As a novel strategy, blended alcohols consisting of methanol and ethanol were used as acyl acceptors for biodiesel synthesis from soybean oil by lipase-catalyzed transesterification. Based on enzyme screening, Novozym 435 from Candida antarctica was selected for the reaction. The effects of the molar proportion of methanol in the blended alcohol, temperature, and enzyme loading were investigated for optimization of the reaction. In addition, the relative consumption rates of methanol and ethanol during the transesterification were studied. Among six proportions tested, 0 (100 mol% ethanol), 20, 40, and 60 mol% methanol in the blended alcohols exhibited high yields of biodiesel. For the optimum temperature, 30 °C was selected. The highest yield of biodiesel, over 95 wt%, was obtained at an enzyme loading of 5-10 wt% loading. In the lipase-catalyzed transesterification, the reactivity of methanol was significantly higher than that of ethanol.
- Blended alcohol