Low-carbon ammonia production via methane pyrolysis: Integrated process development toward turquoise ammonia

Achieving meaningful decarbonization in ammonia production is highly dependent on adopting hydrogen generation routes that offer reduced CO₂ emissions routes without compromising industrial productivity. In the present study, an integrated process model that couples high-temperature methane pyrolysis with a multi-stage ammonia synthesis loop is developed to explain thermodynamic and process-level interactions. Integrated thermodynamic modeling, heat-integration analysis, and system-level optimization provide a systematic assessment of energy efficiency, hydrogen use, and emissions in the designed low-carbon ammonia production system. Sensitivity analyses are performed by varying the key operating parameters and demonstrate that elevated pyrolysis temperature improves hydrogen availability by ∼3 %. Results reveal that increased ammonia synthesis pressures raise ammonia formation while temperature plays a contrary role owing to the exothermic nature of reaction. Integrated temperature–pressure performance maps highlight distinct operating regions to maximize hydrogen utilization, ammonia conversion, and energy efficiency. It was also confirmed that multi-bed synthesis with intercooling significantly improves equilibrium approach while upstream hydrogen (pyrolysis) quality strongly affects reactor heat duty and overall process efficiency. This modeling framework offers a technically robust basis to optimize low-carbon ammonia production and supports future research on kinetic refinement, advanced thermal-integration design, techno-economic assessment, and life cycle assessment of low-carbon ammonia pathways.