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 engines. They do not require significant modification in existing engine hardware. Methyl ester of rice bran oil (ROME) is prepared through the process of transesterification. 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. In the present research, experimental investigations have been carried out to examine the combustion characteristics of a direct injection transportation diesel engine running with diesel, and 20% blend of ROME with diesel. A four-stroke, four-cylinder, direct-injection transportation diesel engine (MDI 3000) was fully instrumented for the measurement of combustion pressure, rate of pressure rise and other combustion parameters such as instantaneous heat release rate, cumulative heat release rate, mass fraction burned etc. Tests were performed at different loads ranging from no load to 100%, at constant engine speed. No engine hardware modification was carried out for the present study. A careful analysis of combustion and heat release parameters has been carried out, which gives precise information about the in-cylinder combustion of rice bran oil based biodiesel vis-a`-vis mineral diesel.