Effect of Diesel-Ethanol Blends on Performance, Combustion and Exhaust Emission of a Diesel Engine

Abstract

In this study, the investigations were made on engine performance, combustion and exhaust emission characteristics of a single cylinder four stroke diesel engine using ethanol blended in different ratios with diesel fuel. The test was performed with five different blends of ethanol (E0-neat diesel, E10, E20, E30, E40 and E50).To satisfy homogeneity and prevent phase separation, 3% of Ethyl acetate has been added to ethanol diesel blend. The result of engine test showed that the addition of ethanol caused an increase in the performance which includes improved Brake thermal efficiency by 8% for 10% Ethanol addition and only 2% increase on further Ethanol addition with an added advantage of reduced Specific fuel consumption and the increase of ethanol, ignition\retards and combustion duration shorten, which results in rapid combustion. Ethanol heat release rate increases with increasing ethanol concentration. Considering emissions, CO, HC and Smoke are increased at lower loads but reduced at higher loads as ethanol which is an oxygenated fuel provides free oxygen to assist combustion. The NOx is reduced by 8% with 10% of ethanol blend.