(202e) Conversion of Microalgae to Biodiesel at Supercritical Conditions

Biodiesel derived from oil crops is a potential renewable and carbon neutral alternative to petroleum fuels. Unfortunately, biodiesel from oil crops, waste cooking oil and animal fat cannot realistically satisfy even a small fraction of the existing demand for transport fuels. As demonstrated in this work, microalgae appear to be a viable source of renewable biodiesel that is capable of meeting the global demand for transport fuels. Biodiesel from microalgae using supercritical methanol method and conventional alkali transesterification were studied in detail. A non-catalytic biodiesel production route with supercritical methanol has been developed; it allows a simple process and high yield because of simultaneous transesterification of triglycerides and methyl esterification of fatty acids. The most important variables affecting the methyl ester yield during the transesterification reaction are the molar ratio of alcohol to vegetable oil and the reaction temperature. The fuel properties of biodiesel produced were compared with ASTM standards for biodiesel and regular petroleum diesel.