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DEPARTMENT OF ENGINEERING SCIENCE

May 19, 2015

The biorefinery sustainability puzzle –

A systems engineering view

by Dr Elias Martinez Hernandez Department of Engineering Science University of Oxford

Outline

June 16, 2015

Page 2

1. Context

2. Fossil resource-based economy vs bio-economy

3. Biorefineries and Sustainability

4. The Biorefinery Sustainability puzzle

5. Systems engineering framework

6. Case studies

7. Conclusion

2

Context

June 16, 2015

Page 3

Human population

>9 billion (2050)

Urbanisation

70% (2050)

Food demand

>40 Petacal/d (2050)

Total water demand

5500 billion m3 (2050)

Energy demand

>17 Mtoe (2035)

Source: Beddington, 2009

VS

Resource depletion

Increased waste generation

Climate change

Biodiversity loss

Ecosystem deterioration

Demands increasing fast but limited and reduced capacity to provide primary

resources = unbalanced system

Predominant production-consumption system

Fossil resource-based economy vs bio-economy

June 16, 2015

Page 4

Fossil resource-based economy Large scale and centralised linear systems

decoupled from the ecosystems, which provide us with supporting resources, has resulted in unsustainable

economic development

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Fossil resource-based economy vs bio-economy

June 16, 2015

Page 5

In the bio-economy biorefineries have the potential to emerge as circular systems, closing resource loops to maintain the ecosystem capacities and support local development

Bio-economy Uses biomass as a potential

renewable resource Enables carbon and nutrient

cycling Enables integration with other

alternative sources at local scale Potential for community integration

Biorefineries and sustainability

June 16, 2015

Page 6

Biorefinery definitions

Biorefineries are industrial facilities for the “sustainable processing of biomass into a spectrum of bio-based products (food, feed, chemicals, materials) and bioenergy (biofuels, power and/or heat)”. IEA Bioenergy Task 42 on Biorefineries

A biorefinery is a facility that integrates biomass conversion

processes and equipment to produce fuels, power, heat, and value-added chemicals from biomass. The biorefinery concept is analogous to today's petroleum refinery, which produce multiple fuels and products from petroleum. NREL

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Biorefineries and sustainability

June 16, 2015

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Advanced biorefineries will become complex interacting systems with desired emerging properties of integration, process flexibility, multiple outputs and ultimately the property of SUSTAINABILITY. This requires a holistic approach for their design and implementation

Biorefineries and sustainability

June 16, 2015

Page 8

Sustainability definitions

From the concept of sustainable development as the capacity to meet “the needs of the present without compromising the ability of future generations to meet their own needs” Brundtland

Commission report

“The art of living well within ecological limits” Prof Tim Jackson,

University of Surrey

Sustainability is a dynamic concept and implies that to be able to maintain the level of well-being of a society in the long term, the

constraints set by ecosystems must be observed.

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SOCIETY ECOSYSTEM

The Biorefinery Sustainability Puzzle

June 16, 2015

Page 9

Primary

resource

•Biomass

•Minerals

•Nutrients

•Soil/Land

•Fossil fuel

•Water bodies

•Air/wind

•Solar irradiation

•Biodiversity

•Etc.

Population

needs

•Nutrition

•Sanitation

•Water

•Thermal

comfort

•Mobility

•Housing

•Recreation

•Income

BIOREFINERY

BIOMASS

PRODUCTION

•Food crops

•Energy crops

•Crop residues

•Forest residues

•Aquaculture

•Livestock

Process A

Process

unit

Process B Process C

Process D

ECONOMY

•Commodity

•Specialty

•End product

•Utility

•Employment

POLICY

•Emission

regulation

•Reduction

targets

•Incentives

•Standards

OTHER VALUE CHAINS

•Food/feed

•Renewable energy

•Natural polymers

•Petrochemicals

•Fuels/utilities

•Construction materials, etc.

The Biorefinery Sustainability Puzzle

June 16, 2015

Page 10

POLICY

•Renewable energy targets

•GHG reduction targets,

carbon credits

•Standards for labelling

‘green’, ‘renewable’ or

‘sustainable’ products

•Subsidies, tax incentives

BIOMASS PRODUCTION

Biomass Availability

•Yields and land use

•Field emissions

•Nutrient management

•Biomass quality

•Water, fossil energy and other

resources use

Biomass economy

• Logistics (collection and

transportation costs)

• Job creation

• Production costs

• Current biomass uses

MARKET

•Product demand

•Commodity vs. specialty

•Product prices

•Trade of carbon credits

•Price of competing products

and fossil resources

ECOSYSTEMS

•Impacts on ecosystem dynamics and

services (nutrient cycling, CO2 capture,

etc.)

•Biodiversity

SOCIETY

•Food vs. fuel debate

•Public health and safety

•Public acceptance

•Employment and development

•Changes in consumer behaviour

BIOREFINERY

•Feedstocks

•Processes

•Products

•Product standard specifications

•Technology development status

•Direct process emissions

•Process design and integration

•Process control and flexibility

•Process intensification

•Plant capacity and location

•Biorefinery optimisation

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Systems engineering framework

June 16, 2015

Page 11

Intra-process

Society

Inter-process

Value chains

Ecosystems

A key is how to integrate the pieces of the puzzle to achieve a particular long term sustainability objective under a particular

context/scenario.

