Two-stage processes of homogenous catalysed transesterification of high free fatty acid crude oil of rubber seed

Abstract

Biodiesel is a diesel replacement and renewable fuel that is manufactured from vegetable oils, animal fats or waste cooking oils. The production of biodiesel from edible oil is currently much more expensive than hydrocarbon-based fuel, due to the relatively high cost of edible oils. The cost of biodiesel can be reduced by using non-edible oils instead of edible oils. The purpose of the present study was to develop a method of esterification of non-edible oil like rubber seed oil (Hevea brasiliensis). The high free fatty acid content oil reacts quickly with alkaline catalysts to form soap, which prevents the separation of biodiesel and glycerol. A two-step process was used instead of the simple alkaline catalysed transesterification process. It consisted of an acid catalysed pre-processing followed by the usual alkaline catalysed process. The physical and chemical properties of biodiesel were analysed. The quantification of methyl esters were done by high-performance liquid chromatography.