the

different stages of the process and combining the tech-

niques is applied at an analytical scale. Obtaining infor-

mation regarding the concentrations and profiles of bioactive

compounds in natural products is fundamental and has

many applications, ranging from bioactivity studies of func-

tional food and drugs to the control of the production pro-

cess. In this field, research is focused on the development

of highly efficient and fast analysis systems that encom-

pass these same techniques, consisting of coupling be-

tween the sample preparation (extraction and purification)

and chromatographic analysis steps. Sample preparation

is accomplished through a combination of SFE or PLE us-

ing ultrasound (UASFE and UAPLE) and on-line coupling

with the purification by SPE, which in turn also is coupled

on-line with chromatography analysis (HPLC or SFC). The

design of the integrated system allows different proce-

dures to be performed for the extraction, purification and

analysis steps (UAPLE; UASFE; SPE; SFC) or as a single

on-line process (UAPLE/UASFE -SPE, SPE-SFC; UAPLE /

UASFE-SPE-SFC).

In addition to the priority given to “green” solvents,

another key aspect of this technique is sample output. To

reduce the analysis time, new stationary phases are ex-

POSTERS 363

plored (fused-core particles and monolithic columns) in

conjunction with the use of relatively high column tem-

peratures and flow rates (at the analytical scale). Due to

the high efficiency of these new stationary phases, it is

possible to reduce the column dimensions, thereby reduc-

ing the analysis time and solvent consumption. These ad-

vanced systems are mainly used for the development of

“green” methods for the analysis of a wide variety of bioac-

tive compounds (catechins, flavonoids, isoflavones, alka-

loids, curcuminoids, carotenoids and ecdysteroids), which

is present in different types of samples (tea, coffee, soy-

beans, mushrooms, among other natural products).

Besides focusing on the development of integrated

systems and the methods/processes for the analysis/pro-

duction of bioactive compounds from natural products,

this research also addresses the economic aspects of these

technologies through simulations in which the impacts of

different factors on the cost of production and analysis are

evaluated.

NANOSTRUCTURED COMPOSITES OF SILICA AEROGELS WITh hyDROxy-TERMINATED POLy(DIMEThyLSILOxANE) (PDMS(Oh)) By REACTIVE SUPERCRITICAL DEPOSITION

365

NANOSTRUCTURED COMPOSITES OF SILICA AEROGELS WITh hyDROxy-TERMINATED POLy(DIMEThyLSILOxANE) (PDMS(Oh)) By REACTIVE SUPERCRITICAL DEPOSITION

Deniz sanli, can ErkeyKoc University;

Rumeli Feneri Yolu, Koc University Lojmanlar 17/3, Sariyer, 34450, Istanbul, Turkey;

E-mail: [email protected], [email protected]

