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With kind permission of Dr. Howe, this presentation is reproduced here for the benefit of students of Algae biology.
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AlgalAlgal BiofuelsBiofuels and theand theAlgallgal Bioenergyioenergy Consortiumonsortium
UNIVERSITY OFCAMBRIDGE
Professor Christopher HoweDepartment of BiochemistryUniversity of Cambridge, UK
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Topics
• Energy Biosciences Research in Cambridge
• Algal Biofuels
• Algal Bioenergy Consortium
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Cambridge as a Centre for Energy Biosciences
Broad research base - fundamental strengths in:plant science and photosynthesisbiochemistrygeneticsbiotechnologyprocess engineering (bio and non-bio) and chemistryphysics and properties of plant materialsengineering performance and design of engines and gasturbinesmodelling of complex systems: high level economic andsustainability modelssocial aspects of changes in land use
Algal Bioenergy ConsortiumAlgal BiofuelsBioenergy Research Cambridge
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Cambridge as a Centre for Energy Biosciences
Broad research baseAbility to attract:
Students, staffResearch funding (£204M in research grants/contracts in 2005-6)Intellectual capital: eg Sanger Centre/ European Bioinformatics InstituteInvestment: eg Microsoft Research
Environment for innovation (e.g. Cambridge Science Park)Global outreach (e.g. Cambridge Programme for Industry)Record of deliveryAccess to non-governmental organizations (NGOs),academic institutes and industry
John Innes CentreNational Institute for Agricultural Botany (NIAB)Sainsbury laboratory (£150M from Gatsby Foundation)Rothamsted ResearchADAS (science-based rural and environmental consultancy)MonsantoNickersons
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Plant cell wall engineering
Plants engineered to contain decreased or increased quantities of hemicelluloses. Figure shows a stemsection with the different biomass components cellulose, xylan and mannan labelled in different colours.
Dr Paul Dupree - http://www.bio.cam.ac.uk/~dupree/
Algal Bioenergy ConsortiumAlgal BiofuelsBioenergy Research Cambridge
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Algal biofuels
Advantages of algae as biofuels
do not require use of agriculturally productive orenvironmentally sensitive landmarine sites also possiblehigh yields possible (>100 tonnes/ha/yr achieved;theoretical max, for local light levels (Mumbai) >500tonnes/ha/yr)some strains directly secrete hydrocarbonscan be coupled to other industrial processes (e.g.sequestration of CO2 from flue gases, removal ofnitrates/phosphates from waste water)growth can be linked to generation of high-value products(nutraceuticals, pharmaceuticals - e.g. carotenoids,phycobiliproteins)
Algal Bioenergy ConsortiumAlgal BiofuelsBioenergy Research Cambridge
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Algal biofuels
Previous studies include:
US Department of Energy Aquatic Species program: Biodiesel fromAlgae (Program 1978-1996; Close-out report July 1998)Collection of oil-producing microalgae (Hawaii)Oil production per cell higher under stress - but lower overallSome progress in algal molecular biology/transformationOpen ponds demonstratedHigh cost prohibitive, but land considerations favourable
Biofixation of CO2 and greenhouse gas abatement with microalgae -technology roadmap (Benemann JR, 2003)Restrict to open ponds, because of costIntegrate with wastewater treatment and high-value co-productsClosed reactors for inoculum production
Algal Bioenergy ConsortiumAlgal BiofuelsBioenergy Research Cambridge
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Algal biofuels
Major developments since those reports include:
Recognition of “social” cost of carbon$65 US to $905 US per tonne CO2(5-95% confidence range, PAGE 2002 model, Stern reportassumptions)
Improvements in understanding of photosynthesis biochemistry
Breakthroughs in technology for molecular biology of algae (e.g.systems for genetic modification)
Algal Bioenergy ConsortiumAlgal BiofuelsBioenergy Research Cambridge
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Algal Bioenergy Consortium (ABCABC)
Large multidisciplinary group, based in Cambridge, butwith links elsewhere including outside UK
Brings together molecular biologists, physiologists,engineers and economic analysts to work towardsoptimising algal bioenergy for commercial exploitation
Actively seeking partners with whom to collaborate todevelop & test our ideas
Algal Bioenergy ConsortiumAlgal BiofuelsBioenergy Research Cambridge
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Biology & Energy Futures LabProf Peter Nixon
Members of the ABCABC
BiochemistryChemical EngineeringEngineeringJudge Business SchoolPlant Sciences
Other Collaborators include:H+ Energy Ltd
Prof Sue Harrison (UCT, South Africa)Biology Dr Saul Purton
Biosciences Dr John Love
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Algal Bioenergy Consortium (Cambridge members)
Biochemistry Prof Chris HoweDr Derek BendallDr Beatrix Schlarb-RidleyExpertise in photosynthesis biochemistry, algal molecular biology
Chemical Engineering Mr Paolo BombelliDr John DennisDr Adrian Fisher
Engineering Dr Stuart ScottExpertise in novel techniques for carbon capture, large scalefermentation, combustion, electrochemistry
Judge Business School Dr Chris HopeExpertise in policy analysis of climate change; developer of PAGEmodel used in impact calculations in Stern Report
Plant Sciences Prof Alison SmithDr Martin CroftExpertise in algal metabolism, algal molecular biology
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Strategic Aims of the AAlgal BBioenergy CConsortium
Production ofbiomass and/orbiodiesel, CO2sequestration
Develop algae as a source of biofuels
Conversion of lightenergy into hydrogenusing biophotovoltaic
panels
“Metabolic”hydrogen production
3 priority areas
Assessment of economic feasibility
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Strategic Aims of the AAlgal BBioenergy CConsortium
