Preparation of Biodiesel with Acid Oil in Fixed Bed Reactor by Immobilized Lipase

The transesterification of acid oil and methanol to biodiesel catalyzed by immobilized Candida lipase in fixed bed reactors was studied. The acid oil and methanol were pumped into the reactors in three-steps which were kept the molar ratio as 1∶1. The result of orthogonality experiment indicated that: the optimal conditions for transesterification of acid oil were as following:15% immobilized lipase、10% hexane and 10% water of acid oil, reaction temperature 45 ℃, flow velocity of reactant 0.8 g·min-1.The content of fatty acid methyl ester of 90.18% could be obtained under the optimal conditions.