| 摘要 |
<p>A process for the production of urea from ammonia and carbon dioxide in an NH3:CO2 molar ratio of from 5:1 to 8:1 comprises the synthesis of a urea solution in a synthesis reactor and the decomposition of ammonium carbamate contained in the resulting urea solution in two stages in decomposers, the first stage using ammonia as the stripping agent and the second stage using carbon dioxide as the stripping agent. The synthesis and the first decomposition stage are carried out under a pressure equal or substantially equal to each other, which pressure is from 180 to 250 bars, whereas the second decomposition stage is carried out under a pressure of from 30 to 50 bars lower than the pressure used in the first decomposition stage.</p> |
