Experimental investigation on performance, emission and combustion characteristics of croton megalocarpus biodiesel blends in a direct injection diesel engine

Abstract

The emission, performance and combustion characteristics of croton biodiesel blends were tested in a direct injection (DI) single cylinder four stroke diesel engine. The physico-chemical properties of the biodiesel blends were all found to be within the standard ASTM values. The reduction in exhaust smoke emissions for the biodiesel blends ranged from 10% to 41% at maximum engine load of 10 Kg while a slight increase in NOx emissions was observed with increase in concentration of biodiesel in the blends. Similar general increase in brake thermal efficiency (BTE), temperature of exhaust emissions and fuel flow rate was observed with increasing engine load for both petro-diesel and biodiesel blends. The difference between BTE for petro-diesel and biodiesel blends ranged from 2.04 to 5.03%. The brake specific energy consumption (BSEC) decreased with increasing engine load for both petro-diesel and biodiesel blends. An increase in both engine pressure and heat released was observed with increase in concentration of biodiesel in the blends. The difference in maximum engine pressure ranged from 1.05 bar at 0 Kg to 3.77 bar at 10 Kg load. The greatest difference in maximum engine pressure was recorded between petro-diesel and B50 blend. The observed difference in position of peaks for maximum heat released showed that there was slight delay in ignition of biodiesel blends as compared to petro-diesel. The results obtained in this study showed that higher blends of up to 50% biodiesel can be effectively used as an alternative to petro-diesel without compromising the engine performance.