Reduction of Environmental Pollution Generated from a Diesel Engine Using Diesel-Ethanol-Water Micro Emulsion

Alcohol is one of the renewable energy sources that can be locally produced as well as serves as a source that would help in considering the depleting natural petroleum fuel resources. However, its non miscibility with diesel, especially at high alcohol ratios, low cetane number and poor lubricating characteristics have restricted its utilization in diesel engines. Usually, when ethanol contents in the blends reach 20-40%, high concentration of additives are needed to ensure the mixture homogeneity in the presence of high water contents, and to attain the required cetane number for suitable ignition. Therefore, selection of suitable additives plays a vital role for increasing the solubility of ethanol to a larger extent. Similarly, selection of a suitable surfactant is very important for obtaining long lasting emulsions. The surfactant span 20 and tween 20 have been selected here on account of their favourable properties and been focused in this study, as they have been used to stabilize the ethanol diesel and water emulsions and as an alternate fuel. A single-cylinder, air-cooled, direct injection diesel engine that could develop a power output of 5.2 kW at 1500 rev/min was used. Engine performance and emission data were used to optimize the blends for reducing emission and improving performance.