Enzymatic Production of Biodiesel from Millettia pinnata Seed Oil in Ionic Liquids

Abstract

Millettia pinnata seed oil has been identified as a promising sustainable feedstock for biodiesel production. Oils extracted from the seeds grown in freshwater and seawater habitats showed no significant differences in their physico- chemical properties. The enzymatic methanolysis of the oil has been investigated in the ionic liquid (IL) (BMIm)(PF6 )( 1- butyl-3-methylimidazolium hexafluorophosphate) as com- pared to tert-butanol, catalyzed by Penicillium expansum lipase (PEL) and Candida antarctica lipase B (Novozym 435). Under optimal conditions, PEL induced much higher yields in the IL than in tert-butanol, while in the IL PEL- catalyzed conversions were higher than those catalyzed by Novozym 435. The catalytic processes were improved by recycling both the enzyme (Novozym 435) and the IL ((BMIm)(PF6)) and by searching for new enzymes and new ILs. The impact of ILs on biodiesel production has been discussed, and the interactions between the IL, the substrate, and the enzyme are believed to play an important role in governing the conversion.