FIELD: chemical industry; methods of production of carbamide out of the ammonia and carbon dioxide.
SUBSTANCE: the invention is pertaining to the method of production of carbamide out of the ammonia and carbon dioxide. The method of production of carbamide is realized by interaction of ammonia and carbon dioxide in the reactor with production of the reaction mixture containing carbamide, ammonium carbamate and the free ammonia in the water solution, which is evaporated, using as the evaporating gas the whole stream of the fresh carbon dioxide. As a result of evaporation produce the first stream in the vapor phase, which contains ammonia, carbon dioxide and carbamate, and also the liquid stream containing carbamide and the rest of the carbamate in the water solution, which is routed into the section of separation of carbamide, where the water solution of carbamate is separated from carbamide. The first vaporous stream is divided into two parts, one of which is returned in the reactor, and the other is practically completely condensed and the produced water solution of carbamate is also routed into the reactor, and the separated second vaporous stream of the non-reacted ammonia and carbon dioxide is exposed to the repeated evaporation and division into the gaseous phase composed out of ammonia and the carbon dioxide being returned into the reactor, and the liquid phase which contains carbamate. The installation used for realization of the method includes the reactor, two evaporators for the reaction mixture and the separated water solution of ammonium carbamate, the condenser for practically complete condensation of the first part of the first vaporous stream, the pipe ducts for pumping through of the liquid and vaporous streams. The technical result of the invention is the rise of conversion of the raw at the expense of usage of recycling of the non-reacted ammonia and carbon dioxide, improvement of the energy and economic indicators of the production process.
EFFECT: the invention ensures the increased conversion of the raw due to usage of recycling of the non-reacted ammonia and carbon dioxide, the improved energy and economic indicators of the production process.
9 cl, 1 dwg
