Castor oil biodiesel production and optimization

Biodiesel is evolving to be one of the most employed biofuels for partial replacement of petroleum based diesel fuel, especially in recent years. The most widely used feedstocks for biodiesel production are vegetable oils. In this work, biodiesel production from castor oil has been synthesized by homogenous alkaline transesterification. The influence of catalyst concentration, methanol:oil molar ratio, reaction temperature and reaction time in the methyl ester content reached by castor oil transesterification have been evaluated. A yield of 95 wt% biodiesel was achieved at 1 wt% KOH, 60 °C, 9:1 methanol:oil ratio and 30 min reaction time. Transesterification at temperature 30 °C gave a yield compatibles with that obtained at 60 °C. The composition of the fatty acid methyl ester was determined by Gas Chromatography. The castor oil biodiesel produced was blended with different concentrations of petrodiesel to obtain B5, B10 and B20. The biodiesel properties and its blends were determined according to the standard test methods of analysis. The results showed that Castor oil biodiesel in the blends could lower the cloud point value, but simultaneously, increases the viscosity of the diesel–biodiesel blends. Thus, castor oil biodiesel with its very low cloud and pour points is suitable for using in extreme winter temperatures.