An experimental investigation of performance and emission characteristics of diesel engine with blends of cottonseed oil methyl ester with cold and hot EGR

An experimental investigation of diesel engine using cottonseed oil biodiesel and its blends with exhaust gas recirculation (EGR) techniques has been carried out. An optimum nozzle opening pressure of 250 bar and lower static injection timing of 20 degrees before top dead centre (bTDC) are considered because it has been observed that these conditions only give minimum emissions. From the test results, it could be noted that there is an increasing trend of emission characteristics of HC, smoke density and NOx for both cold and hot EGR for all blends of fuel with respect to brake power. As compared with cold EGR, the hot EGR gives lower emissions at all loads. In hot EGR, among the blends, at no-load and full-load conditions, the B100 gives the highest reduction in NOx of 14.23% and 7.91%, respectively. However, the use of EGR leads to a rise in soot emission because of soot-NOx trade-off for both the cases.