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Algal Biodiesel. A Plausible Transportation Fuel Alec M. De Groat. Outline. Define Microalgae Discuss Triacylglycerides Outline the Research and Development View Large-Scale Production Discuss Benefits of Biodiesel from Algae Plausibility as a Fossil Fuel Replacement.
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Algal Biodiesel A Plausible Transportation Fuel Alec M. De Groat
Outline • Define Microalgae • Discuss Triacylglycerides • Outline the Research and Development • View Large-Scale Production • Discuss Benefits of Biodiesel from Algae • Plausibility as a Fossil Fuel Replacement
What is Microalgae ? • Eukaryotic • Protists • Photoautotrophs • Freshwater and Marine • Greens and Diatoms • Some Produce Useful Lipids
Triacylglycerides (TAGs) • It’s a lipid • Found in the membrane and in the cytoplasm • High energy
Nile Red • Indicates presence of lipids • Rapid test • In-situ lipid observation • Highly soluble in hydrophobic environments • Fluoresces at defined wavelengths (~570nm)
Research • Sample collection • Cultures • Growth curves • Nile red • DNA sequencing
Research… • Sample collection • Freshwater • Marine
Research… • Culture and Isolation • Is isolation a good?
Research… • Liquid culture
Research… • Growth curve • Nile red • DNA Sequencing
Large-Scale Production • Methods of large scale cultivating • Raceway ponds • Photobioreactors • Harvesting and Transesterification
Production… • Raceway ponds • Less expensive setup • Large biomass production • Evaporation • Contamination • Land area
Production.. • Photobioreactors • More controlled • Limited contamination • High biomass concentration • Less land area • Expensive setup
Production… • Cell lysing and transesterification • Methanol
Production… • Oil yield a Algae contain 30% oil (/wt) in biomass. b Algae contain 70% oil (/wt) in biomass. Source: http://journeytoforever.org/biodiesel_yield.html; Chisti (2007); Mata et al., 2009.
Drawbacks of Aquaculture • Expensive setup and processing • Nutrients such as N and P • Water • Temperature control
Benefits of Algae Farming • Year-round production • Fast biomass production • Less land area • Does not compete with food crops • Higher fuel output • Can use brackish water • Carbon neutral
Problems with Other Biofuels • Ethanol • Cash crop vs. food • High burn rate • Pollution • Hydrogen • Under-developed • Volatile • Future use • Biodiesel from crops • competition with food • Lower oil yield • Cannot meet demand
Plausibility as a Fossil Fuel Replacement • Algae derived biodiesel could replace fossil fuel based diesel fuel • 530 million m3 of biodiesel annually for the United States • 1 to 3% of total U.S. cropping land area can produce 50% of diesel fuel needs • 24% of total land using other oil crops • Oil content of algae can exceed 80% of dry mass • Oil prices are high • Should cost about $0.50/L to be competitive with petroleum diesel, ($80/barrel of oil) • Current unrest in the Middle East
Summary • Algae derived biodiesel is a plausible transportation fuel • Microalgae produce more oil than crops • Microalgae can be cultivated quickly • Algae do not compete with food sources • Carbon neutral • Too expensive in the past • Methods have been used for 40+ years
Works Cited • Chisti, Yusuf. (2007) Biodiesel from Microalgae. Biotechnology Advances 25, p.294-306 • Deng, Xiaodong; Li, Yajun; Fei, Xiaowen. (2009) Microalgae: A Promising Feedstock for Biodiesel. African Journal of Microbiology Research vol. 3 p. 1008-1014 • Duffy, Emmett J.; Canuel, Elizabeth A.; Adey, Walter; Swaddle, John P (2009) Biofuels: Algae. Science vol. 326 no. 5958 p. 1345 • Elsey, Danielle; Jameson, David; Raleigh, Barry; Cooney, Michael J. (2007) Fluorescent Measurement of Microalgal Neutral Lipids. Journal of Microbiological Methods 68, p.639-642 • Greenwell, H.C.; Laurens, L.M.L; Shields, R.J.; Lovitt, R.W.; Flynn, K.J. (2009) Placing Microalgae on the Biofuels Priority List: a Review of the Technological Challenges. J.R. Soc. Interface doi: 10.1098/rsif.2009.0322 • Janssen, Marcel; Tramper, Johannes; Mur, Luuc R.; Wijffels, Rene' H. (2002) Enclosed Outdoor Photobioreactors: Light Regime, Photosynthetic Efficiency, Scale-Up, and Future Prospects. Biotechnology and Bioengineeringvol 81 issue2 • Mitchell, Donald (2008) A Note on Rising Food Prices. The World Bank Development Prospects Group • Pimentel, David; Patzek, Tad W. (2005) Ethanol Production Using Corn, Switchgrass, and Wood: Biodiesel Production Using Soybean and Sunflower. Natural Resources Research vol.14 no.1 p.65-78