Vacuum insulation panels (VIPs) with typical thermal con-

ductivities of 3 to 5 mW/mK are emerging as alternative

systems for effective thermal insulation in buildings and

in household appliances. The achievement of such low

thermal conductivities in VIPs relies on the suppression

of the gaseous conduction by applying vacuum. A VIP is

composed of a core insulation material encased in an en-

velope film. Among different materials, fumed silica and

glass fiber are the most commonly utilized core materials

owing to their appreciably low thermal conductivity val-

ues, especially under vacuum conditions. Current VIPs

are not transparent since neither the core materials nor

the envelopes are transparent. However, transparent VIPs

can be attractive alternatives for insulation of certain parts

of buildings in certain climates. Development of transpar-

ent VIPs requires the development of transparent core ma-

terials and barrier films. Silica aerogels appear as the most

promising nanostructured materials to be implemented

as filler materials in transparent VIPs due to their trans-

parency in addition to their low thermal conductivity. One

drawback of silica aerogels is their poor mechanical prop-

erties and this problem can perhaps be overcome by rein-


forcing aerogels with polymers. In this study, monolithic

composites of silica aerogels with hydroxyl-terminated

poly(dimethylsiloxane) (PDMS(OH)) were developed using

a reactive supercritical deposition technique. The tech-

nique is composed of two stages; the first stage includes

the dissolution of PDMS(OH) in supercritical CO2 that re-

sults in a single phase binary mixture of PDMS(OH)-CO2

and the second stage is the exposure of the silica aerogel

samples to the single phase binary mixture. Initially, the

demixing pressures of PDMS(OH)-CO2 binary mixtures at

various compositions were measured up to 24 MPa to de-

termine the single phase region of the binary mixture. The

demixing pressures were observed to decrease with in-

creasing polymer content of the binary mixture. Subsequent-

ly, deposition experiments were performed with various

PDMS(OH) concentrations and monolithic aerogel compos-

ites were obtained. The polymer uptake of the deposited

aerogels increased with increasing PDMS(OH) concentra-

tion. It was found that the transparency of the aerogels

can be controlled by the amount of the polymer loaded to

the samples. The deposited samples were characterized

by ATR-FTIR and BET analysis. It was revealed that during

the course of the deposition, the polymer molecules react

with the surface –OH groups of the aerogel. The volume

of the polymer in the composites was correlated with the

decrease in the pore volume from the BET results. It was

demonstrated that the deposition resulted in the coating

of silica aerogel surface with a thin layer (~1-2 nm) of

polymer.

ACKNOWLEDGMENTS

We acknowledge the Financial Support of the NANOINSULATE “Devel-

opment of nanotechnology-based High-performance Opaque & Transparent

Insulation Systems for Energy-efficient Buildings Project” being funded

by the EU Program EeB.NMP.2010-1.

ThE DESIGN OF A FUTURE BIOREFINERy BASED ON ThE USE OF SUB/SUPERCRITICAL FLUIDS USING NONTRADITIONAL BIOMASS: BRAzILIAN GINSENG CASE STUDy

367

ThE DESIGN OF A FUTURE BIOREFINERy BASED ON ThE USE OF SUB/SUPERCRITICAL FLUIDS USING NONTRADITIONAL BIOMASS: BRAzILIAN GINSENG CASE STUDy

Diego T. santos, Renata vardanega, M. Angela A. Meireles



Diego T. santos, Juliana Q. Albarelli, Adriano v. Ensinas, françois Maréchal

Industrial Energy Systems Laboratory (LENI), Swiss Federal Institute of Technology Lausanne (EPFL);


The refinery concept applies to the full use of biomass,

employing physical and/or chemical treatments for the

production of several commercial products of higher add-

ed value. The sugarcane industry in Brazil, according to

some experts, is only a pioneer for future “biorefineries”.

The growing number of technologies under development

to produce different products with high added value, such

as plant extracts, ethanol and other chemicals, from bio-

mass represents an important aspect that must be thor-

oughly analyzed, especially from the economic point of

view. The use of environmentally friendly sub/supercritical

fluid technologies to obtain products from biomass has

shown encouraging results. However, studies on the at-

tainment of multiple products in an integrated system,

which combines different and sequential processes with

the use of multiple fluids, are essential for the implemen-

tation of future biorefineries. The main goal of this project

is to use the knowledge and tools available for the energy

integration, life cycle analysis and multi-objective opti-


mization of LENISYSTEM/LENI/EPFL (Switzerland) to

evaluate and optimize the production routes using sub/

supercritical fluids developed experimentally in LASEFI/

DEA/FEA/UNICAMP (Brazil), seeking an integral use of

all parts of Brazilian ginseng (root and aerial parts). There-

fore, it is expected to design a Brazilian ginseng biorefin-

ery based on the use of sub/supercritical fluids. Simulations

of the integrated processes were carried out using the

commercial simulators SuperPro Designer® and Aspen

Plus. Equipment modifications were implemented for the

development of new processes and/or combined process-

es, extending the operational field of LASEFI. Two novel

on-line processes were already developed, including:

a) A process for the pressurized hot organic solvent

extraction of antioxidants from plants as well as

extract precipitation with or without the use of a

carrier material in one-step. This process has been

called OEPO for Organic solvent Extraction and

Particle formation On-line. Using this process, dif-

ferent products (precipitated extract, co-precipitated

extract or encapsulated extract in suspension) with

a very low residual organic solvent concentration

(< 50 ppm) can be obtained directly from plant

materials, employing supercritical CO2 as the anti-

solvent for organic solvent elimination. The OEPO

process consists of hyphenated Pressurized Liquid

Extrac tion (PLE)-Supercritical Anti Solvent (SAS)

precipitation, PLE-SAS co-precipitation and PLE-

Supercritical Fluid Extraction of Emulsions (SFEE).

