Influence of Exhaust Gas Recirculation on Performance, Combustion, and Emission Characteristics of a Common Rail Direct Injection Diesel Engine Fueled by Diesel/Higher Alcohol Blends

Emission and combustion parameters of common rail direct injection combustion engine with different proportions of exhaust gas recirculation (EGR) rate and long-carbon-chain alcohol blends on performance are the main motive of this research. To lessen the dependency on diesel fuel and reduce harmful emissions, 1-hexanol is used, as it has better fuel properties than small-carbon-chain alcohol, and it can be blended with diesel. In common rail direct injection combustion engine, research was conducted, in which fuel blends (1-hexanol-diesel) were variant, i.e., (10%, 20%, 30%) by volume whereas engine speed was fixed at 1500 rpm by varying the load at 25% step from 25 to 100%. Blends were examined with various exhaust gas recirculation rates (10 and 20%) to see what impact they have on engine properties. It was observed that the higher the proportion of 1-Hexanol, the lower the engine performance. The research revealed that for the blend D70H30, around 8.24% rise in brake specific fuel consumption, slight rise in hydrocarbon, 2.80% reduction in brake thermal efficiency (BTE), and 16.70% reduction in nitrogen oxides (NO_x) emission. With 1-hexanol-diesel blends, the engine is noted to function effortlessly, so as a substitute to the diesel upto 30% of the 1-hexanol can be used while increasing the total cost of implementation. Increase in hexanol and EGR percentage shown negative impact on the brake thermal efficiency, HC and CO emission however, NO_x and CO₂ emissions were found to be decreased.