Transesterification of Castor Oil to Biodiesel by using Mg-Al Hydrotalcites as a Catalyst

Production of biodiesel via transesterification of castor oil using metal oxides as as solid catalysts is investigated. Finding a suitable catalyst that is active, selective and stable under the high free fatty acids (FFA > 0.5 %) is the major challenge. In this study, castor oil has been chosen as feedstock because it is readily available in Malaysia and non food. Castor oil is constituted mainly by triglycerides which consist of three fatty acids molecule in one molecule of glycerol. These triglycerides are converted to the corresponding alkyl ester and glycerol by transesterification with short chain alcohols; typically methanol. Heterogeneously catalyzed offers advantages over the homogeneous catalyst. Usage of homogeneous catalyst for transesterification is problematic because it can produce large amounts of unwanted soap by product, which create problem in product separation. Biodiesel production costs could certainly be reduced by using a heterogeneous catalyst for transesterification reaction instead of a homogeneous catalyst. This heterogeneous process provides higher quality esters and glycerol, which are more easily separated and further expensive refining operations are not needed. In this study,hydrotalcite derived Mg-Al mixed oxide which is a heterogeneous catalyst will be use as catalyst. The effect of reaction parameters in transesterification reaction is observed through conducting an experiment. Gas Chromatography (GC) and Gas Chromatography Mass Spectrometry (GCMS) have been used to analyze biodiesel product