THE SPRAY AND ENGINE COMBUSTION PERFORMANCE OF ETHANOL-BIODIESEL FUEL BLENDS

Some research has studied the effects of ethanol blended diesel (E-diesel) on emissions due to the availability of ethanol. However, a co-solvent or emulsifier is needed to provide better mixing of these two fuels, which would complicate the production process. In recent years, researchers have reported that biodiesel is a good co-solvent in terms of its miscibility with ethanol. Therefore, the present study utilizes the name "E-Biodiesel" representing the blend of ethanol and biodiesel as an alternative fuel. In this paper, the effects of blending ratios (B100, B80E20, and B60E40) of ethanol-biodiesel on viscosity, spray vaporization, engine combustion, and exhaust emissions are investigated. The viscosity measurements show that appropriate ethanol-biodiesel blends could approach the viscosity of ultra-low sulfur diesel (ULSD). The effect of blends on fuel spray structure is investigated by using two single-hole injectors with different nozzle orifice diameters (80 mu m and 150 mu m) and high-speed Schlieren imaging. The results indicate that different patterns of spray vaporization are observed due to the addition of ethanol at different ambient pressure. The combustion and emission tests are carried out in a multi-cylinder high-speed diesel engine, and the effects of E-Biodiesel are significant with respect to the power output, fuel consumption, and emissions. As a result, nitrogen oxides (NOx) and particulate matter (PM) could be reduced simultaneously by the adjustment of injection timing and exhaust gas recirculation (EGR). Therefore, with proper blending ratios of biodiesel and ethanol, E-biodiesel could be considered viable as an alternative fuel in the future.