The OEPO processes were successfully developed

using Brazilian ginseng roots (Pfaffia glomerata) as

a model case.

POSTERS 369

b) A process for the one-step production of emulsions

containing essential oils from saponin-rich pressur-

ized aqueous plant extracts was developed. Named

by our research group as Emulsion from Pressurized

Liquid Extraction (EPLE), the feasibility of this pro-

cess was demonstrated under optimal PLE condi-

tions (12 MPa), including a temperature of 393 K

(120 ºC) and 10 min of static time, using Brazilian

ginseng roots as the source of the saponin-rich ex-

tract, water as the extracting solvent and clove

essential oil as the model dispersed phase.

Therefore, it seems that the best route for the use of

the Brazilian ginseng roots is the co-production of an ex-

tract rich in beta-ecdysone (antioxidant compound), an

extract rich in compounds with surfactant properties and

hydrolysates rich in fermentable sugars. To use the Bra-

zilian Ginseng aerial parts, a similar approach is under

evaluation. After sub/supercritical water hydrolysis of both

raw materials solid residues are formed; accordingly, one

possible conversion process is the evaluation is the pro-

duction of synthetic natural gas (SNG) through supercritical

water gasification. In a broad sense, we also are concerned

with the integration of the proposed Brazilian ginseng

biorefinery to the sugarcane industry.

ACKNOWLEDGMENTS

FAPESP (2010/16485-5; 2012/19304-7; 2012/10685-8) and CNPq.

371

UTILIzATION OF CARBON DIOxIDE IN ThE ALGAL BIOREFINERy

Lindsay soh Department of Chemical and Biomolecular Engineering,

Lafayette College; Easton, PA, USA;

Email: [email protected]

Julie B. ZimmermanDepartment of Chemical and Environmental Engineering,

Yale University;New Haven, CT, USA

School of Forestry and Environmental Studies, Yale University;

New Haven, CT, USA

The imminence of peak oil has implications not only for

the security of our energy future, but also our dependence

on petrochemicals. The use of petroleum as a feedstock

for the production of fuels, plastics, solvents, and other

commodities is rampant and vital in our society. The de-

creasing supply of petroleum requires the need for renew-

able, alternative feedstocks for the production of fuels and

petrochemicals. Due to their fast growth, efficient use of

sunlight, and ability to be grown in varied environments,

microalgae have sparked great interest in terms of their

viability to as a renewable feedstock.

When considering algae as a potential feedstock,

the chemical fractions that are present must be evaluated,

processed, and utilized effectively. In this work, cultivation

of different microalgae species under varied growth con-

ditions was undertaken in order to characterize differenc-

es in biomass, lipid, protein, and starch productivity. The

results were used to inform a combinatorial life cycle as-


sessment, which highlights the need and ability to opti-

mize and tailor algal species and cultivation conditions

for a specific endpoint. Additionally, efficient processing

must be developed in order to harvest, separate, and con-

vert the different chemical fractions efficiently.

Within this context, supercritical carbon dioxide

(scCO2), a green solvent, has great potential towards the

efficient processing of algal biomass as a whole. Not only

is scCO2 considered green compared to other solvents, but

it also has selective and tunable solvent properties and is

easy to separate from end-products. In this work the use

of scCO2 for the efficient extraction and conversion of algal

lipids into biodiesel is explored with further implications

for processing within the context of a biorefinery.

scCO2 was shown to be an effective solvent for the

selective extraction of lipids from algal biomass. The se-

lectivity of scCO2 can be further exploited in order to har-

vest other value-added co-products such as carotenoids

or phospholipids. As a result of the clean extraction pro-

cess, the remaining biomass can be utilized for further

processing to harvest other products such as protein or

starch for a variety of applications such as animal feed,

further fuel production, or even the production of high

value commodities.

