Application of response surface approach to optimize CI engine parameters fuelled by newly developed waste cooking biodiesel infused with Al₂O₃ nanoparticle

In the present study, newly developed waste cooking biodiesel (B20) with nanoparticles (Al2O3) was tested to optimize the response of a CRDI single-cylinder four-stroke VCR engine at various input parameters. A response surface methodology (RSM) was used to investigate the impact of various input parameters, such as injection pressure (IP), load, compression ratio (CR), and nanoparticle concentration as fuel additives on engine responses, including brake thermal efficiency (BTE), specific fuel consumption (SFC), carbon dioxide (CO), hydrocarbon (HC), and oxide of nitrogen (NOX) emissions. The RSM found the best suitable value of all input parameters at which the engine produced maximum performance and minimum emissions. Accordingly, the optimal setting of all input parameters was identified as a nano biofuel blend ratio of 1.10, IP of 656 bar, CR of 18.50, and a load of 7.10 kg. At this combination of input parameters, the optimal BTE, SFC, CO, HC, and NOx are 23.6%, 0.3461 kg/kWh, 0.0281%, 25.3756 ppm, and 536.41 ppm respectively. The predicted optimum value from RSM is compared with the experimental value for validity and found a fair agreement.