Response surface methodology-based optimization of the amount of cerium dioxide (CeO2) to increase the performance and reduce emissions of a diesel engine fueled by cerium dioxide/diesel blends

Abstract

The supplement of metal nanoparticles to diesel fuel in specific amounts has been included as an innovative approach to the studies on reducing pollutant emissions of compression ignition engines. In present research, the impacts of adding cerium dioxide (CeO2) nanoparticles, which is a highly oxidizing and reactive additive, to diesel fuel in different amounts (25, 50, 75, and 100 ppm) were experimentally investigated at different engine loads (8, 12, 16, 20, and 25 Nm) and optimized using the response surface methodology (RSM). According to the experimental results, the supplement of CeO2 decreased the brake-specific fuel consumption (BSFC) and enhanced the brake-thermal efficiency (BTHE) and exhaust gas temperature (EGT). On the other hand, the addition of CeO2 caused a decrease in hydrocarbon (HC), carbon monoxide (CO), and smoke emissions, and on the contrary, an increase in nitrogen oxide (NOx) emissions. Under the RSM findings, determined the optimal CeO2 quantity and engine load as 100 ppm and 12 Nm, respectively. Optimum responses corresponding to optimal CeO2 and engine load were determined as 23.125%, 429.766 g/kWh, 335.143 °C, 0.257%, 130.898 ppm, 786.309 ppm, and 25.654% for BTHE, BSFC, EGT, CO, HC, NOx, and smoke, respectively. Optimal results were obtained with a high desirability value of 0.7115. A good agreement between the experimental and RSM-predicted response values indicates that the developed RSM design was successful.