Improvement strategies for the enzymatic production of biodiesel in the presence of primary alcohols

Abstract

In order to improve the enzymatic production of biodiesel, the reuse of an immobilized preparation of Candida antarctica lipase B (CALB) was assayed under di ff erent conditions. The improvement included: (1) reuse of CALB in the presence of ethanol (EtOH), (2) reuse of CALB in the presence of methanol (MeOH), (3) blended alcohols at di ff erent molar ratios (0:100, 20:80, 40:60, 50:50, 60:40, 80:20 and 100:0, %EtOH:%MeOH), and employing second generation raw materials: waste cooking oil (WCO) and castor oil (CO). When the first strategy was carried out the FAEE (fatty acid ethyl ester) content achieved was 96% in a first cycle but after four cycles the percentage decreased to 32%. For the second strategy the FAME (fatty acid methyl ester) content attained was 63% in a first cycle but after four cycles the percentage was only 13.5%. When the blended alcohols were tested, the negative e ff ect of MeOH was evident for higher concentrations regardless the type of oil used