Biodiesel as an Alternate Fuel in a Diesel Engine with the Cooled Exhaust Gas Recirculation–A Measure to Reduce Harmful Emissions

Biodiesels reduce the emissions like HC, CO and particulate matter to minimum possible extent. But the NOx emissions increase because of the reason that the biodiesel is an oxygenated fuel. To contain this particular emission which is responsible for the human health degradation, acid rain, smog creation etc., the Exhaust Gas Recirculation (EGR) technique is resorted to. In this paper, a laboratory based DI diesel engine is run with neat biodiesel (Jatropha Methyl Ester) and cooled EGR which replaces a part of incoming air during suction. Various percentages (viz.0%, 7%, and 14%) of EGR were practiced to investigate the effect on the engine performance and tail pipe emissions. EGR dilutes the charge in the cylinder and thus reduces the peak combustion temperatures. Lower combustion temperatures decrease the formation of NOx with the marginal penalty of increase in other emissions. A comparison was made with the implementation of neat diesel and EGR application to consolidate the performance differences emerge in these cases. 7% EGR is proved to be the best percentage by considering both engine performance and emissions