| CPC C07C 273/04 (2013.01) | 20 Claims |
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1. A process for the production of urea from ammonia and carbon dioxide in a urea plant,
wherein the urea plant comprises a high pressure (HP) synthesis section comprising a reaction zone, a carbamate condenser and a stripper,
wherein the carbamate condenser comprises a shell-and-tube heat exchanger with a shell space and a first and a second horizontal tube bundle,
wherein the process comprises:
forming a urea synthesis solution comprising urea, water and ammonium carbamate in said reaction zone,
condensing gas from the stripper in the shell space thereby providing a carbamate-containing high pressure liquid stream;
expanding said urea synthesis solution from said synthesis section to medium pressure (MP) to give a first MP urea solution comprising carbamate;
heating said first MP urea solution in said first tube bundle, thereby decomposing said carbamate comprised in said first MP urea solution;
subjecting a fluid stream from the outlet of said first tube bundle to gas/liquid separation to give a second MP urea solution and an MP gas stream;
condensing said MP gas stream at medium pressure in a first condensation compartment thereby forming carbamate and heating through indirect heat exchanging contact a urea solution to be heated giving heated urea solution in a first evaporation stage; and
raising steam in said second tube bundle and using said steam to further heat through indirect heat exchanging contact said heated urea solution in a second evaporation stage.
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