Comparative investigation of emissions and combustion characteristics between ethanol-biodiesel-diesel blends and diesel fuel in a passenger car diesel engine

This study investigated the comparison of emissions and performance characteristics between ethanol-biodiesel-diesel blends and diesel fuel in a passenger car diesel engine. In order to analyse the effect of ethanol-biodiesel blends, the combustion and emission reduction characteristics of a four-cylinder diesel engine with common-rail direct injection system were investigated under the various injection and blended ratios. The experimental results showed that the combustion pressure of ethanol-biodiesel-diesel blended fuels slightly increased than that of convention diesel fuel at higher load condition, while the coefficient of variance of the combustion pressure (COVimep) showed almost the similar values. Under low-load conditions, the effects of ethanol-biodiesel blending to conventional diesel fuel on exhaust emissions showed that brake specific CO emission (BS-CO) and BS-HC emissions remarkably increased while BS-NOx emissions decreased as ethanol blending ratio increased. Under high load conditions, BS-CO, BS-HC and BS-NOx emissions slightly increased as ethanol blending ratio increased. On the other hand, the BS-Soot emissions were reduced by more than 50% in all conditions.