Techno-economic study and process simulation for a small-scale hydrogen production plant based on ammonia decomposition

Hydrogen is a carbon-free fuel and can be expected to play a significant role in the global clean energy transition. In this study, two proposed small-scale hydrogen production plant configurations were designed and simulated for high-purity hydrogen production at a rate of 25 kgH2/day. The feasibility and economic viability of the proposed plant configurations were examined. Additionally, the performance and sensitivity analysis were assessed under different operating conditions. Configuration A proposed to use two reactors for ammonia cracking and H2 separation, respectively. Configuration B considers that the decomposition of ammonia and H2 separation simultaneously occurs in a single integrated reactor. Despite the configuration B was more energy efficient than configuration A but both configurations are applicable. The total H2 production cost of configuration A was 6.39 $/kgH2 and that of configuration B was 6.06 $/kgH2. Since the proposed plant configurations generated both hydrogen and nitrogen, the total cost of production was distributed between them. Therefore, the final H2 and N2 separation costs of configuration A was 5.05 $/kgH2 and 1.14 $/kgN2, and configuration B was 4.72 $/kgH2 and 1.08 $/kgN2. The hydrogen production cost from different ammonia synthesis pathways was compared. The technology readiness level (TRL) for hydrogen production from ammonia cracking was assessed and identified at a range of TRL 4-6. It can also be considered that the ammonia synthesis pathway controlled the ammonia prices and subsequently the hydrogen production cost.