Systems engineering framework

June 16, 2015

Page 12

Case studies

Development and

application of tools

(process integration and

simulation, LCA, system

dynamics, economic

analysis, etc.)

Conceptual

Applied to

Feedback Feedback

Results

Mathematical

(modelling)

Applied to

Supports

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Case studies – Interprocess integration

June 16, 2015

Page 13

Bioethanol and AX extraction processes Wheat

Milling

Hydrolysis

Fermentation

Centrifugation

Drying

DDGSBioethanol

Washing

Treatment 1(TMU-1)

Sieving and washing 1 (SWU-1)

TMU-2 & SWU2

Treatment 3

AX precipitation (PPU-1)

Centrifugation (CFG-2)

Ethanol washing (WSU-2)

Ethanol recovery and purification

1

2

3

4

5

6

79

Drying (RDY-2)

AX

10

grain

SW3 & UF

811

12

bran

Case studies – Interprocess integration

June 16, 2015

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Bioethanol and AX extraction processes

Avoided loss in

bioethanol sales

Additional

capital cost

Net profit

increase

(M£/a) (M£/a) (M£/a)

22.83 0.11 22.72

After integration of the co-product process

interactions using mass pinch analysis1

Martinez-Hernandez et al. 2013. Applied Energy 104, 517−526

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Case studies – Intraprocess and value chain integration

June 16, 2015

Page 15

Whole Jatropha fruit utilisation

Process Energy

recovery (%)

GHG

emissions (t

CO2-eq/t fruit)

Oil to biodiesel 39-41 0.63

Whole Jatropha

fruit utilisation 53-57 -0.07

After integration of the co-product process interactions using

energy pinch analysis and carbon footprint

analysis 393 kt fruit/y

Martinez-Hernandez et al. 2014. Biomass Conversion and Biorefinery

2014; 4(2):105-124

Seed

processing

Biodiesel production

Anaerobic digestion

and Biogas-to-

power

Green diesel

production

IBGCC-H2

Seeds

271.2

Biodiesel

100

39.6

Green diesel

93.4

Waste water

2.4

Waste

5.3

Cake

75.1

Methanol

11.5

H2

2.85

Steam

2.9

Optional uses

Utility integration

Oil

104.7

Jatropha cultivation

IBGCC-CH3OH

CO2

11.2

Flue gas 496.4

Flue gas 461.6

1

2

4

3

5

2

4

3

Glycerol

10.7

19.0

4

1 2 3

Ash 3.2

Purge 1.1

Acid gas

42.1

Acid gas

70.1 Ash 3.2

Purge 6.7

Shells

m: 122.1

5

5

Net power

0.28

Net power 0.23

Heat 0.01

Power 0.15

Heat 0.02

Power 0.026

Sludge

Husk

91.4

19.9

For animal

feed

As fuel

As fuel

As fertilizer

Net power

As fuel

Propane fuel mix

3.4

Biogas leakage

(2%) Flue

gas

Heat 0.4

Power 0.06

m: Mass flow rate in Gg/y

Heat and power in PJ/y

IBGCC: Integrated Biomass Gasification and

Combined Cycle

BD: biodiesel; GD: green diesel

BD GD

4 1.1 1.0

5 0.81 0.76

Case studies – Environmental, economic and policy

June 16, 2015

Page 16

Marginal analysis of economic and EI saving potentials

F

Cf

If

P

Vp

Dp

A

Ca

Ia

U

Cu

Iu

M

Cm

Im

BIOREFINERY

Feedstock(s)

Product(s)

Aux. raw

materials

Utilities

Emissions /

wastes

REFERENCE

SYSTEM

(Based on

fossil

resources)

Equivalent

product(s)

P×β

Ipeq

End

use

Iend

Tp

BIOMASS

PRODUCTION

(G)

Energy and

material resources

Emissions

CO2

(B)

Tf

If = G+Tf−B

CVP

VOPV

ICP

COPCValue On Processing

EI credit on Processing

Cost of Production

EI of Production

For a stream: V−C = Δ (margin) =

i

e Economic margin

EI savings margin

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Case studies – Environmental, economic and policy

June 16, 2015

Page 17

Bioethanol

case study

Martinez-Hernandez et al. 2013. Chem Eng Res Des104, 517−526

Software tool available at biorefinerydesign.webs.com/Biorefsys

-0.8

-0.6

-0.4

-0.2

0.0

0.2

0.4

0.6

0.8

0 2000 4000 6000 8000 10000 12000 14000 16000 18000

EI va

lue

as

CO

2-e

q (t

/ t)

Mass flow rate (x103 t / y)

