摘要 |
An ammonia production process comprises steam hydrocarbon primary reforming, air secondary reforming, carbon monoxide hift, carbon oxides removal, ammonia synthesis and discarding of non-reactive gases and is made more economical in energy consumption by using excess air in secondary reforming and treating the synthesis gas to separate a hydrogen-enriched stream and returning that stream to the synthesis. Preferably the synthesis gas after carbon moxides removal is compressed if at all by no more than 50% and consequently the process can be carried out in a plant having a gas circulator but no compressor. Preferably synthesis is at a pressure in the range 40-80 bar abs. and at an outlet temperature in the range 350 DEG -430 DEG C. over a catalyst containing iron, cobalt and promoting compounds. Recovery of the hydrogen-enriched stream is preferably from a side stream of synthesis gas. |