Effects of Aluminum Oxide and Cerium Oxide Nanoparticles on the Performance and Emission Characteristics of a CI Engine Fueled with Diesel–Jatropha Biodiesel Blends

This study examines the synergistic effect of aluminum oxide (Al₂O₃) and cerium oxide (CeO₂) nanoparticle additives on a CI engine using diesel-Jatropha biodiesel blends. Jatropha biodiesel was produced via transesterification. Blends (B5–B25) were prepared, and nanoparticles (Al₂O₃: 150 ppm; CeO₂: 50 ppm) were dispersed into B20 using ultrasonication and surfactant. Engine tests at varying loads showed that the B20 blend with combined nanoparticles achieved a peak brake thermal efficiency of 34.1%, surpassing diesel (32.5%). Its brake-specific fuel consumption was comparable to diesel. Emissions reduced significantly: carbon monoxide by 55%, unburnt hydrocarbons by 34%, and smoke opacity by 31% versus diesel. Notably, NOx emissions were reduced by 12.4%, countering biodiesel's typical increase. The B20 blend with 150 ppm Al₂O₃ and 50 ppm CeO₂ is identified as an optimal, sustainable alternative fuel requiring no engine modifications.