Hydrogen‐Enriched Microbial Oil Biodiesel With Hybrid Nanoparticles Impact on Diesel Engine Efficiency and Emissions

ABSTRACT This study examines a dual‐fuel enhancement strategy that combines hydrogen enrichment with hybrid nanoparticle (HNP) doping. The aim is to improve combustion, performance, and emission characteristics of microbial oil biodiesel (MOB) in compression ignition engines. Previous biodiesel research mostly investigated hydrogen (H 2 ) and nanoparticles separately. In contrast, this work investigates their synergistic effects in MOB applications. The experimental objectives were to analyze the influence of metal‐based (cerium oxide [CeO2]–aluminum oxide [Al 2 O 3 ]) and carbon‐based (graphene oxide [GO]–carbon nanotubes [CNTs]) HNPs on fuel reactivity. It also evaluated the effect of H 2 enrichment at 5 L per minute (lpm) on premixed combustion and determined the combined impact on performance characteristics. MOB blended with GO, CNTs, and H 2 achieved a 12.21% increase in brake thermal efficiency (BTE) and a 15.02% reduction in brake specific energy consumption (BSEC) compared to diesel at maximum load. Emissions of carbon monoxide (CO), hydrocarbons (HC), and smoke opacity were reduced by 22%, 25%, and 30% respectively, while nitrogen oxides (NOx) increased by 14.18%. Enhanced in‐cylinder heat transfer, improved flame propagation, and reduced diffusion losses led to superior thermal and combustion efficiency. In summary, this study offers insights into H 2 ‐assisted, nanoparticle‐augmented MOB combustion, addressing a significant research gap in low‐carbon engine fuels. The results indicate that this approach is both scalable and environmentally sustainable, providing cleaner diesel alternatives and supporting global net‐zero emission targets as well as United Nations Sustainable Development Goals 7, 9, and 13.