Combustion Characteristics of a DI Diesel Engine with Palm Kernel Oil Biodiesel and Its Blend (B20)

The fuel properties, the diesel combustion and the exhaust emissions of palm kernel oil methyl ester (PKME) and a blend of 20% PKME with 80% JIS No.2 gas oil (PK-B20) were investigated. In this study, the fuel properties were measured by laboratory analyses and the engine experiments were carried out by using a single cylinder direct injection diesel engine. To make comparison between biodiesels and conventional diesel fuel, palm oil methyl ester (PME), coconut oil methyl ester (CME), and the gas oil (JIS No.2) were also used as test fuels. From the fuel property analyses and the engine experimental results; the pour point of PKME was -5°C which was the same as that of CME and the pour point of PK-B20 was -10°C, the brake thermal efficiency of PKME was the same as the other test fuels, the ignition ability of PKME was better than that of the gas oil and the exhaust emissions (CO, HC, NOx and smoke) from PKME were almost the same as those of CME and lower than those of the gas oil. Specifically, at 100% load condition, about 47% reduction in smoke emission was found in PKME compare to that of the gas oil.