Alcohol (Ethanol and Diethyl Ethyl Ether)-Diesel Blended Fuels for Diesel Engine Applications-A Feasible Solution

Abstract

The objective of improving the combustion, reducing the pollutants and to enhance the performance of diesel engines have intensified research in diesel engines. The goal of this study was to percept the combustion, performance and emission characteristics of diesel engine using oxygenated fuels (blending agents). In view of this, experimental investigations were carried out on a single cylinder four stroke direct injection water cooled diesel engine using ethanol and diethyl ether blended fuels in different volume ratios with diesel fuel. The experimental investigation was performed with four different blends of ethanol (E0 -neat diesel, E5, E10, E15 and E20)and diethyl ether (DEE0 - neat diesel, DEE5,DEE10, DEE15 and DEE20) to assess the impact of using ethanol and diethyl ether-diesel blends on diesel engine performance, combustion and emissions. In addition, 2% Ethyl acetate has been added to ethanol diesel blend to retain homogeneity and prevent the interfacial tension between two liquids. For the same rated speed and compression ratio, different blended fuels as well as pure diesel, various engine parameters such as brake thermal efficiency and fuel consumption, combustion parameters such as peak cylinder pressure and exhaust emissions such as smoke opacity, hydrocarbon, CO, and NOx, were measured. The results indicate that the brake thermal efficiency increased with an increase in ethanol and DEE contents in the blended fuels at overall operating conditions. At higher loads, reduced CO emission levels were observed for blends of ethanol and DEE at high load. HC emissions increased for all blends of ethanol and DEE compared with diesel fuel due to high fuel consumption and high latent heat of vaporization which lowers cylinder temperatures and causes the emission of unburned hydrocarbons at lower load. NOx emission slightly reduced with ethanol and DEE blends compared to diesel at lower loads. Further, due to lower calorific value and high latent heat of vaporization of ethanol and DEE results in reduced flame temperature and lower NOx emissions. The NOx emission is almost identical compared to diesel at higher engine loads. Ethanol and DEE showed lowest smoke emissions at high engine loads compared to diesel fuel operation.