While the lipid fraction may have valuable use as

a chemical feedstock, its utilization in the production of

fuels is of great interest to create direct, drop-in replace-

ments for our current requirements. The further use of

dense CO2 as a medium for conversion of lipids into bio-

diesel was also researched. In combination with a het-

erogeneous catalyst, the successful transesterification of

triglycerides into fatty acid methyl esters was shown using

CO2 and methanol. In addition to aiding in the successful

conversion of triglycerides into biodiesel, the process offers

POSTERS 373

benefits in terms of selectivity during conversion. Develop-

ment of downstream technologies and intelligent process-

ing of biomass are necessary to for the viable, economical,

and sustainable use of algae as a renewable feedstock.

EqUILIBRIUM PARTITION OF SOLUTES BETwEEN SUPERCRITICAL CARBON DIOxIDE AND VEGETABLE SUBSTRATES

375

EqUILIBRIUM PARTITION OF SOLUTES BETwEEN SUPERCRITICAL CARBON DIOxIDE AND VEGETABLE SUBSTRATES

freddy A. urrego, José M. del valleFraunhofer Chile Research;

Avenida Mariano Sánchez Fontecilla 310, Piso 14, Las Condes, 7550296, Santiago de Chile, Región Metropolitana, Chile;


The equilibrium partition of an extractable solute between

a solid (vegetable matrix) and a solvent [supercritical CO2

(scCO2)] is one of the limiting factors to the mass transfer

in the extraction with supercritical fluids (EFS). By study-

ing how this process works, one may enhance the preci-

sion and adaptability of mathematical models applied to

the EFS, making them more reliable tools in the simulation

of industrial-scale applications based on laboratory- or

pilot-plant-scale extraction results. We developed two ex-

perimental methodologies to measure the equilibrium par-

tition, and studied different solute-vegetable matrix systems

(oil-prepressed rapeseed, capsanthin-extruded + milled

red pepper, and lycopene-extruded + milled tomato). The

first methodology intersperses equilibration (by continu-

ous recirculation of scCO2 through a cell containing the

vegetable matrix) and extraction steps (mainly a static

methodology), it was applied to all the systems previous-

ly mentioned. The second methodology is based on chro-

matographic principles, where solute diluted in scCO2 is

continuously injected to a column packed with complete-

ly scCO2-extracted substrate, and isotherm/isobar curves

are calculated from dilution profiles read at the exit of the

column with a UV/Vis detector (dynamic methodology), it


was only applied to the lycopene-extruded + milled to-

mato system. The operation conditions were between 40-

67 °C and 22-28 MPa. Different mathematical functions

(Langmuir, Freundlich, Sip’s) were studied, and after mod-

ification and adaptation of the Sip’s isotherm, authors pro-

posed a new isotherm/isobar function. The oil-prepressed

rapeseed system was best-fitted with the del Valle-Urrego

function, whereas the capsanthin-extruded + milled red

pepper, and lycopene-extruded + milled tomato systems

were best-fitted with the Freundlich function. Based on

the results obtained with the mainly static methodology,

its results are considered closer to the physical reality, and

are therefore used as a comparison base. The dynamic

methodology proved to be inadequate to the studied sys-

tem, because lycopene was not so strongly re-adsorbed

onto the vegetable matrix, which led to an isotherm/iso-

bar curve with almost no affinity of lycopene for the solid

substrate. From these studies authors concluded that it is

necessary to measure and model isotherm/isobar curves

in order to improve the precision of mathematical models,

and furthermore, to count on calculated parameters values

that are more related to the physical reality.

ThE INTENSIFICATION OF ThE PROCESS SAPONIN ExTRACTION FROM BRAzILIAN GINSENG (pfAffiA gLoMERATA) USING ULTRASOUND AND hyPhENIzED PROCESSES FOR INTEGRAL PLANT USE

377

ThE INTENSIFICATION OF ThE PROCESS SAPONIN ExTRACTION FROM BRAzILIAN GINSENG (pfAffiA gLoMERATA) USING ULTRASOUND AND hyPhENIzED PROCESSES FOR INTEGRAL PLANT USE

Renata vardanega, Diego T. santos*, M. Angela A. Meireles



*Industrial Energy Systems Laboratory (LENI), Swiss Federal Institute of Technology Lausanne (EPFL);