Today’s presentation
Algal Bioenergy ConsortiumAlgal BiofuelsBioenergy Research Cambridge
Production ofbiomass and/orbiodiesel, CO2sequestration
Develop algae as a source of biofuels
Conversion of lightenergy into hydrogenusing biophotovoltaic
panels
“Metabolic”hydrogen production
3 priority areas
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Algal biomass
Light
Algalbiomass
Biomass can be burntdirectly
Different componentscan be extracted from
the biomass
Carbohydrate Lipids andhydrocarbons
BiodieselBioethanol /biobutanol
Different algal strains will haveDifferent algal strains will havedifferent properties and will bedifferent properties and will besuited to different end productssuited to different end products
CO2 from powerstations/other
industries
Waste waterfrom industry
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R&D focus areas
A. Efficiency of light capture
B. Photobioreactor design
C. Choice of algal strain
D. Economic modelling
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Modifying photosynthetic antenna size
Reducing the antenna size would increase the light conversion efReducing the antenna size would increase the light conversion efficiencyficiencyof algal cultures, particularly under high light conditionsof algal cultures, particularly under high light conditions
Smaller antenna Greater efficiency
Light intensity
Rate ofphotosynthesis
Wild type cells
Cells with reducedantenna size
Increasedefficiency
Focus area A B C DAlgal Bioenergy ConsortiumAlgal BiofuelsBioenergy Research Cambridge
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Lab-scale photobioreactors - possible configurations
~ 1m
Flue gases
~ 0.01m ~ 0.5 m
Flue gases
Flat plate or bank of tubes
Use of oscillatory flow topromote turbulence at lowpower consumption
Removable baffles and/or differentialsparging to allow operation as bubblecolumn or circulating “air lift” reactor
External air lift tocirculate reactorcontents, when tilted
• Need to be flexible, transportable and cheap
• Should be closed, consider ‘air-lift’ for circulation
• Easy to modularize for scaling up
Focus area A B C DAlgal Bioenergy ConsortiumAlgal BiofuelsBioenergy Research Cambridge
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Lab-scale photobioreactor – Version 0.9
• Located on roof of the EngineeringDepartment, Cambridge.
• Flat panel, bubble column reactor.
• Sequestering carbon from asimulated flue gas.
• Growing a “model” algae(Chlamydomonas)
Prototype reactor to allowexperience to be gained growingalgae out of the lab.
Aim to produce enough algalbiomass to investigateharvesting and downstreamprocessing.
0.5 m
1 m
15 % CO2 in air
0.03 m
Focus area A B C DAlgal Bioenergy ConsortiumAlgal BiofuelsBioenergy Research Cambridge
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Choice of Algal Species
A range of species is availablesatisfying different sets ofthese criteria.
Spectrum ofgrowth
characteristicsto consider
Growth rateshould be fastto maximizeCO2uptakeTemperature
hightemperatures
reduce the needfor flue gas
cooling
pHlow pH reduces
problems caused byCO2 acidification,and helps avoidcontamination
Salinityhalotolerance may
allow use ofseawater
Growth mediumshould be simple
and cheap
Cell Compositionlow N levels to
reduce NOxemissions
Focus area A B C DAlgal Bioenergy ConsortiumAlgal BiofuelsBioenergy Research Cambridge
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Economic modelling - the cost of carbon
Social cost of carbon from PAGE2002with Stern review assumptions
90534065C as CO 2
95%mean5%
$US (2000) per tonne
Source: 10000 PAGE2002 model runs using Stern review assumptions
2000 - 2200
Focus area A B C DAlgal Bioenergy ConsortiumAlgal BiofuelsBioenergy Research Cambridge
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Questions to address
Algal strain
• Nutrient requirements
• Freshwater/marine
• Ability to withstand pH, temperature changes
• Response to light quality/quantity
• Products and yields required
• Acceptability of genetically modified strains
• Single species or mixture
• Response to predators (especially if open raceways used)
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Questions to address
Reactor design/location
Simple design for cost effectiveness
Need to avoid a large parasitic power requirementCO2 introduction and circulation via air lift, turbulence or oscillatory flow
HarvestingBatch filtration and drying with available low-grade heatMechanical dewatering (e.g. continuous decanter centrifuge) with dryingExact configuration depends on outcomes, plus cost/operability analysisFate of spent medium
Characteristics of chosen siteWater availability, light quality/quantity, temperature, (flue gas composition)
A large area must be covered to absorb a significant amount of CO2Several large reactors versus banks of modular reactors
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Strategic Aims of the AAlgal BBioenergy CConsortium (ABCABC)
Production ofbiomass and/orbiodiesel, CO2sequestration
Develop algae as a source of biofuels
Conversion of lightenergy into hydrogenusing biophotovoltaic
panels
“Metabolic”hydrogen production
3 priority areas
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Photosynthetic light reactions
PSII PSICyt b6f ATPase
FNR
PC
FD
2H2O 4H+ + O2
PQ
PQH2
NADP+ NADPH
H+
H+
ADP + Pi ATP
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Photosynthetic light reactions
-1.5
-1.0
-0.5
0.0
0.5
1.0
Platinumelectrode
2H+ H2
-420 mV
e-
PSII
PSI
hγ
2H2O 4H+ + O2
-480 mV
+420 mV840 mV
Fe(CN)6
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ν
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Semi-biological device (biophotovoltaic)
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Conclusions
• Exploitation of algae for bioenergy must be considered seriously
• Long lead-in time, e.g. in strain development, so R&D should not be delayed
• Medium term: prospects for biofuels/biomass
• Carbon capture/high value co-products makes technology more attractive
• Longer term: prospects for hydrogen generation (biophotovoltaics, metabolic)
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