Investigation on Performance and Exhaust Emissions Characteristics of a DI Diesel Engine Fueled with Karanja Methyl Ester and Biogas in Dual Fuel Mode

The present study was aimed to run the diesel engine only with two renewable fuels in a dual fuel mode. The karanja methyl ester (KME) derived from karanja oil was used as an injected fuel, and the biogas obtained from the anaerobic digestion of pongamia pinnata (Karanja) de-oiled cakes, was used as a secondary fuel in a single cylinder, four stroke, air cooled, direct injection (DI) diesel engine. Four different flow rates of biogas, viz., 0.3 kg/h, 0.6 kg/h, 0.9 kg/h and 1.2 kg/h were inducted along with the air in the suction of the engine. The results of the experiment were compared with those of diesel and KME operations. Biogas inducted at a flow rate of 0.9 kg/h was found to be the best among all the flow rates, in terms of the performance and emission of the engine. The dual fuel operation showed a higher BSEC than that of diesel operation at full load. In dual fuel operation, about 22% of KME replacement was possible with the biogas flow rate of 0.9 kg/h at full load. The CO and HC emissions were found to be higher by about 18% and 16% with the biogas flow rate of 0.9 kg/h in comparison with diesel at full load. The NO emission was found to be lower by about 26% for the biogas flow rate of 0.9 kg/h, in comparison with diesel at full load. The biogas flow rate of 0.9 kg/h gave 24.79% reduction in the smoke emission, than that of diesel operation at full load.