METHOD AND UNIT FOR UREA SYNTHESIS Russian patent published in 2023 - IPC C07C273/04 B01J19/00 B01J19/24 B01J3/04 

FIELD: synthesizing urea.

SUBSTANCE: method for synthesizing urea from ammonia and carbon dioxide. In the proposed method urea synthesis is performed with a stripping process in a synthesis section, including at least a reactor, a stripper and a condenser; converting ammonia and carbon dioxide into urea in a reactor at synthesis pressure to form an exhaust aqueous stream containing urea and unconverted ammonium carbamate; performing a reactor effluent stripping step in a stripper where the reactor effluent is heated and contacted with carbon dioxide gas acting as a stripping agent to form a urea-containing solution and stripper vapours containing predominantly ammonia and carbon dioxide; the urea-containing solution leaving the stripper is sent to the low-pressure regeneration section for further processing. The gaseous carbon dioxide supplied to the stripper represents the total amount of fresh carbon dioxide introduced into the synthesis section, and the vapours of the stripper are divided into a first part sent to the reactor and a second part sent to the condenser, the condenser being a shell-and-tube evaporative condenser with the tube space and the inter-tube space, and the second part of the stripper vapor is directed into the tube space for condensation. The carbamate-containing condensate stream is removed from the condenser tube space and returned to the reactor. A unit for urea synthesis is also proposed.

EFFECT: invention is aimed at reducing material costs for equipment and creating a low-height synthesis circuit, the construction of which is simple and less expensive compared to existing technical solutions.

16 cl, 1 dwg