Secondary reforming is a key process step in the production of hydrogen for ammonia synthesis via the Haber–Bosch process. Following primary steam reforming of natural gas to synthesis gas using ReforMax® 330, secondary reforming is carried out with the addition of air to introduce the nitrogen (N₂) required for the H₂–N₂ synthesis gas mixture.
In the secondary reformer, oxygen (O₂) contained in the air is completely consumed by reacting with unconverted natural gas, residual steam (H₂O), and the partially reformed synthesis gas. This highly exothermic reaction is catalyzed by ReforMax® 410 and results in an N₂-containing synthesis gas with a suitable composition for downstream processing.
The synthesis gas is subsequently routed to carbon monoxide conversion via high-temperature and low-temperature water gas shift reactions (HTS and LTS), followed by H₂O and CO₂ removal. A final methanation step removes residual carbon monoxide (CO) to achieve the required purity of the H₂–N₂ feed gas for ammonia synthesis.
