Rice Bran Oil Biodiesel as an Additive in Diesel- Ethanol Blends for Diesel Engines

A number of studies currently focus on the renewable fuels to reduce the reliance on petroleum fuels. Biofuels such as biodiesel and bioethanol have been studied and tested in many countries including India. One of the methods to reduce the use of fossil fuel is blending ethanol with fossil diesel. However, an emulsifier or a co-solvent is needed to homogenize the diesel-ethanol blends. The rice bran oil biodiesel offers an alternative application as an emulsifier for diesel and ethanol blends. The present research is aimed to investigate experimentally the performance and exhaust emission characteristics of a direct injection (DI) diesel engine when fuelled with conventional diesel fuel, rice bran oil biodiesel, a blend of diesel and rice bran oil biodiesel and three blends of diesel-biodiesel-ethanol over the entire range of load on the engine. The experimental results showed that the highest brake thermal efficiency was observed with 15% ethanol in diesel-biodiesel-ethanol blends. The exhaust gas temperature and the sound intensity from the engine reduced with the increase of ethanol percentage in diesel-biodiesel-ethanol blends. The Carbon monoxide and smoke emissions reduced significantly with higher percentage of ethanol in diesel-biodiesel-ethanol blends. The unused oxygen with 5% ethanol in diesel-biodiesel-ethanol blend was lower than that of diesel fuel. The Hydrocarbons, Oxides of nitrogen and carbon dioxide emissions increased with the increase of ethanol percentage in diesel-biodiesel-ethanol blends but the hydrocarbon emissions were still lower than that of diesel fuel. As the brake thermal efficiency increased and carbon monoxide, sound, hydrocarbons and smoke were lower than that of diesel fuel with the diesel-biodiesel-ethanol blends, the rice bran oil biodiesel can be used as an additive to mix higher percentages of ethanol in diesel-ethanol blends to improve the performance and reduce the emissions of a diesel engine.