Influence of Ethanol Addition on a Diesel Engine Fuelled with Neem Oil Methyl Ester

An experimental investigation has been carried out to evaluate the effect of using ethanol as additive to neem oil methyl ester on the combustion, performance, and emission characteristics of a diesel engine at different loads and constant engine speed. From the combustion analysis, it is found that the ignition delay increased with higher proportion of ethanol in the blends; maximum cylinder pressure and maximum rate of heat release increased with the increase of ethanol proportion in the blends. From the emission analysis, it is found that at higher engine loads, CO and smoke emissions are found significantly lower when operating on biodiesel–ethanol blends, but HC emissions are found higher. The NOx emissions initially increase with the addition of ethanol in the blends and then decrease with further addition of ethanol.