Sunday, April 29, 2007

Biodiesel synthesis by enzymatic transesterification of palm oil and ethanol using lipases from several sources immobilized on silica-PVA composite

Ana Beatriz R. Moreira1, Victor H. Perez1, Gisella M. Zanin2, and Heizir F. de Castro1. (1) Engineering School of Lorena, University of São Paulo, P.O.Box 116, Lorena - SP, 12602-810, Brazil, (2) Chemical Engineering Department, State University of Maringa, Av. Colombo, 5790, BL E-46, Maringa - PR, 87013-190, Brazil

Esters from vegetable oils are the best substitutes for diesel because they do not demand any modification in the diesel engine and have a high energetic yield. It is usually produced by a transesterification reaction of vegetable oil with a low molecular weight alcohol, such as ethanol and methanol. Industrially, the most common method for biodiesel production is a basic homogeneous reaction, although, there has been a continuous development of new catalysts, especially for heterogeneous processes, such as immobilized lipases.

 This work presents the transesterification of palm oil with ethanol in a solvent free system using lipase from different sources (porcine pancreatic, Thermomyces lanuginosus, Pseudomonas fluorescens, Burkholderia cepacia, Penicillium camembertii and Candida antarctica)  immobilized on hybrid support polysiloxane-polyvinyl alcohol. This is an exceptional option for the Brazilian biodiesel production, since both palm oil and ethanol are ready availability in the country. 


The enzyme source showed strong influence on the transesterification yields and best performance was attained with the lipase from Pseudomonas fluorescens, which reached 90% conversion in less than 48 hours of reaction. The viscosity of the reaction medium in the order 3.5 cp demonstrated that the final product fulfill the specifications for its use as biofusel.