Heterogeneous Catalytic Transformation of Castor-Jatropha mixed oil to produce different Grades from Biofuel

Abstract

Biodiesel is a mixture of fatty acid methyl esters (FAME) obtained from vegetable oil by the transesterification reaction. In recent years, many researchers were concentrated their effort to develop biodiesel from alternative and renewable sources to replace commercial petroleum products. Biodiesel has received increasing attention due to it’s a renewable energy resource, less polluting, superior lubricity, high cetane number, high flash point and high biodegradability, and its natural resources opposed to conventional diesel. The suitable properties of plant oils and animal fats (renewable and low sulfur, nitrogen and heavy metal content), which are made up of triglycerides with long chained fatty acid groups 16 to 24 carbon atoms, makes them ideal sources for the production of biodiesel. The transesterification reaction can be catalyzed by homogeneous or heterogeneous catalysts. The transesterification reaction by homogeneous catalyst is fast with high biodiesel conversion, but the disadvantageous of use this type of catalyst is the need of using oils which have free fatty acids and low water content to avoid saponification side reaction which decreases the biodiesel conversion %. Homogeneous catalysts are alkalis such as sodium hydroxide (NaOH), potassium hydroxide (KOH), or sodium and potassium alkoxides; acids, such as sulfuric acid and hydrochloric acid; and enzymes such as lipases.