Emission reductions studies of a biodiesel engine using EGR and SCR for agriculture operations in developing countries

This paper reports the experimental results of a single cylinder diesel engine regarding performance, combustion and emission characteristics using Mahua (Madhucaindica) biodiesel and its blends in different volumetric proportions with petro-diesel. The thermo-physical properties of various blends selected for investigation have been experimentally measured for better evaluation of the performance characteristics. Tests have been carried out on a four stroke tangentially vertical (TV) single cylinder diesel engine at 1500rpm using an eddy current dynamometer. The static injection timing employed is 20° bTDC with constant nozzle opening pressure of 250bar. Selective Catalytic Reduction (SCR) as well as Cold and Hot Exhaust Gas Recirculation (CEGR and HEGR) techniques are employed to study the reduction of NOx. Results are compared at full load under steady state condition with conventional engine where no reduction techniques are applied. The comparison indicates that the SCR gives substantial reduction in oxides of nitrogen (NOx) as compared to other technique in a conventional diesel engine fuelled with biodiesel, B100. For B100 with SCR technique, the percentage reduction in NOx is around 20% as compared to conventional engine. This research has been carried out keeping in mind the energy consumption by pumps coupled to diesel engines for irrigation purpose and locomotive tractors used in developing countries. The research findings show that Mahua biodiesel gives equally good performance and lower emissions which make it a good alternative fuel to operate diesel locomotives as well as irrigation pumps without any engine modification.