Streams EI profile

CVPICP

f1WHEAT

f1-2MILLED WHEAT

f1-2-3: SLURRY f1-2-3-4: SUGARS

f1-2-3-4-5FERMPROD

f1-2-3-4-5-6BEER2

p1: ETHANOL

f1-2-3-4-5-7WET SOLIDS

p2: DDGS

Biorefinery EI savings = 426.8 kt CO2-eq/y

0

100

200

300

400

500

600

700

0 2000 4000 6000 8000 10000 12000 14000 16000 18000

Ec

on

om

ic v

alu

e (£

/ t

)

Mass flow rate (x103 t / y)

Streams economic profile

VOP

COP

f1WHEAT

f1-2MILLED WHEAT

f1-2-3: SLURRY f1-2-3-4: SUGARS

f-1-2-3-4-5FERMPROD

f1-2-3-4-5-6BEER2

ETHANOL

f1-2-3-4-5-7WET SOLIDS

DDGS

Biorefinery economic margin = 117.7 M£/y

Case study – Local integration with ecosystems

June 16, 2015

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Biorefining

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Case study – Local integration with ecosystems

June 16, 2015

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Identify ecosystem and

man-made components

Identify states in each

component according to

the resources of interest

Identify and characterise

processes and flows

affecting a particular state

Identify interactions that

have an impact on the

system performance

Is other state

involved?

Yes

No

Collect data, select

models and

calculate

Characterisation of techno-ecological

integration for analysing the effect on

ecosystem dynamics and services

Case study – Local integration with ecosystems

June 16, 2015

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Local area: Whitehill and Bordon, UK

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Case study – Local integration with ecosystems

June 16, 2015

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Assess potential for biomass supply (as ecosystem service) from heathland areas (1600 ha) while observing the constraints given by the ecosystem dynamics under various scenarios of biomass cutting and nitrogen recycling

Assess system performance in terms of level of satisfaction of

heat and electricity demands

Case study – Energy production from heathland

biomass

June 16, 2015

Page 22

HEATHLAND

AIR

N in

soil

Biomass

N deposition

Total N available

for growth

Mortality

Mineralisation

N in

litter

Immobile

N

Mineral

N

N surplus

N

uptake

Biomass

growth

Biomass

harvesting

N

recycle

ENERGY PRODUCTION

Process

Component

State

Flow

CO2

C in

soil C in litter C loss

Heat

Soft

biomass

Electricity

Anaerobic

digestion

Combined heat

and power Woody

biomass

Biogas

Digestate

To another

system

C and N emissions

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Case study – Local integration with ecosystems

June 16, 2015

Page 23

Martinez-Hernandez et al. 2015. Env Sci Tech DOI: 10.1021/es505702j

Case study – Local integration with ecosystems

June 16, 2015

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Annual cutting ratio = 0.2 Annual cutting ratio = 0.4

Ecosystem dynamics

No N recycle

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Case study – Local integration with ecosystems

June 16, 2015

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Steady state performance

Case study – Local integration with ecosystems

June 16, 2015

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filled markers: No N recycle

open markers: with 50% of N recycle

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Case study – Local integration with ecosystems

June 16, 2015

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Cumulative biomass harvest and nitrogen stored in soil after 50 years of

heathland management

Case study – Local integration with ecosystems

June 16, 2015

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Local needs

- Population:17000

- Electricity (total): 9.11 GJ/y/person

- Heat (total): 40.3 GJ/y/person

Heathland area: 1600 ha

Nitrogen

recycle

fcut for

best

trade-

off

Electricity

production at

SS

(GJ y−1)

Heat

production at

SS (GJ y−1)

% of the local

electricity

demand

supplied

from

heathland at

SS

% of the

local heat

demand

supplied

from

heathland

at SS

C captured +

avoided C

emissions

after 50 years

(t ha−1)

Nitrogen

deposition

limit

(kg ha−1 y−1)

0 0.4 36860 46350 17.0 4.8 120 35

10% 0.4 38250 48100 17.6 5.0 125 35

50% 0.4 42700 53700 19.7 5.6 140 30

95% 0.5 53900 67800 24.8 7.1 146 20

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Conclusions

June 16, 2015

Page 29

Identification of biorefinery components and their interacting systems are

key to understand the sustainability dimensions and devise innovative

solutions

Framework for biorefinery integration and sustainability needs to be

applied at all system levels

Useful information can be obtained from model-based understanding of

processes and their dynamics for long term decision making

System dynamics approach can help to know how much and at which rate

local renewable resources can be used in a sustainable manner to meet

local needs

Challenges

June 16, 2015

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Data generation and sharing at all system levels and scales, from biomass

characterisation and physical properties to yield and system dynamics

modelling

Model validation with field experiments

Knowledge integration from wide range of disciplines

As biorefineries evolve into complex systems, they will feature emergent

properties. We have the tools from the various disciplines and at all system

levels but need to be applied to identify and respond to new opportunities or

challenges that arise.

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Conclusions

June 16, 2015

Page 31

A systems thinking lens and an open mind is key in the creation of innovative solutions with sustainability as emergent property of the biorefinery puzzle.

June 16, 2015

Page 32

Acknowledgements

Dr Aidong Yang, University of Oxford

Prof Matthew Leach, University of Surrey

Thank you!