Industrial Production of Microalgae

Industrial production of microalgae biomass with flat-panel airlift

photobioreactors

11

photobioreactors

ALGAE 2009, Hamburg

1

Dr. Peter Ripplinger,Subitec GmbH, Stuttgart

1. Subitec GmbH: our company profile

2. Basics of microalgae cultivation

3. Our product: the Flat-Panel Airlift (FPA) Photobioreactor

4. Pilot plants

22

4. Pilot plants

5. The current situation and future perspectives

2

Microalgal biotechnology


Vision

„Subitec is revolutionising the use of algae biomass:

On the basis of the globally patented flat-panel airlift On the basis of the globally patented flat-panel airlift photobioreactors, designable algae biomass can for the first

time be produced on an industrial scale with a low consumption of resources.”


Company profile

• Spin-off of the Fraunhofer Institute for Interfacial Engineering

and Biotechnology (IGB) in Stuttgart

• Two patent families regarding the Flat Panel Airlift-

Photobioreactors granted worldwide

• Pilot plants with E.ON Hanse AG (in Hamburg) and EnBW AG

(near Stuttgart) since 2008

• Numbers of employees: 6


Products and Services

• Systems for the cultivation of microalgae based on

5 L, 30 L und 180 L-FPA photobioreactors

• R&D partner for biorefinery concepts based on algae biomass

6

on algae biomass

• Production of algae biomass for the cosmeticand pharma industry and for product development

• Development of cultivation processes for theproduction of lipid-rich algae


flasks 10L bottlesAgar culture FPA photobioreactors

Process development for new algae strains

777

50 mL 200 mL 500 mL

0 1 4 6 10 14 16 18

5L 30L 180L

[ time in weeks]


Customers´ needs

BioenergyFeed &

Food

Infinita Renovables SA

Algafluid SA

Cognis AG

Soliance / KD-Pharma

Roquette

Carroux Innovation


CO2 Fixation

Food

E.ON AGEnBW AG

RWE Power AG

Solvay

Carroux Innovation

Scretting, BioMar

Vattenfall Europe AG

FairEnergie GmbH

Prices and market volume of algae products

Pharmaceuticals / Cosmetics

Fine chemicals / Food

Price

100 €/kg

99

Protein (Feed)

Biomass

Energy

Market volume

9

10 €/kg

1 €/kg


Algae production

• Photobioreactordevelopment

• Process optimisation

Processing

• Harvesting/Separation• Pulping• Extraction

Products

• Pharmaceuticals• Cosmetics• Dietary supplements

Positioning along the value chain

10

• Process optimisation• Engineering of

production facilities

Subiteccore competence

Subitec together with industrial partners Markets

• Extraction• Product formulation

• Dietary supplements• Feed• Energy


Pilot Plant Stuttgart-Vaihingen

111111

Pilot plant of the Subitec GmbH in Stuttgart-Vaihingen (2005)





4. Pilot plants

1212

4. Pilot plants


12

Why Microalgae?

+ Productivity per ha is 5 to 10-fold higher than

for crops or other plants

+ „designable“ biomass

+ Usage of CO2 from combustion processes

+

1313

+ Microalgae biomass is free of lignocellulose

+ No competition with the production of food;

no use of arable land for the microalgae cultivation

+ Net energy production is possible

- High capital costs


growing culture(optimal N/P-supply)

Valuable Substances

Proteins

Carbohydrates

LipidsPigments

Carbohydrates as energy storage

„designable“ algae-biomass

1414

Valuable Substances

ProteinsCarbohydrate

s

LipidsPigments

Carbohydrates

ValuableSubstances

Proteins

Carbohydrates

Lipids

Pigments

Lipids as energy storage


Comparison of different culture systems

Open ponds Tubularsystems

Flat-PanelAirlift (FPA)Reactor

high low low

Volumetric low medium/high high

Risk of contamination

1515

Volumetricproductivity

low medium/high high

Cell density very low medium/high high

Energy input per volume

low high low

Capital costs low high medium


Is net energy production achievable?

Energy content of algae biomass

- energy input for cultivation

1616

- energy input for cultivation

_________________________

Net energy production ???


Comparison of the energy input per kg DW of different production systems

100

120

140

160

1717

0

20

40

60

80Energy input

(MJ/kg ODW)

Raceway tubular PBRs FPA reactorspond

Energy content of algae biomass





4. Pilot plants

1818

4. Pilot plants


18

Light supply in dense algae cultures

Problems:

• Inhibition of photosythesis

• Optimal light intensity is 5 to 10-

fold lower than the natural light

intensity

• Limitation due to dense cultures

Limitation0 µE m-2 s-1

Inhibition

2000 µE m-2 s-1

Optimum400 µE m-2 s-1

1919

• Limitation due to dense cultures

Solution:

• Continous transportation of the

algal cells through the different

zones

• Use of the „flashing light effect“

Light

0 µE m s

Cross section of the reactor

Process engineering

� efficient light supply to all cells

� complete homogenious intermixing

� low mechanical stress to the cells

� simple temperature and pH control

� efficient gas exchange

Halfshells of the FPA madefrom deep-drawn plastic sheets

FPA technology

202020

� efficient gas exchange

Cost-effectiveness

� high volumetric productivity

� high cell densities

� high reactor volumes

� low capital and operating costs

� high reliabilitystatic mixers

flow


FPA-Reactor, 3rd Generation (2008)

2121

Technical data: Heights 270 cm Volume 180 lLengths 175 cm Material PVC or Thickness 5 cm PETg





4. Pilot plants

2222

4. Pilot plants


22

Pilot Plant Eutingen-Weitingen

232323

Pilot plant of the Subitec GmbH in Eutingen-Weitingen (2008)

