METHOD FOR PRODUCING FORMALDEHYDE-STABILISED UREA Russian patent published in 2021 - IPC C07C273/02 C07C29/151 C01B3/02 C01C1/04 

FIELD: chemistry.

SUBSTANCE: present invention relates to a method for producing stabilised urea. Described is a method for producing formaldehyde-stabilised urea, including the stages of: producing synthesis gas; subjecting the synthesis gas to one or several stages of conversion of water gas in one or more water gas conversion reactors, forming converted gas; cooling the converted gas below the dew point and extracting the condensate, forming dried converted gas; extracting carbon dioxide from the dried converted gas in the carbon dioxide removal unit, forming carbon dioxide depleted synthesis gas; synthesising methanol from the carbon dioxide depleted synthesis gas in the methanol synthesis unit and extracting methanol and methanol synthesis exhaust gas; subjecting part of the extracted methanol to oxidation by air, forming formaldehyde in the stabiliser production unit; subjecting the methanol synthesis exhaust gas to methanation in the methanation reactor containing a methanation catalyst, forming synthesis gas for production of ammonia; synthesising ammonia from the synthesis gas for production of ammonia in the ammonia production unit and extracting ammonia; interacting part of the ammonia and part of the flow of the extracted carbon dioxide in the urea production unit, forming a flow of urea; and stabilising the urea by mixing the flow of urea and the stabiliser made using the formaldehyde produced in the stabiliser production unit, wherein the carbon dioxide removal unit operates by absorption using a liquid absorbent and comprises an absorbent regeneration unit, wherein the method includes extracting a flow of gas containing carbon dioxide from the absorbent regeneration unit, compressing at least part of the flow of regenerated gas containing carbon dioxide, forming a flow of compressed gas containing carbon dioxide, and passing the flow of compressed gas to the methanol synthesis unit.

EFFECT: invention increases the overall efficiency and flexibility of the urea production processes.

20 cl, 1 dwg, 6 tbl, 2 ex