180 likes | 1.26k Views
Biofuels from algae. Shannon Ewanick CFR 521 April 29, 2008. Introduction . Background Processes Conclusion. Background . Uses for algae Nutrition Nori, dulse, kombu Supplements – spirulina, chorella DHA Cosmetics Fertilizer Aquaculture Pigments. Bioproducts. Biodiesel
E N D
Biofuels from algae Shannon Ewanick CFR 521 April 29, 2008
Introduction • Background • Processes • Conclusion
Background • Uses for algae • Nutrition • Nori, dulse, kombu • Supplements – spirulina, chorella • DHA • Cosmetics • Fertilizer • Aquaculture • Pigments
Bioproducts • Biodiesel • Algae biodiesel has superior cold-weather properties • Vegetable oil • Bioethanol • Butanol • Methanol • Hydrogen
Requirements • Light • CO2 • Water • Inorganic nutrients • Vary depending on algae • Nitrates, phosphates, iron, trace elements
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 • Surfaces • Polycarbonate (best) • Acrylic • Glass • Polymer film
Process Biodiesel Extraction Oil CO2 Nutrients Algae biomass production Biomass recovery Biomass Bioethanol Animal feed Biogas Water, nutrients
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 • Chlorophyceaespp. • Produce starch granules
Productivity NREL
Challenges • “High yield photoefficiency” • As biomass increases light access is blocked • Use 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