Optimization of diesel engine performance and emission characteristics with cerium oxide nanoparticles mixed waste cooking oil biodiesel blends

The study investigates the performance and emission characteristics of a four-stroke, single-cylinder, and direct injection diesel engine with variable compression ratio using nanoparticles blended biofuel. The cerium Oxide (CeO2) nanoparticles have been blended in corresponding ratios with waste cooking oil (WCO) biodiesel. Further, response surface methodology (RSM) based Box-Behnken design (BBD) approach was used to evaluate engine performance parameters such as brake specific fuel consumption (BSFC), brake thermal efficiency (BTE), and emission characteristics (such as NOx, CO, and CO2 emission). In addition, the quadratic models were obtained to investigate the influence of input parameters on each output response with analysis of variance (ANOVA). The desirability approach was used to obtain the optimal engine performance and emission characteristics. The analysis revealed that WCO blended with CeO2 nanoparticles fuel improves CI engines' performance and reduces their hazardous emissions. The compression ratio of 14:1 at 10.29% blend composition and 50 ppm concentration level of nanoparticles with composite desirability of 0.858 was found to be the engine's optimal operating conditions. At optimal conditions, BTE, BSFC, NOx, CO, and CO2 were 36.62%, 0.2204 kg/kW-h, 168 ppm, 0.0192%, and 1.132% respectively.