Numerical investigation of sorption-enhanced ammonia synthesis for hydrogen storage: CFD modeling, experimental validation, and scale-up

Ammonia (NH₃) is increasingly recognized as a clean hydrogen (H₂) carrier due to its high H₂ content, carbon neutrality, and ease of storage and transport. Realizing its potential as an energy vector requires synthesis technologies that operate under mild conditions and are compatible with water electrolysis. This study develops a comprehensive computational fluid dynamics (CFD) model of sorption-enhanced NH₃ synthesis with alternating catalyst and sorbent layers, validated against experimental data, to elucidate the in-situ sorption effects. The model is subsequently employed to scale up the process and to optimize the operation conditions of a pilot-scale reactor. Results indicate a 66.8% increase in H₂ conversion with a six-layer configuration, while a 60-layer pilot reactor achieves over 90% conversion and 99.5% NH₃ capture in single-pass operation. These findings demonstrate the scalability and potential of sorption-enhanced NH₃ synthesis, providing a moderate and efficient pathway for H₂ storage and transport.