METHOD FOR REVAMPING A SELF-STRIPPING UREA PLANT AND PROCESS FOR SYNTHESIS OF UREA Russian patent published in 2016 - IPC C07C273/04 

FIELD: processes.

SUBSTANCE: invention relates to revamping a self-stripping urea plant comprising high pressure urea synthesis section which includes at least a reactor, a thermal or ammonia stripper and a condenser, a medium pressure treatment section and a low pressure recovery section. Method includes following steps: intermediate recovery section (30) is installed and connected between high-pressure synthesis section and medium-pressure section: a stream of urea solution (14A, 15A) which is produced in high pressure section, is directed to said intermediate section (30); a flow of concentrated solution (15B) from said intermediate section is directed to said medium pressure section; said intermediate recovery section (30) being suitable to decompose carbamate and recover a carbamate solution from said stream of urea solution, operating at an intermediate pressure which is lower than working pressure of said synthesis section and greater than working pressure of said medium pressure section, obtaining said flow of concentrated solution (15B) at said intermediate pressure. Also self-stripping method for urea synthesis and plant for urea production are suggested.

EFFECT: invention makes it possible to increase self-stripping urea plant capacity.

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