The effects of ethylhexyl nitrate on the performance of diesel engine fueled with diesel and gasoline blends: From engine bench test to vehicle driving cycle test

The improvement of cetane number of gasoline diesel blend fuel (GDBF) with the addition of 2-ethylhexyl nitrate (EHN) is rarely mentioned or quantified in the reported studies. In this work, combustion and emission characteristics of GDBF with 50 % gasoline (G50) with 1‰–3‰ EHN addition were compared on a single cylinder compression ignition engine. Then New European Driving Cycle driving cycle test was conducted on a commercial SUV equipped with the same 4-cylinder engines running with diesel and G50 with 3 ‰ EHN. The results show that with EHN addition, ignition delay of G50 were shortened and the coefficient of variation were reduced, indicating the improved combustion stability. Adding 3 ‰ EHN, the total hydrocarbon (THC) and carbon monoxide (CO) emissions of G50 were reduced by up to 85 %, and 50 %, respectively, while nitric oxide (NOx) was increased slightly. The cetane number of G50 added by 1 ‰, 2 ‰, and 3 ‰ EHN were 40.83, 44.25 and 45.8, respectively. The driving cycle test shows that the vehicle can run smoothly and well catch the speed demand of the driving cycle. Compared with diesel, G50E3 exhibits lower the exhaust absorption coefficient and fuel consumption with higher but comparable emission factors of CO, THC and NOx.