Study of performance and emission characteristics of twin cylinder off road diesel engine using soapnut oil methyl ester and diesel blends

An experimental study has been carried out to study the performance of an agricultural tractor engine using the blends of soapnut oil methyl ester and diesel. The results were compared with conventional diesel fuel. The exhaust gas emission especially NOx and Particulate Matter of agricultural engine are very high compared to on road vehicle engines. But the efforts taken to cut down emissions from these off-road engines are still very less. One such effort is to use the blends of a low viscous fuel with a high viscous non-edible oil. Soapnuts were collected from local stores, cleaned and dried for 5 to 6 days in sunlight, the kernels were cold pressed to extract oil. The purified oil was trans-esterified with the presence of methanol and KOH as catalyst to remove the fatty acids and glycerol. The methyl esters of soapnut oil was blended with diesel at different proportions. The blends SNB10, SNB20 and SNB30 were prepared on volume basis and the prepared blends were compiled ASTM D-6751 specifications. The experiments were conducted in a Simpson S217, twin cylinder tractor diesel engine to study the performance and emission characteristics of soapnut methyl esters blended with diesel. The experimental results showed that the biofuel blends outperformed conventional diesel fuel in terms of particulate matter (PM), carbon monoxide (CO), carbon dioxide (CO2), and hydrocarbon (HC) emissions, with slight penalty on NOx emissions.