Evaluating The Impact Of EGR On Butanol-Diesel Blends In A CRDI Engine: Performance And Emission Analysis

The study evaluates the performance and emission characteristics of a single-cylinder CRDI research engine using Pure Diesel (PD) and butanol-diesel blends (B10, B20, and B30) under varying Exhaust Gas Recirculation (EGR) rates (0%, 10%, 20%, and 30%). Among the tested fuels, B20 exhibits the most balanced performance, achieving a favorable Brake Thermal Efficiency (BTE) while maintaining manageable emission levels. Although BTE generally decreases with higher butanol content due to its lower calorific value, B20 shows a moderate increase in Brake Specific Fuel Consumption (BSFC) compared to pure diesel, with less of a trade-off in efficiency than B30. Emission results indicate that HC and CO emissions increase with rising EGR rates and higher butanol percentages, but B20 maintains lower emissions compared to B30 across all EGR levels. Additionally, B20 effectively reduces NOx emissions due to the cooling effect of butanol and controlled combustion temperatures, particularly at higher EGR rates. Overall, B20 strikes an optimal balance between performance and emissions, demonstrating its potential as a viable alternative fuel blend for enhancing engine efficiency while minimizing environmental impact.