NOx reduction in a DI diesel engine using biodiesel as a renewable fuel

Many studies have reported that exhaust from biodiesel fuel has higher oxides of nitrogen, whereas hydrocarbon (HC) and smoke emissions are significantly lower than that of diesel fuel. The performance of biodiesel fuel is comparatively lower in terms of efficiency because of its lower heating value and higher density. In this investigation, ethyl ester of mahua oil was prepared by transesterification using sulphuric acid (H2SO4) as catalyst and tested in a 4-stroke direct injection naturally aspirated diesel engine. The results show that engine exhaust emissions (CO, HC, NOx and smoke) were low when compared with that of diesel fuel without affecting the performance much. From this investigation, it may be concluded that biodiesel having some specific fatty acid composition can reduce NOx emissions.