Ammonia → Urea

This invention relates to an improved process for making urea from ammonia and carbon dioxide. The process is carried out in a reaction vessel which has a zone in which the ammonia and carbon dioxide are reacted to form urea, ammonium carbamate and water, and which also has a zone in which the carbamate is decomposed to ammonia and carbon dioxide. Liquid ammonia is passed in indirect heat exchange relationship with the mixture in the reaction zone, whereby the mixture is cooled and liquid ammonia is vaporized. Ammonia vapor thus produced is passed into the zone in which carbamate is decomposed into ammonia and carbon dioxide to assist in the decomposition of the carbamate. Ammonia and carbon dioxide vapors produced by the decomposition of the carbamate are returned to the reaction zone. A stoichiometric excess of ammonia (that is, more than two moles of ammonia per mole of carbon dioxide and generally from 2.5 to 10 moles of ammonia per mole of carbon dioxide) is introduced into the reaction vessel, and, optionally, means are provided for the recycle of excess ammonia which passes through the reaction vessel unconverted.

1. customThe process is carried out in a reaction vessel
2. customare reacted

ORD record

ord-05ee8da3026d49e18f464985c42a082b

Source dataset

uspto-grants-1976_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US03932504