Optimization of Biodiesel Production from Rubber Seed Oil with Hydro-esterification Process using Response Surface Methodology

Biodiesel is a renewable fuel that is produced from oils other than petroleum oil.Rubber seed oil is one of potential raw material for biodiesel production. The high free fattyacid content in rubber seed oil makes conventional process with alkaline catalyst unsuitable.One of the alternative process is hydro-esterification process which consists of hydrolysisstages catalysed by immobilized lipase and esterification stages catalysed by sulphuric acid.This research aims to optimize the yield of biodiesel by observing three variables: methanolto rubber seed oil molar ratio, sulphuric acid concentration, and lipase concentration usingresponse surface methodology. The cetane number at optimum yield is calculated usingBamgboye-Hansen equation that is based on methyl ester composition. The highest yield isobtained at combination of methanol molar ratio 26,2; sulphuric acid 2,56% (v/v), and lipaseconcentration 26,9% (m/m). Through the calculation of cetane number, it is found that cetanenumber for biodiesel produced in optimum condition is 46