Comparative analyses of n-butanol-rapeseed oil-diesel blend with biodiesel, diesel and biodiesel-diesel fuels in a turbocharged direct injection diesel engine

The purpose of this work is to understand the effects of a diesel-rapeseed oil-n-butanol (70-20-10% in vol, DRSOnB) blend on engine performance characteristics and exhaust gas emissions for a four-cylinder, four-stroke, turbocharged, direct injection diesel engine as a function of engine speed, and to compare the results to those of rapeseed oil methyl ester (B100), rapeseed oil methyl ester-diesel blend (20-80% in vol, B20) and diesel fuel. Transesterification and microemulsion methods were used to produce rapeseed oil methyl ester and diesel-rapeseed oil-n-butanol blends, respectively. The engine performance and exhaust emission tests were conducted employing each of DRSOnB, B100, B20 and diesel fuel, with the engine operating at full load and eight different engine speeds between 1800 and 4400 rpm. As compared to diesel fuel, the test fuels decreased torque, brake power and exhaust gas temperature and increased brake specific fuel consumption (BSFC). While B20 and DRSOnB blends increased carbon monoxide (CO) emissions, B100 decreased it compared to diesel fuel. All the test fuels reduced hydrocarbon (HC) emissions while increasing nitrogen oxides (NOx) formation.