Evaluation of ethanol and isopropanol as additives with diesel fuel in a CRDI diesel engine

In this study, alcohol fuels such as ethanol and isopropanol were used as additives with diesel fuel and two blends (15% ethanol-85% diesel fuel, and 15% isopropanol-85% diesel fuel) were prepared. Detailed and comparative performance, combustion, injection, and emission analysis of these blends and pure diesel fuel were performed in a common rail direct injection (CRDI) diesel engine. The test engine was operated under three engine speeds (1500, 2000 and 2500 rpm) and four engine loads (BMEP: 3.3, 5.0, 6.6 and 8.3 Bar) test conditions. According to the experimental results, alcohol fuel blends with diesel fuel caused higher brake specific fuel consumption (BSFC) values. Maximum cylinder pressure (MCP) values of the fuel blends were slightly higher than those of pure diesel fuel on average. The pilot and main injection characteristics of the CRDI fuel system showed different trends with respect to the engine load and speed. Outcomes of emission tests revealed that the CRDI diesel engine fueled with alcohol-diesel fuel blends emitted higher THC, CO and NOx emissions compared to neat diesel fuel. Alcohol fuel blends did not significantly affect CO2 emissions. Ethanol-diesel and isopropanol-diesel fuel blends had similar combustion and emission results to each other.