Until recently, the biorefinery concept has been explored

as a possibility for sustainable processing with the reduced

consumption of energy from fossil fuels. The term biorefin-

ery is applied to the integral use of biomass for the pro-

duction of high-added-value products with minimal residue

generation using sustainable technologies, such as sub-

and supercritical fluids. Sub- and supercritical waters have

several application possibilities, ranging from extraction

to reactions, because they can act as both a benign solvent

and catalyst. Sub- and supercritical waters also can be

used to extract substances that cannot be obtained under

normal temperature and pressure conditions; additional-

ly, these solvents decompose natural biopolymers (cellu-

lose, protein, starch) to produce valuable compounds. To

increase the revenues from a given raw material, coproducts

in the form of valuable phytochemicals can be extracted

prior to performing hydrolysis either at the biorefinery site

or at a site of close proximity. Brazilian ginseng (Pfaffia

glomerata) is a commercialized substitute for ginseng


(Panax) due to its similar morphology and therapeutic ef-

fects. This plant has a large content of saponins, which

can be used as a natural surfactant. Moreover, the residue

from the extraction process is a good source of polysac-

charides. Therefore, this residue can be used to produce

several molecules, among them, second-generation eth-

anol. Considering the potential of this raw material and

the new trends in terms of the development of green tech-

nologies for the production of different products from the

same raw material, the possibility of the integral use of

Brazilian ginseng is very promising. Pressurized fluid tech-

nologies have become very interesting options and are the

focus of this research. First, we intend to develop an in-

tensified method that includes the use of sequential ex-

tractions to obtain distinct products of high-added-value

in each step, namely, extractions of saponins followed by

residue hydrolysis to produce fermentable sugars. After,

using the commercial software SuperPro Designer, the eco-

nomic viability of the process will be evaluated, and the

process will be simulated using ultrasound to increase

the yield of extraction and, thus, the productivity of the

process. Additionally, the possibility of coupling a purifi-

cation process, such as supercritical anti-solvent extrac-

tion, will be evaluated; the aim is to obtain high-quality

extracts using fewer steps than conventional processes.

Some preliminary results have shown that it is possible to

obtain extracts that are rich in bioactive compounds and

that possess emulsification properties from both the roots

and aerial parts of Brazilian ginseng by applying different

processing conditions in terms of the type of solvent used

and the processing temperature. Moreover, we have iden-

tified that it is possible to obtain simple sugars by hydrolyz-

ing the residue from the extraction process of the Brazilian

ginseng roots. Additionally, collaborative works have been

POSTERS 379

developed with colleagues on studies of the hydrolysis of

agricultural and food residues for the production of simple

sugars using sub- and supercritical water assisted by su-

percritical CO2. The hydrolysates obtained can be convert-

ed into second-generation bioethanol by fermentation.

ACKNOWLEDGEMENTS



is also acknowledged. R. Vardanega thanks CNPq (140282/2013-0) for the

Ph.D. assistantship. M. A. A. Meireles thanks CNPq for the productivity

grant (302778/2007-1).

SFE TEChNOLOGy FOR POORLy DEFINED OLIGOMERIC MIxTURES

381

SFE TEChNOLOGy FOR POORLy DEFINED OLIGOMERIC MIxTURES

Julian velez, David f. Esguerra, Mark c. ThiesDepartment of Chemical and Biomolecular Engineering,

Center for Advanced Engineering Fibers and Films, Clemson University;

Clemson, SC 29634, USA; E-mail: [email protected]

Our research is focused on the use of supercritical (SC)

fluids to fractionate and characterize oligomeric carbona-

ceous pitches, potential precursors for advanced carbon

materials. In particular, we are performing semi-continuous

SC extraction experiments, investigating both SC toluene

and SC toluene/N-methyl-2-pyrrolidone (NMP) mixtures

as extractive solvents for fractionating a catalytically pro-

duced pyrene pitch into its constituent oligomers. Although

neat supercritical toluene (Tc = 318.6 °C; Pc = 41.1 bar)

