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

FIELD: synthesis of urea.

SUBSTANCE: method for the synthesis of urea from CO₂ and NH₃. When implementing the method: a) carry out the reaction of CO₂ and NH₃ at a reaction pressure to form an aqueous solution of urea; b) strip off the aqueous solution of urea at a stripping pressure to obtain a purified solution and a gas phase containing ammonia and carbon dioxide, and at the stripping stage, pass said aqueous solution in form of a falling film in a tube bundle with external heating; c) condense the gas phase in at least one condenser at a condensing pressure to form a recycle solution sent back to the reaction stage, thereby forming a synthesis loop; d) generate at least the first steam stream at the first regeneration pressure and the first regeneration temperature using heat removed from the gas phase during condensation step (c); e) use the first steam stream as a heat source in at least one subsequent process step, and f) compress the first steam stream (13) to achieve pressure above the regeneration pressure and a temperature above the regeneration temperature before said use as a heat source in at least one said further step. At the same time, no new CO₂ is added at the condensation stage, and the stage of compressing the first vapor stream (13) is carried out by means of a compressor driven by an electric motor. A unit for synthesis of urea and a method for upgrading the unit are also proposed.

EFFECT: invention makes it possible to optimize operation of the high-pressure circuit while maintaining efficient heat recovery for its use in sections following further in the technological process.

18 cl, 3 dwg