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Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Optimization and screening of product portfolios in algo-biorefinery value chains: from research through
development to scale-up
A. Kokossis(1) and D. Rooke(2)
(1) Chemical Engineering School, National Technical University of Athens, Greece
(2) Dynamic Extraction, UK
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Outline
• Why screening?
• Design in the context of the biorefinery concept: challenges and limitations of the evolutionary approach
• D-Factory: a systems approach to development and scale-up
• Implementation, customization and generalization
• An open access offer to the community
• Future work & conclusions
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Refineries & biorefineries
• Similarities to chemical Industries
• Holistic and parallel exploitation of supplies;
• gradual evolution, integration and innovation to exploit ‘every drop of biomass’ into a useful product
• Biorefineries: similar but more general problems
• Multiple products, feedstocks, processes
• Rich knowledge maps behind conversion paths
• regional variability and seasonality
• Drive towards local rather global solutions with additional incentives to exploit other renewables
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Biorefinery challenges in a nutshell• Synthesis challenges:
• Large combinatorial problem: product against feedstocks and technologies
• Process integration challenges:
• Raw material utilization, energy recovery, environmental performance
• Centralized vs distributed production
• Modelling and flowsheeting challenges:
• Capture data from the lab and experiments
• Opportunities for novel process equipment
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Process design in the context of biorefineries
• Conventional process design: start with
• start with
• Product and often a feedstock; chemistries and conversion paths
• Design, develop and integrate processing tasks
• Select and integrate economic processing paths; scale-up and cost the process to assess its economic viability
• The case of biorefineries
• How close are we set to such a description?
• Does the processing of impose algae additional constraints?
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
D-Factory value chain
• Which products to target? Which ones from each building block?
• Complementary integration schemes?
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Challenges• Holistic use implies multi-product biorefineries
• Integration is possible within a process, across different processes also considering the full plant
• Largest promise from non-energy products: short life cycles, volatile prices
• Process equipment could/should be reconfigured to process other algal strains, not only one particular case
• The future plant has to be flexible as specialties could gain additional value in the future (e.g. formulation into useful end-user products) or have their prices drop (e.g. expiration of licenses, competition etc)
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Selection of product portfolios: how about a straightforward evolutionary approach?
… Start with a product (one of your choice)
… Evolve the design to incorporate additional products
… continue this way, step-by-step, towards a multiproduct biorefinery
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Let’s start where the history started from…
Cultivation
Harvesting Oil extraction
Product recovery
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Introduce new product: b-carotene
▪ Conditions in osmotic tanks do not favor co-production.
▪ Settling tanks are redundant.
▪ Scope to replace spray dryers and belt press
▪ Provided that protein meal is used as food supplement (e.g. fishmeal), solvents have to be replaced
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
New result: excellent but process engineering changes are too many…
• Venture is profitable but integration scheme is very different • Retrofitting the first scheme to the second is not economical
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Next: introduce xanthophylls and galactolipids…
1 2
3
1 Glycerol, carotenes mixture
2 Glycerol, pure carotenes, pure xanthophylls
3 Glycerol, pure carotenes, pure xanthophylls, galactolipids
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
New result: similar, simply more pronounced..
• Profitability improves as you add products BUT• Integration and processing paths differ dramatically so that
retrofitting the plant is essentially impossible• Selection of new products to produce never straightforward
1
2
3
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
The evolutionary approach to process development could turn into
a free fall to the Death Valley
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
The D-Factory systems approach
… Combine state-of-the-art of systems engineering (synthesis, process integration, advanced flowsheeting..)
… Capitalizes on advanced modelling and optimization
… Possible to generalize and scale-up into very large problems
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Flexible, sustainable plants
sStrains
Screening and process
development
Select product portfolios
Stage I: Synthesis
Select technologies,target efficiencies , Stage II: Process
integration
Process flowsheeting, process development
Stage III: Costing & analysis
Steps of the systems methodology
• High-throughput screening• Could address uncertainty analysis• User interaction with decision-support process
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Stage I – Screening: methodological approach
• Model based approach where optimization technology is used to select the appropriate options
• Basic idea: combine all possible options into one model (superstructure)
• Possible does not mean exhaustive; combines knowledge from different domains
• Combinations may be encouraged or prohibited according to practical constraints
• Optimize model against selected objectives to screen and prioritize options
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
So, what we screen for?
• Quantities and qualities of algal paste
• Separation technologies
• Membranes
• Supercritical CO2 extraction
• Solvent extraction
• Chromatography
• Sequencing of separation (processing stages)
• Products and product portfolios
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Some of the D-Factory options…
Feedstock Processes Products
Ultrafiltration membrane (solid-liquid, liquid-liquid)
Nanofiltration membrane
Ethanol extraction (solid-liquid, liquid-liquid)
Heptane extraction (solid-liquid, liquid-liquid)
ScCO2 extraction (solid-liquid, liquid-liquid)
H2O extraction
HPCCC
Dunaliella paste
GlycerolCarotenoids▪ cis β-carotene▪ trans β-carotene▪ other carotenes▪ zeaxanthin▪ lutein▪ violaxanthin▪ phytoene
Lipids▪ pufas▪ chlorophyll a▪ chlorophyll b▪ EDK vitamins
Proteins▪ glycerol enzymes▪ carbonic anhydrase
.
