Patent ID: 8808517
Filing Date: 2014-08-19
Classification: B01D,C02F,C07C,Y02A

Abstract:
1. A process for the removal of ammonia from an ammonia-containing gas stream which comprises: (a) treating ammonia in an ammonia-containing gas stream with an acid to form an aqueous stream comprising an ammonium salt, (b) treating the aqueous stream comprising the ammonium salt with electrodialysis to thereby recover the acid and form an aqueous stream consisting of ammonium hydroxide, (c) heat treating the aqueous stream consisting of ammonium hydroxide to thereby form a gaseous ammonia stream, and (d) recycling the gaseous ammonia stream to a process for the production of urea, wherein the ammonia-containing gas stream is an off-gas stream from a prilling or granulation section of a process for the production of urea.