Performance and emission assessment of Al2O3 and Fe2O3 nanoparticle enhanced biodiesel blends using Taguchi ANOVA optimization

Abstract Improving the thermal efficiency and reducing toxic emissions in compression ignition (CI) engines remains a major challenge for sustainable transportation. This research presents a three-phase experimental assessment of the synergistic influence of metal-oxide nanoparticles and ethanol on the performance, combustion, and emission properties of a compression ignition engine fuelled of biodiesel-diesel blends. Phase 1, involved a comparative characterization of the performance and emission profiles of Dairy Scum (DSB20) and Pongamia (PB20) biodiesel blends enhanced with Al 2 O 3 and Fe 2 O 3 nanoparticles were conducted. In phase II, a Taguchi L9 orthogonal array was used to determine the statistical significance of fuel type, nanoparticle concentration, establishing PB20 with 150 ppm-Fe 2 O 3 as the optimal candidate for subsequent enrichment. In phase III, a confirmatory experimental run was conducted to validate the optimized blend with ethanol (10% v/v). Statistical analysis revealed that the feedstock type is the primary determinant for brake thermal efficiency (BTE), and peak cylinder pressure (P max ). Experimental data indicate that while nanoparticles alone improved thermal efficiency, the finally ternary blend (PB20-Fe 2 O 3 -E10) achieved a synergistic peak BTE of 26.85% (a 14.2% increase over diesel) and a 14.7% reduction in BSFC, while successfully regulating NOx emissions.