An Experimental Investigation on Performance, Combustion and Emission Characteristics of Diesel- Biodiesel Blends with Isobutanol as an Additive

Biodiesel with fuel additives has been gaining increased attention from engine researchers in view of the energy crisis and increasing environmental problems. The present work is aimed at experimental investigation of Isobutanol as an additive to the diesel-biodiesel blends. Experiments were done on a 4-stroke single-cylinder diesel engine by varying percentage by volume of isobutanol in diesel-biodiesel blends. The effect of isobutanol on brake thermal efficiency, brake specific fuel consumption, cylinder pressure, heat release and exhaust emissions were studied. It was found that brake thermal efficiency increased with increase in blend percentage both with 5% and 10% isobutanol. Addition of isobutanol shows negative impact on brake specific fuel consumption (BSFC) which decreased with blend percentage while it increases with isobutanol percentage. Heat release curves show the similar start for diesel and blends. Cylinder pressure decreases slightly with increase in isobutanol percentage while heat release increases compared to diesel. CO emissions and smoke opacity decreased significantly while NO_x emissions decreased marginally with the increase in isobutanol percentage.