Monday, April 19, 2010
LL Conference Facility (Hilton Clearwater Beach)
One area of alternative fuels that has gained a lot of interest over the last year or two is algae biodiesel, probably because they grow rapidly, are rich in vegetable oil and can be cultivated in ponds of seawater, reducing the need for fertile land and fresh water. Furthermore, some strains yield at least 15 times more oil per hectare than crops commonly used for biofuels. In this work, the efficiency of oil extraction from the microalgae Chlorella vulgaris was investigated and some methods were compared: ultrasonic-assisted extraction protocols and Soxhlet extraction method. First, the microalgae Chlorella vulgaris was cultivated in Guillard f/2 (Guillard, 1975), then they were separated from the culture media by centrifugation and dried to extract the oil. Higher yield of total lipid extracted were obtained when ultrasonic-assisted extraction methods were used: 52.49%, 16.06%, 10.86 % and 2.15%, when using Bligh and Dyer, Folch, Chen and Hara & Radin protocols, respectively. The lowest yield was obtained for the Soxhlet method, 1.67%. The Bligh and Dyer ultrasonic-assisted extraction method was used to extract the oil that was used in the transesterification reaction, enzymatic route of biodiesel production, using Rhizomucor miehei lipase supported on chitosan activated with glutaraldehyde. The chemical composition of alkyl esters produced was obtained with a gas chromatograph coupled to a mass spectrum (GC-MS).