ABSTRACT
The use of oxygenated fuels like biodiesel, ethanol can reduce the emissions from the diesel engine. Though Biodiesel has properties similar to diesel fuels, ethanol has more potential to reduce exhause emissions. Ethanol can be manufactured form a number of natural resources but it not soluble in the diesel fuel. Bio-diesels are reported to act as co solvent for diesel-ethanol blends. Therefore, the blends of Diesel-Ethanol-Biodiesel are the promising fuels for the diesel engines because the ethanol and biodiesel overcome each others drawback. The present work consists of experimental investigations of Diesel, anhydrous Ethanol and Jatropha oil derived Biodiesel blends on a four cylinder, naturally aspirated IDI diesel engine. The performance, emission and combustion characteristics are measured at 1200 RPM and various loads for the blends of Diesel-Ethanol-Biodiesel. The results are compared with diesel fuel performance as a baseline. The results obtained for BTE and BSFC are corrected to standard atmospheric conditions i.e. 298K temperature, 100kPa pressure and 30% relative humidity. The results show that for the blends the density is not affected significantly, viscosity is reduced slightly at the higher percentage of ethanol. The maximum reduction in calorific value is of 16% for the blend D. The flash point and the pour points are reduced. A 50% replacement of diesel with 30% ethanol and 20% biodiesel (on volume basis) increased the oxygen content to 12.53% by weight. The brake thermal efficiency is increased but the brake specific fuel consumption is increased by 14% for the blend D. The smoke is reduced remarkably by 35% but there is increase in the NO emissions by 32% for the blend B and C. The carbon monoxide emissions are reduced and the hydrocarbon emissions are very less and unaffected. The peak pressure and the ignition delay are found to be increased at higher loads for the blends.
Keywords: Ethanol, Biodiesel, Diesel-Ethanol-biodiesel blends, Multicylinder, IDI Diesel engine, Smoke.
