Effect of Ni and Al nanoadditives on the performance and emission characteristics of a diesel engine fueled with diesel-castor oil biodiesel-n-butanol blends

Biodiesel has emerged as a viable renewable fuel with the potential to reduce reliance on fossil fuels and partially replace petroleum-based fuels. Moreover, using biodiesel reduces pollutant emissions. However, utilizing biodiesel results in inferior engine performance along with elevated NOx emissions. There is a scope to address these concerns by employing n-butanol and metallic nanoparticles (NPs) as fuel additives. In this study, castor oil biodiesel is blended with 100 ppm Ni and Al NPs and diesel along with n-butanol forming various stable fuel blends such as D100, D90B10, D80B10Bu10, D90B10+Ni, D80B10Bu10+Ni, D90B10+Al, and D80B10Bu10+Al to investigate their effect on engine performance and emission. The use of n-butanol substantially diminishes engine performance. However, the inclusion of Ni and Al NPs with D90B10 increases torque by 2.33% and 2.04%, increases BP by 2.33% and 2.04%, decreases BFSC by 8.96% and 6.13%, and increases BTE by 8.87% and 5.43%, respectively. Moreover, the addition of Ni and Al NPs to D80B10Bu10 increases torque by 14.99% and 8.09%, increases BP by 14.99% and 8.09%, decreases BFSC by 5.06% and 7.68%, and increases BTE by 3.81% and 6.49%, respectively. The use of n-butanol with a biodiesel blend drastically lowers CO and NOx emissions. The inclusion of Ni and Al nanoadditive further reduces CO and NOx emissions. The addition of Ni and Al NPs to D90B10 decreases CO emission by 12.07% and 14.66% and decreases NOx emission by 4.27% and 9.82%, respectively. In addition, the inclusion of Ni and Al NPs with D80B10Bu10 decreases CO emission by 16.43% and 13.15% and decreases NOx emission by 3.98% and 10.75%, respectively.