Improvement of exhaust emissions in a diesel engine with the addition of an oxygenated additive to diesel-biodiesel blends

Emissions control in internal combustion engines is the big challenge faced by engine manufacturers. Modern internal combustion engines exploit various systems to reduce exhaust emissions. However, the existing emission control systems will fall short of meeting stringent future emission regulations. This study attempts to reduce the exhaust emissions of a diesel engine fuelled with diesel-biodiesel blends by utilising ethyl acetate as a renewable oxygenated fuel additive. In this context, initially, ethyl acetate is mixed with biodiesel-diesel blends by 5% and 10% volume to obtain test fuels. Then, their fuel properties are measured by applying test methods proposed in the standards. Subsequently, engine experiments are conducted on a single-cylinder four-stroke diesel engine operated on distinct test conditions. The findings indicate that the inclusion of ethyl acetate in the diesel-biodiesel blends improves the fuel quality and markedly decreases emissions. A substantial reduction is achieved in NOX, soot, and CO emissions up to 50%, 70%, and 71%, respectively, with a slight increase in fuel consumption in the case of adding ethyl acetate. More importantly, the addition of ethyl acetate enhances the NOX-smoke trade-off and NOX-BSFC trade-off characteristic of a diesel engine without loss of thermal efficiency. From this research, it can be inferred that ethyl acetate can potentially reduce exhaust emissions of the existing diesel engines fuelled with diesel-biodiesel blends.