Ammonia as a hydrogen carrier: Simulation study of the ammonia cracker on thermo-fluid stability and key factors for scale-up

A typical technical problem in a hydrogen society is the difficulty in securing the economic efficiency of hydrogen storage and long-distance transportation. Hydrogen carriers that can convert hydrogen into other compounds are required to overcome this issue. Ammonia has many practical advantages as a hydrogen carrier and is drawing attention as a suitable substance. Therefore, a cracking technology that converts ammonia into high-purity hydrogen is necessary. In this study, a numerical computational fluid dynamics model of an ammonia cracker was developed. The flow and heat transfer characteristics were analyzed using a numerical model. The results showed that a nonuniform temperature distribution caused local cracking of ammonia and adversely affected the hydrogen production process. This results of this study can be used to help design large-scale ammonia crackers and efficient hydrogen production processes and contribute to building infrastructure for hydrogen storage/transport/utilization systems.