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Biofuels from algae
Shannon Ewanick
CFR 521
April 29, 2008
Introduction
Background
Processes
Conclusion
Background
Uses for algaeNutrition
• Nori, dulse, kombu• Supplements – spirulina, chorella• DHA
CosmeticsFertilizerAquaculturePigments
Bioproducts
BiodieselAlgae biodiesel has superior cold-weather
properties Vegetable oil Bioethanol Butanol Methanol Hydrogen
Requirements
Light CO2
Water Inorganic nutrients
Vary depending on algaeNitrates, phosphates, iron, trace elements
Farming methods
Photosynthetic surface area
Surface area to volume ratio (SVR)Open (pond) system: 3-4 m2/m3
Closed system 70-100 m2/m3
3D matrix system 1500-2000 m2/m3
SurfacesPolycarbonate (best)AcrylicGlassPolymer film
Process
Algae biomass production
CO2
NutrientsBiomass recovery
Extraction
Water, nutrients
Oil
Biomass
Biodiesel
BioethanolAnimal feedBiogas
Algae species
Many different species can be used Different species for fresh or salt water
Scenedesmus dimorphus • High yield but needs constant agitation
Botryococcus braunii • Produces long chain hydrocarbons, up to 86% of weight• Thought be responsible for fossil fuel deposits
Chlorophyceae spp.• Produce starch granules
Productivity
NREL
Challenges
“High yield photoefficiency”As biomass increases light access is blockedUse small diameter tubes
High capital costs Contamination by invasive species Water must be maintained at constant temp. Not enough CO2 in atmosphere for exponential
growth
Disadvantages
Transfers CO2 – doesn’t eliminate it
Captured CO2 from coal plants is released by cars
Could slow progression towards alternative energy sources which might reduce CO2 levels
High water usage Nutrient sourcing
Production
PetroSun: Rio Hondo, Texas 1100 acres of saltwater ponds 4.4 million gallons oil/year 110 million pounds biomass/year
Solix 0.4 acre pilot plant using CO2 from brewery Flexible plastic reactors – 50x300 ft Predict 8000 gal/acre/year
Players
Greenfuel Technologies Corp. PetroSun Solix Algaelink Solazyme Valcent
Conclusions
Cost of “alg-oil” becoming more reasonable as oil prices rise
Best constructed in tandem with a CO2 producer
Promising “piece of the puzzle” for future transportation fuels
Questions?