Synergistic effect of nano additives for combustion and emission mitigation in a hydrogen-enriched CI engine using cocos nucifera oil methyl ester

Abstract

This research investigates the utilization of Cocos Nucifera methyl ester (COBD) biodiesel blends in diesel engines to improve energy efficiency and diminish hazardous emissions by the incorporation of nanoparticles into the fuel and the introduction of enriched hydrogen into the combustion chamber. COBD mixtures of 30% and 40% were synthesized utilizing methoxide as a catalyst. A quantity of 30 ppm alumina nanoparticle (Al₂O₃) was incorporated into the biodiesel blend using an ultrasonicator to mitigate cold flow and viscosity constraints of biodiesel. Enriched hydrogen was delivered at flow rates of 8 LPM and 10 LPM through the input manifold, accompanied by air, at the fuel condition of 40COBD +30Al₂O₃. At a hydrogen flow rate of 10 LPM with 40COBD +30 ppm Al₂O₃, notable enhancements were recorded: a 25.98% decrease in brake specific fuel consumption (BSFC), a 6.86% increase in brake thermal efficiency (BTE), and reductions in carbon monoxide (CO) by 54.12%, unburned hydrocarbons (UBHC) by 15.95 ppm, and smoke opacity by 14.70%, in comparison to conventional diesel. Nonetheless, NOx emissions increased by 604 ppm as a result of elevated combustion temperatures. The synergistic application of COBD biodiesel, alumina nanoparticles, and enriched hydrogen significantly enhances engine performance and diminishes emissions, with the exception of elevated NOx levels.