Biomass Production and Ester Synthesis byIn SituTransesterification/Esterification Using the MicroalgaSpirulina platensis

The increasing energy demand and reduction in the availability of nonrenewable energy sources, allied with an increase in public environmental awareness, have stimulated a search for alternative energy sources. The present study was aimed at producing biomass from the microalga Spirulina platensis and at assessing in situ synthesis of alkyl esters via acid transesterification/esterification of biomass to produce biodiesel. Two alcohols (ethanol and methanol) and two cosolvents (hexane and chloroform) were tested, at different temperatures (30, 45, 60, 75, and 90°C) and reaction times (10, 20, 30, 60, and 120 min). The factorial analysis of variance detected an interaction between the factors (): temperature, reaction time, alcohol, and cosolvent. The best yields were obtained with the combination ethanol and chloroform at 60°C, after 30 min of reaction, and with hexane at 45°C, after 10 min of reaction. In situ transesterification/esterification of alga biomass to form esters for biodiesel production adds unconventional dynamics to the use of this feedstock