.
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Building the screening model…
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
… and optimizing value chain and technology selection
25-27/11/2015 XXIV Month Meeting, Monzón - Spain
Paste
1_hep_extr_SL
2_solv(a)_extr_SL scCO2_extr_LL
sep_1 HPCCC_1
algae_4 car_lip
proteins residue
H2O_extr
glyc_enzymes
carb_anhydrase
lip car
pufas
EDK
chlor_a
chlor_b caroteneszeaxanthin
violaxanthin
cis_b_car
lutein phytoene
trans_b_car
Best solution
o 6 processes
o 13 products
o Equipment cost = 11000 M$/yr
o Profit = 87300 M$/yr
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
… pointing to backup optionsPaste
1_solv(a)_extr_SL
2_eth_extr_SL
sep_1 HPCCC_1
proteins algae_1
residue
H2O_extr
glyc_enzymes carb_anhydrasegl_car_lip
pufas
EDKchlor_a
chlor_bcarotenes
zeaxanthin
violaxanthin
cis_b_carlutein phytoene
trans_b_car
hep_extr_LL
car_lip
scCO2_extr_LL
lip car
glycerol
Best solution including glycerol
o 7 processes
o 14 products
o Equipment cost = 11500 M$/yr
o Profit = 86600 M$/yr
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Paste
1_solv(a)_extr_SL
2_eth_extr_SL
sep_1 HPCCC_1
proteins algae_1
residue
H2O_extr
glyc_enzymes carb_anhydrasegl_car_lip
pufas
EDKchlor_a
chlor_bcarotenes
zeaxanthin
violaxanthin
cis_b_carlutein phytoene
trans_b_car
hep_extr_LL
car_lip
scCO2_extr_LL
lip car
glycerol
Best solution including glycerol
o 7 processes
o 14 products
o Equipment cost = 11500 M$/yr
o Profit = 86600 M$/yr
… or customized around preferences for specific products or technologies
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Multiple solutions
Study the impact of process/product selection on the profit
Plotting the ‘big picture’
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
‘Popular technologies’
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
CarotenoidsLipidsProteins
Popular products and product portfolios
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Stage II – Process and energy integration
• Energy integration
• Set targets ahead of design
• Process integration as well as process to process integration (across different paths)
• Water integration
• Set targets ahead of design
• Propose re-use, regeneration, recycle strategies
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Energy integration
Cold streams Need heating
Hot streams Need cooling
Solution 1
Solution 2
Solution 3
Energy analysis per solution
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Energy use
Energy intensive processes:
→ centrifugation
→ distillation
Why:
✓ large quantities of water
✓ high purity separation
Energy sensitivity0112233
Ener
gy (
MW
) Solution 2
012345678
Ener
gy (
MW
)
Solution 3
Energy integration
0
1
2
3
4
5
6
Ener
gy (
MW
)
Base case
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Base case
StreamFlow
[kg/hr]
Recycle
ratio
Feed from
pond131.626
99.9%Recycle 131.544
To process 82
StreamFlow
[kg/hr]
Recycle
ratio
ETHANOL 25077.2%
RECYCLE 193
StreamFlow
[kg/hr]
Recycle
ratio
Fresh
Water3000
99.9%
Recycle 2997
Water cycle Ethanol cycle Hexane cycle
Water and solvent re-use and regeneration
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Stage III – Costing and economic analysis
• Flowsheeting using commercial packages
• Aspen Plus, Hysis, SuperPro, UniSim
• Emphasis on simulation: at this stage most decisions are made
• Costing and profit analysis
• Combination of empirical and commercial models
• Large uncertainty in market sizes and prices due to the novelty of the products
• Screening platform could be of critical importance to assess market volatility and uncertainty
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Flowsheeting from commercial packages…Algae-biorefinery yields
(1100 tn/yr algae paste)
Product tn/yr
glycerol 300
α-carotene 9
β-carotene 70
xanthophylls 8.8
galactolipids 90
Solution 1
Solution 2
Solution 3
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
…down to process layout
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Scenario 1
Equipment cost (M$)
13
Total operating cost (M$/yr)
13.2
Total capital cost (M$)
65.8
Revenue (M$/yr) 57.4
Scenario 2
Equipment cost (M$)
16.9
Total operating cost (M$/yr)
24.1
Total capital cost (M$)
82.8
Revenue (M$/yr) 100.5
Scenario 3
Equipment cost (M$)
17.2
Total operating cost (M$/yr)
19.3
Total capital cost (M$)
88.8
Revenue (M$/yr) 100.6
Product portfolio:
o Glycerol
o Carotene mixture
Product portfolio:
o Glycerolo Β-caroteneo A-caroteneo Luteino Zeaxanthino Violaxanthino Phytoene
Product portfolio:
o Glycerolo Β-caroteneo A-caroteneo Luteino Zeaxanthino Violaxanthino Phytoeneo MGDG
Cost summaries
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Scenario 1
Equipment cost (M$)
13
Total operating cost (M$/yr)
13.2
Total capital cost (M$)
65.8
Raceway ponds
CentrifugeSolvent
extraction S-L
