Enzymatic synthesis of fatty acid methyl esters from crude rice bran oil with immobilized Candida sp. 99-125

Abstract

The non-edible crude rice bran oil was extracted from white rice bran, and then was catalyzed by immobilized lipase for biodiesel production in this study. The effects of water content, oil/methanol molar ratio, temperature, enzyme amount, solvent, number of methanol added times and two-step methanolysis by using Candida sp. 99-125 as catalyst were investigated. The optimal conditions for processing 1 g rice bran oil were: 0.2 g immobilized lipase, 2 ml n-hexane as solvent, 20 water based on the rice bran oil mass, temperature of 40 °C and two-step addition of methanol. As a result, the fatty acid methyl esters yield was 87.4. The immobilized lipase was proved to be stable when it was used repeatedly for 7 cycles. © 2010 Chemical Industry and Engineering Society of China (CIESC) and Chemical Industry Press (CIP).