1 algae biofuel b. greg mitchell scripps institution of oceanography university of california, san...
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Algae Biofuel
B. Greg MitchellScripps Institution of OceanographyUniversity of California, San Diego
With contributions fromSempra Utilities, Earthrise
LiveFuels, Inc, General AtomicsNeste Oil and The Scripps Research Institute
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Algae very diverse: microscopic to giant kelpEfficient, rapid growth, can double biomass in a dayProduce 50% of oxygen but are less than 1% of all plant biomass Few species have been studied for biofuel potential
Chlorophyceae Dinophyceae Bacillariophyceae
Algae are photosynthetic organisms
CO2 + H2O + Light Energy Biomass
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Ethanol and Biodiesel Feedstocks Must Be Expanded if They are to Contribute Substantially
Reliance on food crops undesirable – and Limiting
Cellulosic ethanol could be part of the solution
Ethanol and biodiesel needs a non-food feedstock
Algae Can Play that Role:
Can be grown on non-arable land in saline water
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Unique Potential of Algae Biodiesel
• Soybean Based Biodiesel will never contribute more than a few percent of the possible US diesel fuel market
• ~20 million acres of algae would supply ALL US transportation fuel– Small fraction of current land use– US currently uses ~970 million
acres for crops & grazing
CropGal/Acre/yrOf Oil
Soybean 48
Peanuts 113
Rapeseed 124
Coconut 287
Palm Oil 635
Algae 15,000
Yield per acre
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ALGAE BIOFUEL – REDUCED GLOBAL WARMING & LOWERED ENVIRONMENTAL IMPACTS
• Algae requires CO2 for growth therefore fuel is carbon neutral
• Possible integration to achieve low-cost CO2 sequestration and nutrient remediation
• Uses all nutrients, minimizing eutrophication• Biodegradable, so minimal issues with accidental spills /leaks • Uses underutilized land, e.g. deserts• Yields >10x those for land plants so much less land is needed• Can grow in salt, or brackish water• Can produce high yields of
– Lipids for biodiesel– starch / polysaccharides for ethanol
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Encouraging Cost Projections Analysis by General Atomics
Costs of Biodiesel from Algae
0
500
1000
1500
2000
2500
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3500
4000
4500
0 0.5 1 1.5 2 2.5 3
$/gal diesel
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Option Rate Impact GHG Impact Market Readiness/ Issues
Biogas -
Manure, Wastewater, Stillage
Neutral to slight negative based on scale
High Ready Now; Needs scale
Microalgae Neutral to slight negative
High 5 Years; Land requirement; Tech. development
Energy Crops- Switch grass, willow hybrid poplar
TBD Medium to High 5-10 Years; Yields need to improve; land requirement and logistics issues
Biomass Pyrolysis and gasification – Forestry Residue
Negative Medium Needs significant development and scale economies for commercialization
Evaluation of various Biofuel Options Sempra Utilities
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Engineering a Photosynthetic Hydrocarbon MixSteve Mayfield The Scripps Research Institute
Potential to convert light energy directly to fuel molecules
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Vision for a Center of Excellence for algae bio-energy research, development and demonstration
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Earthrise Algae FarmCalipatria, Ca
Salton Sea
Feasibility of algae farming proven
Scale up for biofuel will be a challenge