Chapter 20 - Biofuel Production

Abstract

Although vegetable oil could be used directly as fuel in diesel engines, the most important limitation lies in the fact that high viscosity of vegetable oils results in poor atomization in the engines combustion chamber which eventually leads to other operational problems. Transesterification is a catalytic route to obtain biodiesel and the catalyst could be an acid, base in homogeneous and heterogeneous forms or by enzymatic reaction. Use of alkaline catalysts may cause side reaction such as saponification and consequently entrapment of the produced biodiesel in the produced soap. Homogeneous acid catalysts on the other hand resist to high FFA content of the feedstock and could catalyze both transesterification and esterification reactions simultaneously. Corrosion problem caused by acid catalysts as well as high oil to alcohol ratio requirement caused to depend on heterogeneous catalytic with highly preformed process.