PERFORMANCE AND EXHAUST EMISSION CHARACTERISTICS OF A DIESEL ENGINE FUELLED WITH PUNGAMIA METHYL ESTERS AND DIESEL OIL BLENDS

The objective of this study is to compare the engine performance and emission results of biodiesel derived from pungamia oil when applied in different proportions in a stationary diesel engine without any engine modifications. A single cylinder four stroke diesel engine was tested at various loads with the blended fuel at the rated speed of 1500 rpm. Esterified pungamia oil and diesel blends having 10%, 20%, 30%, 40% and 50% Pungamia oil on volume basis and pure diesel were used as fuel. Engine performance with pure diesel was also evaluated for comparison. An AVL 5 gas analyzer and a smoke meter were used for the measurements of exhaust gas emissions. Engine performance (brake specific fuel consumption, brake thermal efficiency, and exhaust gas temperature) and emissions (HC, CO, CO2, NOX and Smoke Opacity) were measured to evaluate and compute the behaviour of the diesel engine running on biodiesel. The results show that the brake thermal efficiency of diesel is higher at all loads followed by blends of Pungamia oil and diesel. Experimentally the maximum brake thermal efficiency and minimum specific fuel consumption were found for a blend having 10% Pungamia oil at all loads among the blends. The specific fuel consumption was found to be even lower than the conventional diesel for blends up to B30. The brake thermal efficiency for B10 and B20 were also closer to diesel and the CO2 and NOX emissions were found to be lesser than diesel while there was a marginal increase in the smoke opacity. The increase in opacity can be effectively managed by engine optimization. The reductions in brake specific fuel consumption and CO2 emissions made the blend of biodiesel B20 a suitable alternative fuel for diesel and thus could help in controlling air pollution.