Comparative analysis of engine performance and emission characteristics of different biodiesels

The paper presents a comparative investigation of the engine performance and emission characteristics of different biodiesel blends and diesel. Castor, linseed, mahua and neem biodiesels were derived through transesterification, and experiments on the performance and emission characteristics were conducted on a constant speed (1500 rpm), four-stroke, variable compression ratio compression ignition engine fuelled with biodiesel blends (B10, B20, B30 and B50) at full load. Experimental results showed that the increasing compression ratio increased brake power and decreased brake specific fuel consumption (BSFC). On the other hand, increasing percentage of biodiesel blends decreased the brake power and increased the BSFC. Neem biodiesel yields higher brake power and lower BSFC than mahua, castor and linseed, and its performance was found to be comparable to that of diesel. Carbon monoxide (CO) emission was found to decrease by 25.37% for diesel, and by 30.71, 31.85, 30.38 and 27.73% for castor, linseed, mahua and neem biodiesel blends, respectively, with increasing compression ratio from 15 to 18, and it increased with increasing percentage of biodiesel blends. Contrarily, the formation of oxides of nitrogen (NOx) increased by 14.06% for diesel, and by 27.39, 23.15, 23.23 and 21.11% for castor, linseed, mahua and neem biodiesel blends, respectively.