Impact of injection timings and exhaust gas recirculation rates on the characteristics of diesel engine operated with neat tamarind biodiesel

The extensive usage of petroleum products in the power sector, industries, and transportation may lead to the depletion of fossil resources. Also, the most important human challenges of the 21(st) century are global warming and climate changes due to increased pollution levels. Nowadays, the need for new energy sources is one of the foremost problems of all countries in the world. The current experimental work is primarily focusing on the exploration of neat tamarind seed methyl ester (TSME) as a sustainable energy source for diesel engines. All the physicochemical properties were determined experimentally with concern to ASTM standards and compared with diesel fuel. Initially, tests were performed on a diesel engine with diesel and neat tamarind biodiesel in standard operating conditions 23o CA bTDC. Later, the injection timing was varied like 19o CA bTDC and 27o CA bTDC for the neat tamarind biofuel. A test result found with TSME biofuel that enhancement in brake thermal efficiency (BTE) by 4.07% was achieved with the retardation of engine injection timing when compared to standard injection timing. Also, it was found that drastic reduction of exhaust emissions by 9.7%of CO, 15.8% of HC and 6% of SO have resulted in the retarded injection timing of TSME when compared to standard conditions of TSME at full load. However, the oxides of nitrogen emissions were increased. To control the oxides of nitrogen emissions, exhaust gas recirculation (EGR) at two levels such as 10% and 20% were used when the engine was operated at retarded injection timing (IT) with TSME. It was found that TSME with 10% EGR inferred a drastic reduction of nitrogen oxide emissions by 30% and 37.7% over diesel and TSME, respectively, at full load.