Patent ID: 11912649

Abstract:
Disclosed is a method for the removal of ammonia from the off-gas of a finishing section of a urea production plant. Also disclosed is a corresponding urea plant, and a method of accordingly modifying a pre-existing urea plant. In a scrubbing section, the off-gas is brought into contact with an acidic scrubbing liquid so as to provide a scrubbed off-gas and a utilized scrubbing liquid comprising ammonium salt. The method specifies an evaporation section, which is part of the urea plant that produces urea melt, that is divided into first and second stages. The first stage is part of the urea melt production plant. The second stage decoupled, as regards recirculation of liquids other than the urea product stream, from the urea melt production plant. This is accomplished by sending utilized scrubbing liquid that contains ammonium salts to the second stage evaporation section, and by sending condensed vapours from said second stage evaporation section to said scrubbing section.