4. Pilot plants

Pilot plant Eutingen-Weitingen

Owner and operator

Subitec GmbH

Project partnerEnBW AG

SiteSiteHof Weitenau;Biogas plant in Eutingen-Weitingen

Plant descriptionCulturing system for microalgae on the basis of

180 Liter Flat-Panel-Airlift Photobioreactors

Total volume: 4.13 m³(3 modules with 8 reactors each)

Start of operation

2008

4. Pilot plants

Flow chart – production module

25254. Pilot plants

Layout of the pilot plant in Eutingen-Weitingen

264. Pilot plants

Pilot plant in Hamburg-Reitbrook

CustomerE.ON Hanse AG

SiteErdgasspeicher Hamburg-Reitbrook



274. Pilot plants


Total volume: 1,44 m³(2 modules with 4 reactors each)

Scope of services• Planning, construction and technical assistence

for the operation of a cultivation system for microalgae

• Use of flue gas from a CHP

Start of operationMay 2008

Pilot plant in Reutlingen

CustomerFairEnergie GmbH

SiteStadtwerke Reutlingen



28


Total volume: 4.32 m³(4 modules with 6 reactors each in a greenhouse)

Scope of services• Planning, construction and technical assistence

for the operation of a cultivation system for microalgae

• Use of flue gas from a CHP

Start of operationMarch 2010

4. Pilot plants

Pilot plant in Spain (180 m³, basic engineering)

29294. Pilot plants

1. A short history of Subitec GmbH



4. Pilot plants

3030

4. Pilot plants


30

Microalgae cultivated in the FPA reactor

Lab scale

Marine algaemax. DW

(g/l)Ø Prod. (g

DW/l*d)

Isochrysis spec. (clone T.iso) 10 0,5

Nannochloropsis oculata 13 1

Tetraselmis suecica 16 0,6

Platymonas subcordiformis 12 0,5

Other algae (sweet water)

Chlorella vulgaris 12 0,8

Chlorella sorokiniana 12 1,3

Eigenisolat DSN 5.1 16 0,7

Haematococcus pluvialis 2,5a 0,5

5b 0,3

Phaeodactylum tricornutum 25d 1,5

12e 0,9


Growth Curve Phaeodactylum tric. in autumn 2007

7

8

9

10

dry

weig

ht

[g D

W/l

]

2,00

2,50

vol. p

rodu

ctiv

ity [g D

W/l

*d]

Growth curve of an outdoor cultivation (30 L FPA reactor)

inoculation production phase

32

0

1

2

3

4

5

6

1.9.07 8.9.07 15.9.07 22.9.07 29.9.07 6.10.07 13.10.07 20.10.07

Date

dry

weig

ht

[g D

W/l

]

0,00

0,50

1,00

1,50

vol. p

rodu

ctiv

ity [g D

W/l

*d]

Dry weight Outdoor cultivation Productivity


Annual productivity in different climate zones

Location

Productive

days per

year

with ø 1g

ODW/l*d

with ø 0,8 g

ODW/l*d

Productivity per ha and year

(t ODW / ha*a)

3333

yearODW/l*d ODW/l*d

tropical 365 137 110

Mediterranean region 300 113 90

central European 240 90 72

Stuttgart 200 75 60

Estimated for 180 L type of FPA reactor with a 2.5 m distance between rows

Productivity > 100 t ODW / ha


Production costs and capital costs

For a 1 ha plant:

� capital costs 1,500,000 € (25% for FPA photobioreactors)� productivity 120 t / ha x year

� production costs:

3434

Depreciation 2,000 € / t ODWElectricity 200 € / t ODWNutrients 1,500 € / t ODWPersonnel costs 500 € / t ODWTotal (incl. dep.) 4,200 € / t ODW

For a 100 ha plant: ????


Future tasks – work in progress…

• Temperature control

• Lowering the energy input for the cultivation process

• Process automation• Process automation

• Optimisation of the FPA photobioreactors

• Cost reduction of the culture media


Temperature control for outdoor cultivation

• Cultivation of temperature-tolerant algae strains:

Haematococcus pluvialis 20°C

Phaeodactylum tricornutum 22°C

Chlorella vulgaris 25°C

• Development of new and more effective cooling systems

• Adaptation of greenhouse technology for algae Chlorella vulgaris 25°C

Chlorella sorokinana 37°C (43°C)

Dunaliella salina 35°C

Scenedesmus obliquus (10°C) 31°C (36°C)

Spirulina platensis (18°C) 36°C (40°C)

From: Cyrille Gattiker, Masterthesis, Lausanne EPFL 2009

technology for algae cultivation


Pressure losses for the FPA system

Total working pressure = sum of partial pressure losses

Compressor TubingSterile filtration

Membrane Water pressureExhaust

gas

< 50 mbar ca. 150 mbar 250 mbar 262 mbar 100 mbar

37

< 50 mbar ca. 150 mbar 250 mbar 262 mbar 100 mbar

Possible optimisation:

1. Membrane2. robust algae cultures / mixed cultures3. Use of industrial processes which deliver CO2 under pressure4. Airflow adapted to light intensity/actual productivity

Energy Input: 100 – 200 W / m³


Valuable substances

Residues (>90% of biomass)

Filtrate

Algae biomass Extraction

Heat District heat

Integrated production processfor microalgae biomass

3838

anaero

bic

dig

estion

AmmoniumPhosphateConcentrate

Filtrate

Flue gas

Stripping / Precipitation

Biogas plant 500 kWel

Heat

Greenhouse


Network partners

39

Bundesland Baden-Württemberg

Thank you very much for your attention!

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Documents

Industrial Production of Microalgae