Abstract: A method for producing a SNCR/SCR solution, comprising the steps of: a) reacting ammonia and carbon dioxide in a high pressure section, thereby obtaining an aqueous composition comprising urea and ammonium salts; b) processing the aqueous composition obtained in step a), thereby obtaining a first aqueous solution comprising urea, and a second aqueous solution comprising ammonium salts; and c) diluting the second aqueous solution comprising ammonium salts obtained in step b) with a third aqueous solution, thereby producing the SNCR/SCR solution. The present disclosure also provides the use of an aqueous stream comprising ammonium salts from a urea-producing plant for producing a SNCR/SCR solution.

Abstract: A pipe reactor, especially for production of UAS, includes a tubular body and a reactor head, wherein the reactor head has a device for axial injection of acid, a device for injection of ammonia, a device for supply of urea and a reaction chamber, where acid and ammonia can react before coming into contact with urea.

Abstract: Pipe reactor, especially for production of UAS, comprising a tubular body 14 and a reactor head 1, wherein the reactor head has means (3,3A) for axial injection of acid, means (2,2A) for injection of ammonia, means (7) for supply of urea and a reaction chamber (zone 3A, 2A), where acid and ammonia can react before coming into contact with urea.