Production of Biodiesel Using Immobilized Lipase and the Characterization of Different Co-Immobilizing Agents and Immobilization Methods

Kang Zhao,Li Deng,Fang Wang,Xi Cao,Meng Wang,Qinjian Di

doi:10.3390/su8090764

Abstract

Lipase from Candida sp. 99–125 is widely employed to catalyzed transesterification and can be used for biodiesel production. In this study, the lipase was immobilized by combined adsorption and entrapment to catalyze biodiesel production from waste cooking oil (WCO) via transesterification, and investigating co-immobilizing agents as additives according to the enzyme activity. The addition of the mixed co-immobilizing agents has positive effects on the activities of the immobilized lipase. Three different immobilizing methods were compared by the conversion ratio of biodiesel and structured by Atom Force Microscopy (AFM) and Scanning Electron Microscopy (SEM), respectively. It was found that entrapment followed by adsorption was the best method. The effect of the co-immobilizing agent amount, lipase dosage, water content, and reuse ability of the immobilized lipase was investigated. By comparison with previous research, this immobilized lipase showed good reuse ability: the conversion ratio excesses 70% after 10 subsequent reactions, in particular, was better than Novozym435 and TLIM on waste cooking oil for one unit of lipase.

Highlights

Biodiesel, defined as monoalkyl esters of long chain fatty acids, is environmentally friendly and shows great potential as an alternative liquid fuel [1,2]. It is usually produced by transesterification of plant oils or animal fats with chemical catalysts or lipase
Lipase catalyzed biodiesel production is currently a very interesting topic as it allows the use of rather mild reaction conditions which is eco-friendly [4,5]
The use of additives has been reported as method to increase the catalytic activity of the lipase

Summary

Introduction

Biodiesel, defined as monoalkyl esters of long chain fatty acids, is environmentally friendly and shows great potential as an alternative liquid fuel [1,2]. It is usually produced by transesterification of plant oils or animal fats with chemical catalysts or lipase. The lipase immobilized by entrapment is much more stable than physically adsorbed lipase The problems such as leakage of the enzymes during continuous use and insufficient substrate-enzyme interactions still have to be faced [9]

Methods

Results

Conclusion