has been shown to be an effective solvent for the recovery

of both monomer and dimer species in high purities, higher-

oligomer solubilities in toluene are notoriously low. The

addition of NMP as a co-solvent enhances oligomeric sol-

ubilities in the extractive, supercritical-solvent phase by

a factor of 3, making possible the recovery of trimer and

higher oligomers. In addition, it also suppresses the un-

desired, AlCl3-aided reactions that occur in the column

between the pyrene oligomers and toluene by forming

Lewis acid-base complexes with the AlCl3 catalyst. A su-

percritical co-solvent mixture consisting of 15 mol % NMP

in supercritical toluene was found to be an effective sol-

vent system for recovering pyrene dimer and trimer cuts

at purities exceeding 99%. These cuts exhibit dramatically


ThE INFLUENCE OF BED GEOMETRy ON ThE KINETICS OF ThE ExTRACTION OF VEGETAL COMPOUNDS WITh SUPERCRITICAL CO2 AND BIOMASS hyDROLySIS

different properties from the starting mixture once they

are isolated: for instance, the trimer fraction is found to

form a liquid-crystalline phase (i.e., mesophase) which is

not observed in either the starting mixture or the dimer

fraction.

A significant advantage of the use of SC extraction

technology in this work is that the high-purity pitch oligo-

mers isolated via SC extraction can serve as excellent

feedstocks for a variety of analytical characterization tech-

niques. For example, molecular-structure information on

the individual species comprising both the starting pitch

and the oligomeric cuts is obtained when these high-pu-

rity fractions are further fractionated by liquid chromatog-

raphy methods (e.g., GPC, HPLC) and/or analyzed with

techniques such as MALDI Mass Spectrometry and UV-Vis

and Fluorescence spectroscopy, etc. By using such a se-

quential separation technique (i.e., SC extraction followed

by analytical separation), the species comprising the pyrene

monomer and dimer fractions have been unambiguously

identified and their concentrations in the starting mate-

rial determined. These results show the potential of SC

fluid extraction technology for the molecular characteri-

zation and quantification of poorly defined, oligomeric and

polymeric mixtures, with applications in both biomass

and heavy fossil fuel conversion.

383

ThE INFLUENCE OF BED GEOMETRy ON ThE KINETICS OF ThE ExTRACTION OF VEGETAL COMPOUNDS WITh SUPERCRITICAL CO2 AND BIOMASS hyDROLySIS

giovani L. Zabot, Moyses n. Moraes, M. Angela A. Meireles



Natural substances extracted from plants present partic-

ular properties that are distinct from the properties of syn-

thetic substances and are useful in the formulation of

bioproducts, as well as in the pharmaceutical field. Novel

extraction techniques, such as the use of supercritical flu-

ids, are acquiring notoriety by providing the selective ex-

traction of bioactive compounds with high quality. In the

field of supercritical technology, investigations are per-

formed to increase the quantitative and qualitative yield

by changing the processing conditions (i.e., pressure, tem-

perature). However, it is necessary to discriminate further

the influence of other variables, such as the bed geometry.

Thus, the aim of this work is to evaluate the use of super-

critical CO2 extraction from the technical and economic

perspectives in obtaining compounds from clove and rose-

mary by using laboratory equipment that possesses 2

one-liter extractors with different height (HB) to bed diam-

eter (DB) ratios. The first and second steps of the thesis

work consisted of the assembly of this SFE-2×1L equip-

ment and in the characterization of the raw materials,

respectively. The third step was the evaluation of the tem-

perature profiles inside the beds, with the goal of selecting

the time for static process and defining the external con-


ditions for the extractor temperatures. The fourth step was

to compare the kinetic parameters obtained by adjusting

the extraction curves for both geometries (E-1: HB/D

B = 7.1;

E-2: HB/D

B = 2.7). Two criteria for scale-up were used. The

first criterion consisted of maintaining equal interstitial

solvent velocities in both geometries, which was not suit-

able for the process. The second consisted of maintaining

constant mass of solvent to mass of feed ratios (S/F) and

extraction times. This criterion was appropriate for this

process due to the similar mass transfer rates used in com-

parison to the commercial Spe-ed equipment (Applied Sep-

arations, 7071, Allentown, USA), which has a 0.1 L extractor

(E-3; HB/D

B = 3.9). Nonetheless, the bed E-2 presented

global yields slightly superior in comparison to E-1, main-

ly due to the excessive compaction observed in E-1. This

behavior was even more pronounced when rosemary was

used. As Laurent et al. [1] reported for the decaffeination

of coffee beans with a particle size of approximately 7 mm,

large HB/D

B ratios (approximately 9) should be used. How-

ever, for smaller particles in the range of 0.4-0.8 mm, which

tend to swell, the HB/D

B ratio should be 3. Using this in-

formation in our study, in which the particle average sizes

were 0.76 mm and 0.66 mm for clove and rosemary, re-

spectively, we conclude that the yield in E-1 (HB/D

B = 7.1)

