FIELD: production of carbamide. SUBSTANCE: carbamide is produced due to interaction of ammonia with carbon dioxide in two reaction zones working in parallel. Liquid reaction mixtures obtained in first and second reaction areas contain carbamide, carbamate and free ammonia in aqueous solution which are combined in one flow are subjected to partial decomposition of carbamate at separation of flow of free ammonia at stages of decomposition and extraction of carbamide. As a result, flow of ammonia and carbon dioxide vapors and flow containing undercomposed carbamate in aqueous solution are obtained and are directed to second reaction area. Partial decomposition of carbamate is preferably effected at pressure equal to pressure in second reaction area. Plant proposed for production of carbamide includes two reactors for synthesis of carbamide which work in parallel and desorbent for partial decomposition of carbamate in flow directed from carbamide extraction section. Besides that, this plant has equipment for partial condensation of vapors taken from desorber and delivery of part of concentrated carbamate to second reactor. Method of updating the plant consists in mounting additional adsorber and items of equipment for return of secondary flows of concentrated carbamate with stage of carbamate decomposition and carbamide extraction to second reactor. EFFECT: enhanced efficiency. 10 cl, 1 dwg
