Optimisation of an experimental and feasibility research on a CRDI diesel engine based on a blend of waste cooking oil and waste plastic oil using RSM: A value addition for disposed waste oil

This investigation aims to use a combination of waste cooking oil (WCO) and waste plastic oil (WPO) biodiesel blended with diesel in a common rail direct injection (CRDI) diesel engine. This study examined the effects of (WCO + WPO) blend %, fuel injection timing (FIT), exhaust gas recirculation (EGR), and engine load on the performance and emission of diesel engines. The trials were developed using the central composite design (CCD) approach and the accompanying multiple responses were investigated using response surface methodology (RSM). The WCO biodiesel was produced by the transesterification method, with an 88% yield. Based on the combined effects of the uncertainties from the temperature sensor, load sensor, Brake Thermal Efficiency (BTE), Brake Specific Fuel Consumption (BSFC), and Exhaust Gas Temperature (EGT), carbon monoxide (CO), unburned hydrocarbons (HC), and nitrogen oxides (NOx), the percentage of uncertainty was found to be +/- 2.53%. The outcomes of the analysis of variance (ANOVA) revealed that the experimental and estimated outputs were in good agreement. R2 values were determined to be 98.41%, 97.02%, 99.29%, 98.49%, 98.71%, and 98.21% for BTE, EGT, BSFC, HC, CO, and NOx, respectively. The input factors optimised at14% biodiesel, 25obTDC FIT, 6% EGR value, and 35% engine load, for which the best output parameters were discovered to be 20.3%, 485.6 K, 370.9g/kWh, 0.18% vol., 17.8ppmv, and 336.33ppmv for BTE, EGT, BSFC, HC, CO, and NOx, respectively. Validation tests were performed to confirm optimisation findings by setting engine input parameters to optimum levels, which were determined and reported as in an acceptable range.