was influenced by significant compaction and CO2 chan-

neling, which resulted in large axial dispersions of the

solvent-solute. These phenomena were most likely small

in E-2 (HB/D

B = 2.7). The selection of either E-2 or E-1 as

the convenient extractor also depends on studies of the

economic feasibility of the process, because low HB/D

B

ratios influence the construction costs of the extractors.

Thus, in the next step, the cost of manufacturing will be

simulated at different scales and geometries, including a

continuous operation mode. Further, process integration

POSTERS 385

is a recent trend that displays several applications in the

supercritical technology field. In this sense, the biomass

from extraction will be used to hydrolyze the lignocellu-

losic material, with the objective of obtaining high-add-

ed-value substances.

ACKNOWLEDGEMENTS



is also acknowledged. G. L. Zabot thanks FAPESP (2011/23665-2) and M.

N. Moraes thanks CAPES for the Ph.D. assistantships. M. A. A. Meireles


REFERENCES

[1] A. Laurent, E. Lack, T. Gamse, R. Marr, Separation operations and

equipment, in: A.V.G. Bertucco (Ed.) High pressure process technolo-

gy: fundamentals and applications, Elsevier, Amsterdam; New York,

2001, pp. 351-403.

387

INDEx

Albarelli, Juliana Q. 237, 367Albuquerque, Carolina L. C. 245Albuquerque, Flávio C. 195, 261Alcázar-Alay, Sylvia C. 249Anderson, Mark 89Andreatta, Alfonsina E. 251, 327Araújo, M. E. 317Azevedo, Evelin C. 257Azevedo, F. F. M. 317

Balboa, Elena M. 253Baskette, Rudy 275Batista, C. F. M. 317Bazito, Reinaldo 179Benelli, Patícia 257Benezet, Jean-Charles 147Bermejo, Maria Dolores 357Berni, Mauro 297Bisaia, Rodrigo 261Bochon, I. 189Bolaños, Gustavo 79Borges, Endler Marcel 261Braga, Mara E. M. 265, 293Brennecke, Joan F. 269Bruinhorst, Adriaan van den 71Brunner, Gerd 21

Cabral, Marcos Vinícius Riscado 195Cabrera, Ingrid 61Canales, Roberto 269Cardenas-Toro, Fiorela P. 273Carneiro, Cristiana B. 297Carpanedo, Thayane 275Carvalho, Pedro Ivo N. de 277Chan, Yi Herng 177Chiavone-Filho, Osvaldo 281Ciftci, Ozan Nazim 217, 285Cocero, Maria José 45, 117, 357Comim, Sibele R. Rosso 257, 287Conte, Rosa Ana 349Corazza, Marcos L. 125Córdoba, Alba 61Cotabarren, N. 121Crone, M. 131Cunha, M. A. E. 317

Dahmen, Nicolaus 107

Debien, Isabel C. N. 289Devor, Robert 303Dias, Ana M. A. 265, 293Domínguez, Herminia 253

Elizondo, Elisa 61Ensinas, Adriano V. 237, 367Erkey, Can 53, 365Escorsin, Alexis M. 125Esguerra, David F. 221, 381

Fages, Jacques 147Farías-Campomanes, Angela M. 253Farouk, Bakhtier 213Ferrando, N. 345Ferreira, Sandra Regina Salvador 65,

257, 287, 325, 339Ferrer, Lidia 61Fornari, Tiziana 229Forster-Carneiro, Tania 233, 249, 273, 297Francisco, María 71Frerich, Sulamith 239