Solvent extraction
L-L
0
1
2
3
4
5
6
7
8
0
1
2
3
4
5
cultivation pond centrifuge solvent extractionL-L
solvent extractionS-L
Op
era
tin
g co
st (
$/y
r)
Equ
ipm
en
t co
st (
M$
)
Process
Equipment Operating
Breakdown of equipment cost
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Raceway ponds
CentrifugeScCO2
extraction S-L
HPCCC
Solvent extraction
S-L
Nanofiltration
Ultrafiltration
Scenario 2
Equipment cost (M$)
16.9
Total operating cost (M$/yr)
24.1
Total capital cost (M$)
82.8
0
2
4
6
8
10
12
0
1
2
3
4
5
Op
era
tin
g co
st (
$/y
r)
Equ
ipm
en
t co
st (
M$
)
Process
Equipment Operating
Breakdown of equipment cost (2)
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Scenario 3
Equipment cost (M$)
17.2
Total operating cost (M$/yr)
19.3
Total capital cost (M$)
88.8
012345678
0
1
2
3
4
5
Op
era
tin
g co
st (
$/y
r)
Equ
ipm
en
t co
st (
M$
)
Process
Equipment Operating
Raceway ponds
CentrifugeSolvent
extraction S-L
HPCCCScCO2
extraction L-L
Nanofiltration
UltrafiltrationSolvent
extraction S-L
Breakdown of equipment cost (3)
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
A typical breakdown?
Investment policies could make a difference!
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Short payback times possibly hide…
… optimistic selling price of products
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Systems platform for screening
• What is made up from?
• Data (properties: thermodynamic, transport, economic, environmental)
• Models (Stage I: synthesis models and optimization; Stage II: process integration; Stage III: process flowsheets)
• Knowledge and workflows (value chain; also to include product reports, images etc.)
• The integration constitutes knowledge asset to share (or sell) to third parties
• Empowered by ontology engineering
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
User access: looks-and-feel
• New technologies and products can be included• Preferences to select/deselect technologies or products
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Optimization and screening
• Further access: technological/economic data• Analytics: compares solutions, breakdown cfc costs etc
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Generalization
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Generalization
A
A1 A2
A3 A4 A5
B
1. Formulate value chains
2. Identify common fractions
3. Customize product portfolios
Product selection:
• Market needs• Price• Amount• Non competitive
4. Integrated value chain
B1 B2 B3
B4 B5 B6 B7
Algae characteristics:
• Common properties• High value chemicals as products
A1 B3
A4
Β1
A5 B5 B6
A1/B3
A/B
A2 B3B1
A4 A5 B5 B6
P1P2 P3
P4
P5 P6 P7 P8
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Biorefineries made up by different strains
Microalgae feedstock
▪ Dunaliella▪ Haematococcus▪ Nannochloropsis
Target products
▪ B-carotene▪ Astaxanthin▪ Lipids
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Biorefinery I: Dunaliella
Resistant to potential pollutants
Growth in medium with high NaCl conc.
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Biorefinery I: Dunaliella
Capital cost (M$) 89
Operating cost (M$/yr) 31.2
Revenue (M$/yr) 126.6
B-carotene = 94% of revenue
4
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Biorefinery II: Haematococcus
Resistant species with thin cell wall
Cells adaptable to external conditions by morphological adjustments
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Biorefinery II: Haematococcus
Capital cost (M$) 80
Operating cost (M$/yr) 25.7
Revenue (M$/yr) 108
Astaxanthin = 80% of revenue
4
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Biorefinery III: Nannochloropsis
Can store large amount of lipids
Great candidate for outdoor mass cultivation
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Biorefinery III: Nannochloropsis
Capital cost (M$) 96.7
Operating cost (M$/yr) 35.1
Revenue (M$/yr) 44.2
Proteins = 50% of revenueViolaxanthin = 37% of revenue
3
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
A flexible biorefinery of the future
Potential for min. 10 products
83.3% process overlap
Cultivation ponds
Water Nutrients
Centrifugation DryingCell
extractionLiquid
extraction
Remainingcell
extraction
HPCCC
Membrane
Glycerol Lipids
CarotenoidsLipids
Proteins
Algae Biorefineries for Europe – Towards a Sustainable Economy 17-18 October, Brussels
Conclusions
• Biorefinery design and optimization brings forward new and important challenges
• Screening and scoping is important to preview opportunities ahead of detailed developments
• One could use the technology to build significant flexibility and robustness that would prevent unsuccessful investment
• The D-Factory remains a particularly promising platform to invest also possible to incorporate other strains and culture
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