Abstract:
Karanja (Pongamia pinnata) oil, a non-edible high viscosity (27.84 cSt at 40 C) straight vegetable oil, was
blended with conventional diesel in various proportions to evaluate the performance and emission characteristics
of a single cylinder direct injection constant speed diesel engine. Diesel and karanja oil fuel
blends (5%, 10%, 15%, and 20%) were used to conduct short-term engine performance and emission tests
at varying loads (0%, 20%, 40%, 60%, 80%, and 100%). Tests were carried out over the entire range of engine
operation and engine performance parameters such as fuel consumption, thermal efficiency, exhaust gas
temperature, and exhaust emissions (smoke, CO, CO2, HC, NOx, and O2) were recorded. The brake specific
energy consumption (BSEC), brake thermal efficiency (BTE), and exhaust emissions were evaluated to
determine the optimum fuel blend. Higher BSEC was observed at full load for neat petro-diesel. A fuel
blend of 10% karanja oil (KVO10) showed higher BTE at a 60% load. Similarly, the overall emission characteristics
were found to be best for the case of KVO10 over the entire range of engine operation.
