| 摘要 |
The present invention relates to a process and apparatus for the preparation of urea, and in particular for urea obtained from ammonium carbamate formulated from carbon dioxide and ammonia at a pressure of about 125 bar to about 350 bar in a urea synthesis solution in a urea reactor. The reactor defines a horizontally arranged condensation zone and contains a heat exchanger. According to this process, NH3 and CO2 are supplied to the reactor and are largely absorbed into the urea synthesis solution. A substantial portion of the heat formed in the condensation is discharged by means of the heat exchanger. The residence time of the urea synthesis solution in the reactor preferably is selected so that at least about 85% of the theoretically obtainable amount of urea is prepared. Thereafter, the urea synthesis solution can be processed into a urea solution or solid urea.
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