Abstract:
In this study, a direct injection compression ignition (DICI) engine was modified to utilize croton esters-diesel blends in equal ratios and at varied fuel injection pressures. The main aim of this research is to make use of alternative fuels for diesel engines and to reduce the emission of exhaust gases while minimizing the reduction of brake thermal efficiency associated with the low calorific value of bio-fuel. The engine was tested at varied injection pressures of 220, 240, 260 and 280 bars and at 0%, 10%, 20% and 30%exhaust gas recirculation (EGR) and the performance and emission characteristics of the modified engine were analyzed. The effect of higher injection pressures than the engine’s standard value of 220 bars and the varied EGR percentages on performance parameters of brake thermal efficiency (BTE), brake specific fuel consumption (BSFC) and exhaust gas temperature (EGT) were studied. The effect of blending croton oil esters in diesel on emissions of smoke, carbon monoxide (CO), hydrocarbon (HC) and carbon dioxide (CO2) is also presented and analyzed. The performance and emission characteristics were compared among the different injection pressures and exhaust recirculated gas percentages and the results show that brake thermal efficiency increased up to 240 bars before decreasing while the brake specific fuel consumption decreased and then increased at this injection pressure. Exhaust gas recirculation lowered the brake thermal efficiency except for 280 bars where 20% EGR enhanced the engine’s efficiency. Higher injection pressures decreased the emission of the exhaust gases and exhaust gas temperatures.
