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

FIELD: urea synthesis.

SUBSTANCE: present invention relates to a method for synthesizing urea from ammonia and carbon dioxide. The proposed method includes: urea synthesis in a first urea synthesis section, including at least one first urea reactor (1), operating at a first urea synthesis pressure and producing a first reaction product (10) containing urea; urea synthesis in a second urea synthesis section including at least one second urea reactor (2), operating at a second urea synthesis pressure less than the first urea synthesis pressure, and producing a second reaction product (21) containing urea; a step of stripping the first reaction product, carried out in a stripping section including at least one stripping column (4) operating at a stripping pressure less than the first synthesis pressure, to produce a liquid stripping stream (11) containing urea and a gas phase (12), containing ammonia vapour and carbon dioxide. In this case, the second product (21) of the reaction and the liquid stream (11) of the stripping column are sent to the regeneration section (13), where a recirculated solution (17) containing carbamate is produced, and said recirculated solution (17) is partially sent to the first reactor and partially into the second reactor. A plant for producing urea is also proposed.

EFFECT: invention is aimed at achieving greater flexibility and energy efficiency compared to known technologies, in particular, it ensures the generation of steam in accordance with the needs of further processes.

19 cl, 3 dwg, 3 ex