Performance Evaluation of a Biodiesel (Rice Bran Oil Methyl Ester) Fuelled Transport Diesel Engine

This experimental study was undertaken to investigate the use of vegetable oil derivatives to substitute mineral diesel fuel. Straight vegetable oils pose some problems like injector coking, carbon deposits etc., when used as a fuel in an engine. These problems are due to high viscosity, low volatility and polyunsaturated character of vegetable oils. Transesterified vegetable oil derivative called “biodiesel” appear to be most convenient way of utilizing vegetable oil as a substitute fuel in diesel engines. In present investigation, rice bran oil (non-edible) was transesterified to methyl ester and reaction conditions for transeterifcation process for rice bran oil were optimized. Various properties like viscosity, density, flash point of the biodiesel thus prepared are comparable to diesel and found to be in acceptable range as per ASTM norms (ASTM D6751). Experimental investigations were carried out on a four stroke, four cylinders, transportation DI diesel engine. Various blends of biodiesel (rice bran methyl ester) and diesel ranging from 5% to 50% ester in the blend were used for performance and emission test in the transport diesel engine and the results are compared with the baseline data obtained using mineral diesel. Detailed engine tests show that biodiesel can be used as partial substitute fuel in existing diesel engines without substantial hardware modification and it significantly lower the emissions of harmful species from diesel engines without jeopardizing the engine performance.