Monday, April 30, 2012
Napoleon Ballroom C-D, 3rd fl (Sheraton New Orleans)
Biodiesel is a biofuel alternative to petroleum-based fuels and has as one of its main advantages the reduction of the emission of toxic gases which are harmful to the environment. In this work the production of ethyl esters by enzymatic transesterification of canola, Jatropha and radish oils, using the lipase from Burkholderia cepacia, was carried out for their possible application as biodiesel. The experiments were performed according to a 23 factorial design with four replications at the central point. The variables studied were temperature (40 °C, 50 °C and 60 °C), molar ratio of oil:ethanol (1:6, 1:9 and 1:12) and amount of enzyme (5%, 7.5% and 10 % w/w in relation to the amount of oil). The reactions were conducted in a batch reactor, for 72 hours, with the addition of ethanol divided in three steps (at the beginning of the reaction and after 12 and 24 h). The esters produced were quantified by HPLC. The largest yields of esters for canola, Jatropha and radish (47.2%, 43.8% and 40%, respectively) were obtained at the higher temperatures investigated, indicating a higher performance of the enzyme at higher temperatures. The enzymatic activities of consumption of triacylglycerols were 149.9, 97.7 and 96.0 (U/g protein) for canola, Jatropha and radish, respectively, at the lowest molar ratio of oil:alcohol used. This result suggests a decrease in enzyme activity in the presence of higher amounts of ethanol in the reaction medium.