Catalytic enhancement of engine performance and sustainability using metallic nanoparticles with third-generation silkworm biodiesel

Abstract

This study investigates the role of metallic nanoparticles (TiO₂ and Al₂O₃) in enhancing the performance and sustainability of third-generation silkworm biodiesel in a single-cylinder CI engine. Structural analysis confirmed high crystallinity of TiO₂ by 16.26 nm and Al₂O₃ by 15.65 nm. Test blends were prepared by enriching a baseline 20% silkworm biodiesel-diesel blend (S20) with TiO₂ and Al₂O₃ nanoparticles at 50 and 100 ppm (S20T50, S20T100, S20A50 and S20A100). Among the tested fuels, the S20T100 blend showed better performance than neat diesel and other test fuels. Combustion analysis indicated that S20T100 reached a peak in-cylinder pressure of 67 bar and heat release rate of 49 J/CAD, corresponding to increases of 31% and 16% over diesel. In terms of emissions, S20T100 reduced UBHC from 78 ppm to 68 ppm, lowered CO from 0.597% to 0.43%, representing a 28% reduction and decreased smoke opacity by 3.5% compared to diesel. Nitrogen oxide emissions for S20T100 were 1020 ppm, slightly lower than diesel at 1087 ppm and remained lower than those of the base S20 biodiesel blend. These results indicate that the S20T100 blend of silkworm biodiesel enriched with TiO₂ nanoparticles improves fuel efficiency and reduces pollutant emissions, offering a sustainable and cleaner alternative to conventional diesel without any engine modifications.