Experimental Investigations on a Jatropha Oil Methyl Ester Fuelled Diesel Engine

Biodiesel is a non-toxic, biodegradable and renewable fuel with the potential to reduce engine exhaust emissions. The methyl ester of jatropha oil, known as biodiesel, is receiving increasing attention as an alternative fuel for diesel engines. The biodiesel is obtained through transesterification process. Various properties of the biodiesel thus developed are evaluated and compared in relation to that of conventional diesel oil. In the present investigation neat jatropha oil methyl ester (JME) as well as the blends of varying proportions of jatropha oil methyl ester (JME) and diesel were used to run a CI engine. A four stroke diesel engine having compression ratio of 17.5: 1 and developing 5.2 kW at 1500 rpm was used. Experiments were initially carried out on the engine at all loads using diesel to provide baseline data. Significant improvements in engine performance and emission characteristics were observed for JME fuel. The addition of jatropha methyl ester (JME) to diesel fuel has significantly reduced HC, CO, CO₂ and smoke emissions but it increases the NO_x emission slightly. The maximum reduction in smoke emission was observed by 35% in case of neat biodiesel operation as compared to diesel. The unburned hydrocarbon emission was drastically reduced by 53% for neat biodiesel operation.