Integrated process and plant for the production of urea and UAS (urea-ammonium sulfate) mixtures

摘要

An integrated process for the production of urea and UAS is: a urea synthesis step performed by a urea synthesis reactor (4); the urea solution generated in the urea synthesis step has at least one recovery section (5, 6, 7) And a concentration step for collecting unreacted ammonia, carbon dioxide, and water from the urea solution by the concentration section (8), and ammonium sulfate by the reaction of sulfuric acid and ammonia in the ammonium sulfate generator (3). Mixing the ammonium sulphate with the concentrated urea coming from the concentration section (8) to form a UAS mixture; in the ammonium sulphate generation step, at least a portion of the ammonia recovered from the recovery and concentration step Contains It is provided by at least one off-gas.