Effects of Jatropha biodiesel on the performance, emissions, and combustion of a converted common-rail diesel engine

Abstract

An experimental investigation into the effects of Jatropha biodiesel fuels on the engine performance, emissions, and combustion characteristics of a single-cylinder high-pressure common-rail diesel engine was performed under six different load operations (0.1, 0.2, 0.3, 0.4, 0.5, and 0.6 MPa). The test fuels included a conventional diesel fuel and three different blends of Jatropha biodiesel fuel (JB10, JB30, and JB50). The results revealed that the biodiesel blended fuels had a significant influence on the brake specific fuel consumption (BSFC) at all of the engine load conditions examined. In general, the use of Jatropha biodiesel blends resulted in a reduction in brake specific nitrogen oxide (BSNO_x), brake specific carbon monoxide (BSCO), and smoke emissions, regardless of the load conditions. A large reduction of 20.2% in BSNO_x emissions and 69.5% in smoke opacity were found for the engine when it was fuelled with the biodiesel blends. In terms of the engine combustion characteristics, a slightly shorter ignition delay (ID) and faster combustion duration were found to occur with the use of biodiesel blends under all loading operations. It was revealed that the peak apparent heat release rate (AHRR) for biodiesel blends is lower during low load operation; the AHRR was found to be comparable to that of baseline diesel during high-load operation. Finally, the vibration results demonstrated that the largest reduction, 11.3%, in the root mean square (RMS) of acceleration in comparison with the baseline diesel was obtained with JB50 at an engine load of 0.5 MPa.