10. Investigation of Coconut Methyl Ester (CME)-Palm Oil Methyl Ester (POME)-Diesel Blends Volatility

A poorer combustion quality of biodiesel compared to diesel fuel has led to a low cylinder pressure of compression ignition engines, increased fuel consumption, and reduced fuel efficiency. Most of the biodiesel boiling point curves are almost flat without slope. In fact, fast evaporation of fuel may lead to more intense heat release if a higher percentage of the fuel is mixed with air to form a combustible mixture. An increasing boiling curve is beneficial for good fuel ignition and combustion in the cylinder. In this study, the coconut oil methyl ester (CME)-palm oil methyl ester (POME)-diesel blends boiling curve is investigated. The fuel samples were prepared and characterized by distillation curves and gas chromatography. CME was produced by the transesterification method and the result shows fulfills ASTM 6751 and EN 14214 standards, except for the CME flash point that lower than its standards. However, a low flash point has the benefit of reducing the ignition delay which can improve the ignition process and combustion. The result also shows CME is more volatile compared to POME. The blending of diesel to POME has improved the distillation of the fuel behavior. In order for an ideal fuel distillation curve, the maximum blending CME into diesel is 20% (DCME20). PCME50 and PCME45 show a good trend of the distillation curve for improvement of biodiesel volatility.