Sustainable engine transformation: assessing hydrogen enrichment and CeO₂ nanoparticle effects on neat palm biodiesel-fueled CI engines

This study investigates the potential utilization of pure palm biodiesel in compression ignition (CI) engines, exploring the impact of enriched hydrogen-air supplied at the inlet manifold and the incorporation of nanoparticles into the fuel. The experimental campaign encompasses different fuel types: neat palm biodiesel (POBD), palm biodiesel with enriched hydrogen at a flow rate of 10 L per minute (lpm) mixed with air (POBD + H₂), and palm biodiesel with 30 ppm cerium oxide nanoparticles and enriched hydrogen-air (POBD + H₂ + CeO₂). The engine’s performance is compared against that of neat diesel fuel. The testing of hydrogen-enriched air with palm biodiesel (POBD + H₂) yields an average reduction of 14.29% in specific fuel consumption (SFC), a 4.06% increase in brake thermal efficiency (BTE), and significant reductions in exhaust pollutant emissions: carbon monoxide (CO) by 31.77%, hydrocarbon (HC) by 25.2 ppm, and smoke opacity by 47.37%. However, the emission of nitrogen oxides (NOx) increases by 194.6 ppm compared to diesel fuel. Upon the introduction of cerium oxide nanoparticles into the aforementioned experimental setup (POBD + H2 + CeO2), significant enhancements were seen, including a reduction of 20.67% in SFC and a 6.28% increase in BTE. The levels of polluting gases exhibited significant reductions. Specifically, CO levels decreased by 42.25%, HC levels decreased by 29.6 ppm, smoke opacity decreased by 57.01%, and there was a remarkable decrease of 59 ppm in nitrogen oxide levels as compared to the use of diesel fuel.