Ammonia synthesis argon recovery

HARP [Hybrid argon recovery process] A process for extracting argon from the hydrogen recycle stream in ammonia synthesis. Both PSA and a cryogenic process are used. Krishnamurthy, R., Lemer, S. L., and MacLean, D. M., Gas Sep. Purif, 1987,1, 16. 

HARP [Hybrid Argon Recovery Process] A process for extracting argon from the hydrogen recycle stream in ammonia synthesis. Both PSA and a cryogenic process are used. 

Innovations for the ammonia synthesis loop include the recovery of argon and hydrogen. 

Conventional reforming with methanation as the final purification step produces a synthesis gas that contains inerts (CH4 and argon) in quantities that do not dissolve in the condensed ammonia. Most of the inerts are removed by taking a purge stream out of the synthesis loop. The size of this purge stream controls the level of inerts in the loop at about 10% to 15%. The purge gas is scrubbed with water to remove ammonia and then it can be used as fuel or sent to hydrogen recovery. 

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