Synthesis of fatty acid methyl esters using mixed enzyme in a packed bed reactor

Fatty acid methyl esters were synthesized from palm fatty acid distillate (PFAD) and methanol in a packed bed reactor via lipase-catalyzed esterification. The PFAD consisted of 91 wt% of free fatty acids, 2 wt% monoacylglycerides, 3 wt% diacylglycerides, and 4 wt% triacylglycerides. t-Butanol was employed as a reaction medium and a mixed enzyme consisting of Lipozyme TL IM from Thermomyces lanuginosus and Novozym 435 from Candida antarctica was employed as the biocatalyst. The effect of mixed enzyme was investigated and the optimum blending ratio (w/w) of Novozym 435 to Lipozyme TL IM was 5:95. Using the mixed enzyme, the optimum molar ratio (PFAD to methanol) and temperature were determined to be 1:6 and 30℃, respectively. Under the optimized conditions, the maximum yield of ca. 96% was achieved.