Ge, Zhiwei 305Gomes, M. Thereza M. S. 301Gomez, Cesar 327Goto, Motonobu 95Grandelli, Heather E. 303Guo, Liejin 203, 305Guo, Simao 305

Hammond, Peter J. 321Hasan, Nusair 213Hegel, P. 121Hemptinne, J. C. 345Hijazi, Nibal 147Hintze, Paul E. 303Hodes, Marc 135Hrnčič, M. Knez 113Huddle, Thomas 209

Iannace, S. 139Ibáñez, E. 169

James, Kenneth J. 275Jesus, Susana P. 307Jin, Hui 305, 311Jr., Richard L. Smith 35Jr., Valdir F. Veiga 253


Kanda, Hideki 95King, Jerry W. 29Kiran, Erdogan 155Kitchens, Christopher L. 165Knez, Ž. 113Kroon, Maaike C. 71Kruse, Andrea 41

Lu, Youjun 305, 313

Machado, N. T. 317Maio, E. Di 139Maloney, Phillip 303Maréchal, François 237, 367Markočič, E. 113Marosi, Gyorgy 147Marques, Fabricio C. 321Martínez, Julian 225Martini, Raquel E. 251Marulanda, Victor Fernando 323Meireles, M. Angela A. 195, 233, 237,

245, 249, 253, 261, 273, 277, 289, 297, 301, 307, 331, 341, 361, 367, 377, 383

Meredith, Carson 151Mezzomo, Natália 287, 325Mićić, Vladan 177Milanesio, Juan M. 251, 327Minnick, David L. 329Moigne, Nicolas Le 147Moraes, Moyses N. 331, 383Moreno, Evelyn 61Mougin, P. 345Müller, S. 131Muntó, María 61

Nagy, Zsombor 147Ndiaye, Papa M. 125Netti, P. A. 139Núñez, Gonzalo A. 333

Oliveira, Alessandra L. 335Oliveira, Daniela Alves de 339Oliveira, José Vladimir de 207, 287Omar, Wissam 111Orsi, S. 139Osman, Noridah 111

Pedrosa, Rozangela C. 257Pereda, S. 121Pereira, Carlos V. Lamarão 253Pereira, C. G. 345Pessoa, Fernando Luiz Pellegrini 281Petermann, Marcus 189, 239Peters, Cor J. 71Pinatti, Daltro Garcia 349Pioro, Igor 85Prado, Juliana M. 233, 297Proença, Thaís A. 287

Queiroz, Eduardo Mach 281

Queiroz, João Paulo Silva 357Quinzani, Lidia 327Quispe-Condori, Socrates 173

Rajab, Ahmad 111Ravber, M. 113Rocha, Sandro R. P. da 143Rodier, Elisabeth 147Rojas, Paula 61Romão, Guilherme 261Rostagno, Mauricio A. 261, 277, 341, 361Rowson, Neil 321

Sala, Santi 61Saldaña, Marleny D. A. 183Sanli, Deniz 365Santana, A. L. 317Santos, Diego T. 301, 367, 377Santos, Regina C. D. 127, 321Sauceau, Martial 147Scofield, Arthur de Lemos 195Scott, Adam 221Scurto, Aaron M. 77, 329Škerget, M. 113Smirnova, Irina 51Soh, Lindsay 371Sousa, Hermínio C. de 265, 293Spilsbury, Christopher G. 193Striumia, Miriam 327Subramaniam, Bala 57Sunol, Aydin K. 199Surma, Jan 303

Takahashi, Shinya 155Teja, Amyn S. 161Temelli, Feral 217, 285Thies, Mark C. 221, 381Timko, Michael T. 105Tobón, Juan F. Osorio 341Türk, M. 131

Uemura, Yoshimitsu 111Urrego, Freddy A. 375

Valle, José M. del 93, 333, 375Vardanega, Renata 367, 377Vazquez, M. F. Barrera 251Veciana, Jaume 61Vega, Lourdes F. 25Velez, Julian 221, 381Ventosa, Nora 61Vigh, Tamás 147

Weidner, Eckhard 99Wei, Liping 313

Yusup, Suzana 111, 177

Zabot, Giovani L. 331, 383Zheng, Pengfei 313Zimmerman, Julie B. 371Zubeir, Lawien F. 71