PROCESS FOR PREPARING UREA FROM AMMONIA AND CARBON DIOXIDE

摘要

1447914 Urea UNIE VAN KUNSTMESTFABRIEKEN BV 21 May 1974 [21 May 1973] 22595/74 Heading C2C Urea is synthesized from ammonia and carbon dioxide in a reaction zone containing a stripping zone for the reaction products which is substantially isobaric with, and in heatexchange relationship through one or more surfaces with the reaction zone, in which stripping zone ammonium carbamate is decomposed and the decomposition products are expelled with gaseous carbon dioxide, ammonia and/or inert gas, the reaction zone being maintained at 210‹ to 245‹ C. and 250 to 600 atmospheres, the molar ratio of ammonia to carbon dioxide in the liquid phase in the reaction zone being between 2À5 and 8 : 1, and at least a part of the gas mixture discharged from the stripping zone being introduced into the bottom part of the reaction zone.