Experimental Investigation on Performance of a Variable Compression Ratio Engine Fueled with Diesel Butanol Blends with Nano Additives

Butanol is an attractive alcohol having closer properties to that of diesel. This experimental study is to investigate the performance of a variable compression ratio engine fueled with diesel butanol blends enhanced by two nano additives (nano alumina and nano zinc oxide) in various proportions. To start with a solubility test was conducted with various proportions of diesel and butanol (0% to 50%). Optimal blend as (50% diesel and 50% butanol) from diesel butanol blends was selected from this step. Nano zinc oxide (100 - 500ppm) and nano alumina (0 - 100ppm) were blended with this optimal blend through ultasonication. This blend was tested for essential properties such as cetane number, energy content, kinematic viscosity, oxygen content, the heat of vaporization and flash point. Out of the 10 proportions of diesel butanol blends with nano-additives, two blends were chosen with respect to the properties in comparison to that of diesel. These two blends were tested in a variable compression ratio engine by varying compression ratios (16: 1, 17.5:1, 19:1 & 20.5:1) under various load conditions. Results indicated that the compression ratio 19:1 was found suitable for these two blends. Brake thermal efficiency, peak in-cylinder pressure, peak heat release rate, ignition delay, emissions of oxides of nitrogen and smoke produced by these blends at 19:1 compression ratio was found closer to that of diesel. However, the emissions of hydrocarbons and carbon monoxide produced by these blends operated under 19:1 compression ratio was found slightly higher compared to that of diesel.