Combustion, performance, and emissions of a compression ignition engine using Pongamia biodiesel and bioethanol

Concerns over the depletion of conventional fuels have increased interest in new renewable energy sources like alcohol- and vegetable-based oils. Major drawbacks of using esters of vegetable oils, known as biodiesel, include reduced engine performance and increased emissions of oxides of nitrogen. In the present study, the effects of ethanol on biodiesel and mineral diesel blends in a diesel engine are experimentally investigated. The ethanol is produced from cashew apple juice by fermentation. Experiments are conducted using B20 Pongamia biodiesel with ethanol in proportions of 5, 7.5, and 10% by volume at varying load conditions. The results indicate that a B20 biodiesel blend with 7.5% ethanol yields a higher brake thermal efficiency and lower brake-specific energy consumption than pure B20 (20% biodiesel + 80% diesel), as well as significantly reduced emissions such as oxides of nitrogen, carbon monoxide, hydrocarbons, and smoke.