Combustion Characteristics of Rice Bran Oil Derived Biodiesel in a Transportation Diesel Engine

The methyl esters of vegetable oils, known as biodiesel are becoming increasingly popular because of their low environmental impact and potential as a green alternative fuel for diesel engine and they would not require significant modification of existing engine hardware. Methyl ester of rice bran oil (ROME) is derived through transesterification process. Previous research has shown that ROME has comparable performance, lower bsfc in comparison to diesel. There was reduction in the emissions of CO, HC, and smoke but NO_x emissions increased. Experimental investigations have been carried out to examine the combustion characteristics in a direct injection transportation diesel engine running with diesel, and 20% blend of rice bran methyl ester with diesel. A Mahindra & Mahindra make four cylinder direct injection diesel engine (MDI 3000) was fully instrumented for the measurement of combustion pressure, rate of pressure rise and other in-cylinder parameters such as rate of instantaneous heat release, cumulative heat release rate, mass fraction burned etc. Tests were performed at different loads ranging from no load to 100%, at constant engine speed. A careful analysis of heat release and other combustion parameters has been done, which gives precise information about the combustion process, when using biodiesel.