Combined effect of oxygenated liquid and metal oxide nanoparticle fuel additives on the combustion characteristics of a biodiesel engine operated with higher blend percentages

In this study, an attempt has been made to investigate the use of higher blend percentage of biodiesel in diesel engines without affecting much on the performance of engines using fuel additives. Waste cooking oil (WCO) biodiesel B30 blend (WCO 30% + neat diesel 70%) and B40 (WCO 40% + neat diesel 70%) are used as the fuel together with diethyl ether and Cerium oxide (CeO₂) nanoparticles as additives. Biodiesel is mixed with 2% by volume of diethyl ether (DEE) and 80 ppm concentration of CeO₂ nanoparticles which are maintained constant throughout the study. Performance, combustion characteristics and emission parameters have been studied and compared with the values for neat B30 and B40 biodiesel. Results showed that brake thermal efficiency of B30 with additives is 29.57% and is at par with neat B20 operation (29.72%). Maximum reduction of HC and smoke emissions are observed for B40 with additives, which are 16% and 11.7% less than neat B20 fuel operation. B30 with diethyl ether and CeO₂ nanoparticles showed minimum NOx emission which is 6% less than neat B20.