Corn and Rice Bran Biodiesel Blend as Alternative Fuels for Diesel Engine at Different Injection Pressures

Abstract

Experimental study has been carried out using methyl esters of corn oil and rice branoilas fuel blendat the most recommended blending ratio of 20% biodiesel with conventional diesel fuel as alternative fuel for diesel engine.The effect of fuel injection pressure on diesel engine performance using B20 blend in comparison with that using neat diesel fuel is studied. Preliminary experiments regarding the analysis of fuel properties indicate that oils are heated up to the temperature of 50–60°C during process of transesterification. This is necessary to reduce high viscosity of oils as compared with that of neat diesel fuel. A series of tests were conducted on four-stroke single cylinder air cooled direct injection (DI) diesel engine at constant engine speed with varying load in percentage such as 0,25,50,75 and 100 and varying injection pressures of 180, 200 and 200 bar respectively. The investigating parameters include the engine performance parameters such as brake thermal efficiency, brake specific fuel consumption,combustion and emission parameters. The properties of methyl esters of corn oil and rice bran oil fuel blend affect the fuel injection system and cause an increase in the duration of fuel injection .This may cover more time according to the increase in the amount of injected fuel necessary to overcome the power loss accompanied with the biodiesel low energy content. The major conclusion is that, the increased injection pressure gives better results regarding the engine performance parameters in comparison with case of the original injection pressure for all tested fuels, thus the best results are obtained at high injection pressure of 200 bar. At this conditions it is concluded that, the increase of engine BTE and the decrease of BSFC was observed.The emissions like UBHC, CO are comparatively lower for biodiesel blend of B20 compared with diesel fuel. The heat release rate ( HRR) and peak pressure (P-θ) are higher for both tested fuels. This is due to better combustion of fuel due to presence of oxygen in biodiesel. But NOx and smoke opacity are marginally higher than that of the diesel fuel.