Optimization of Biodiesel Production from Deodar Oil Using Response Surface Methodology [RSM]

Biodiesel (fatty acid methyl ester, or FAME) can be used as an alternative fuel for diesel engines which is produced by the chemical reaction of vegetable oil or animal fat with an alcohol such as ethanol or methanol in the presence of a catalyst. The growing interest in biodiesel is because of the similarity in its properties when compared with the diesel fuel as well as various benefits it provides such as lower soot emissions, less dependency on crude oil, etc. The optimization of experimental parameters, such as catalyst concentration, molar ratio of alcohol to oil, and reaction time, on the transesterification for the production of deodar methyl ester was performed in this article. Optimization of the transesterification process of deodar oil was achieved by a three-factorial central composite design (CCD) using response surface methodology (RSM) in 20 experimental runs. The RSM was performed to determine the optimum operating conditions and to optimize the biodiesel yield. A second-order mathematical model was obtained to predict the yield as a function of molar ratio, catalyst concentration, and reaction time. The free fatty acid (FFA) content of deodar oil was 1.86% which is below the 2% recommended for the application of the one-step alkaline transesterification method. The optimum biodiesel yield of 98.5% was obtained by transesterification of deodar oil with 0.75 wt. % of catalysts and a methanol-to-oil molar ratio of 5 at 65°C for 34.5 min. The high biodiesel yield can be correlated to the high basicity of the catalyst.