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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
3
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
4
Biorefineries and sustainability
June 16, 2015
Page 7
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.
5
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
6
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
7
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
Page 14
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
8
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
9
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
Page 18
Biorefining
10
Case study – Local integration with ecosystems
June 16, 2015
Page 19
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
Page 20
Local area: Whitehill and Bordon, UK
11
Case study – Local integration with ecosystems
June 16, 2015
Page 21
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
12
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
Page 24
Annual cutting ratio = 0.2 Annual cutting ratio = 0.4
Ecosystem dynamics
No N recycle
13
Case study – Local integration with ecosystems
June 16, 2015
Page 25
Steady state performance
Case study – Local integration with ecosystems
June 16, 2015
Page 26
filled markers: No N recycle
open markers: with 50% of N recycle
14
Case study – Local integration with ecosystems
June 16, 2015
Page 27
Cumulative biomass harvest and nitrogen stored in soil after 50 years of
heathland management
Case study – Local integration with ecosystems
June 16, 2015
Page 28
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
15
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
Page 30
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.
16
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!