<![CDATA[Ammonia–hydrogen dual-fuel combustion offers a promising pathway for dispatchable low-carbon power generation, yet its practical viability depends on balancing efficiency, cost, and nitrogen-based emissions. This study aimed to evaluate the thermodynamic, economic, and environmental performance of ammonia–hydrogen combustion in an advanced internal combustion engine. A quantitative experimental design combined single-cylinder engine testing, thermo-economic modeling, life-cycle emission assessment, statistical analysis, and multi-objective optimization. Hydrogen energy fractions from 0% to 40% were examined across multiple loads and ignition settings, with selected tests incorporating exhaust-gas recirculation. Results showed that hydrogen enrichment shortened ignition delay, improved combustion stability, increased brake thermal efficiency, and reduced ammonia slip and nitrous oxide emissions. Hydrogen fractions between 20% and 30% provided the most balanced performance, while 40% enrichment produced only marginal efficiency gains and higher nitrogen-oxide emissions and electricity costs. A 30% hydrogen fraction with 10% exhaust-gas recirculation maintained 37.60% brake thermal efficiency and reduced nitrogen oxides by more than 40%. Renewable fuel pathways achieved the lowest life-cycle emissions but the highest levelized electricity cost. The study concludes that coordinated optimization of fuel composition, combustion control, emission mitigation, and fuel-production pathways is essential for credible decarbonized power generation under technically stable and economically plausible operating conditions at scale.]]>
