Effects of butanol blending and fumigation with Jatropha biodiesel on combustion, performance, and emissions of diesel engine

Abstract

In this study, conventional diesel fuel, pure Jatropha biodiesel, Jatropha-butanol blended fuel, and Jatropha biodiesel with fumigated butanol were tested in a single-cylinder direct-injection four-stroke diesel engine. The engine performance, combustion, and emissions were measured at 3600 rpm and brake power of 4.4 kW. For Jatropha, tests revealed that brake thermal efficiency was reduced by 5% and brake-specific fuel consumption was increased by 17% relative to diesel. An overall reduction in exhaust emissions (oxides of nitrogen, unburned hydrocarbons, and smoke opacity) was observed with the exceptions of carbon monoxide and carbon dioxide. For Jatropha-butanol blended fuel, the efficiency was increased by 2% relative to Jatropha; however, it was still 3% less than that of diesel. The fuel consumption was increased relative to both Jatropha and diesel. In terms of emissions, oxides of nitrogen and smoke opacity were reduced by 12.3% and 72%, respectively, with increased carbon monoxide and unburned hydrocarbon emissions compared to diesel fuel. For Jatropha with fumigated butanol, the efficiency was increased by 4% relative to Jatropha and decreased by mere 1% when compared to diesel. The fuel consumption showed a reduction of 1.4% when compared to Jatropha. A substantial decrease in opacity (85%), oxides of nitrogen (12.7%), and carbon dioxide (4%) emissions was recorded relative to diesel; however, carbon monoxide and unburned hydrocarbons were increased. It was concluded that butanol fumigation successfully improved the properties of Jatropha biodiesel and provided an overall better performance relative to blended fuel and neat Jatropha biodiesel.