Combustion Characteristics of Diesel Engine with Coconut Oil Ethyl Ester

In order to use coconut oil as an alternative diesel fuel, the combustion characteristics and exhaust emissions of coconut oil ethyl ester (CEE) were investigated using a small DI diesel engine by comparing with those of coconut, palm and rapeseed oil methyl esters (CME, PME and RME), palm and rapeseed oil ethyl esters (PEE and REE) and JIS No. 2 gas oil. From the experimental results, the pour point of CEE ( -7.5 °C) is lower than that of CME ( -5 °C), the thermal efficiency and exhaust emissions (CO, HC, NOx and smoke) of CEE are almost the same as that of CME, and at 100% load condition CEE reduces smoke emission by about 45% compared with the gas oil. Therefore it can be concluded that from a combustion point of view, CEE is a favorable alternative diesel fuel. Further studies are necessary in order to thoroughly evaluate the use of CEE as an alternative diesel fuel.