Ammonia plant upgrade and purge gas recovery
Cryogenic purge gas recovery units are very tolerant to increased flow from ammonia plant debottlenecking, especially the cryogenic cold box section. However, overload of the dehydration system upstream of the cold box can lead to fouling, loss of hydrogen recovery performance and the need for costly shutdown and thaw. Awareness of key plant parameters and some simple precautions can avoid such problems. A. J. Finn and T. R. Tomlinson of Costain provide some guidance.