ENZYMATIC PRODUCTION OF BIODIESEL FROM RAPESEED OIL

Abstract

SUMMARY Enzymatic transesterification has attracted much at tention for biodiesel production as it produces high purity product and enables easy separ ation from the by product, glycerol. But the activity of immobilized enzyme is inhibited by methanol and glycerol which are present in the reacting mixture. The use of t-butanol as so lvent has been found to reduce the inhibitory effects [1,2]. In this paper, results of methanolysis of rapeseed oil by Novozym 435 as catalysts using t-butanol as a solvent, are reported. The enzyme Novozym 435, an immobilized Candida Antarctica lipase, was bought from Novozymes Austria. Reference standards for FAMEs, together with the rapeseed oil used as substrate, were obtained from Sigma. The fa tty acids composition of oil was determined by a GC-FID method.. Enzymatic esterification reactions were carried out for 12h in a 100 ml round-bottomed flask, equipped with a t emperature controller. The stirring rate was adjusted to 700 rpm. Reaction conditions: t-butanol/oil volume ratio 1:1; methanol/oil molar ratio 4:1.The effects of lipase quantity and of temperature on the alcoholysis of rapeseed oil are presented in Table 1 and Table 2.