Combustion, performance and emission characteristics of various alcohol blends in a single cylinder diesel engine

In this study, the influence of the various alcohol additions in diesel fuel on combustion, performance, and exhaust emission characteristics of a single-cylinder diesel engine was investigated at different loads. The alcohol blends obtained by mixing 10% of butanol, ethanol, and methanol with diesel fuel (called B10, E10 and M10 respectively) and petroleum-based diesel fuel (D100) were used in the experiments. The results showed that the ignition delay of the alcohol blends is longer than D100 due to the low cetane number of the alcohol fuels. Their peak cylinder pressures are higher compared to the diesel fuel for all engine loads. In addition, the maximum heat release rates of the alcohol blends are higher than diesel fuel due to the longer ignition delay and excessive oxygen content of alcohols. D100 has the lowest brake specific fuel consumption and the highest brake thermal efficiency compared to alcohol blends for all engine loads because of the higher heating value. B10, E10, and M10 follow D100 respectively in accordance with the heating values of the fuels. Also, alcohol addition causes a slight increase in nitrogen oxides (NOx) emissions while causing a reduction in smoke and carbon monoxide (CO) emissions.