Investigation on the Combustion and Emission Characteristics in a Diesel Engine Fueled with Diesel-Ethanol Blends

The aim of this work is to investigate the effects of different diesel–bioethanol blended fuels on combustion, engine performance, and emission characteristics in a four-cylinder common rail direct injection (CRDI) diesel engine according to various engine loads. Combustion characteristics including in-cylinder pressure, maximum in-cylinder pressure, heat release rate (HRR), and maximum HRR; engine performance including brake specific fuel consumption (BSFC); and emission characteristics including carbon monoxide (CO), hydrocarbon (HC), nitrogen oxides (NOx), and smoke were compared and analyzed. The four test fuels were diesel (D100), 95% D100 blended with 5% ethanol by volume (D95E5), 90% D100 blended with 10% ethanol by volume (D90E10), and 85% D100 blended with 15% ethanol by volume (D85E15). The results indicated that the addition of ethanol had no great impact on the in-cylinder pressure and HRR, but it could significantly reduce CO, NOx, and smoke emissions. The only deficiency was that BSFC was increased to varying degrees with increase of ethanol due to its low heating value.