A PROCESS FOR MANUFACTURING UREA

摘要

Urea is prepd. from CO2 and excess NH3 with recycling an NH3CO2 condensate via an ejector using NH3 and H2NCO2NH2 soln. as operating fluid. The process comprises a) reacting CO2 and excess NH3 at urea synthesis temp. and pressure to form a urea synthesis prod. stream contg. urea, H2O, NH3, and H2NCO2NH2, b) seperating a major portion of NH3 and H2NCO2NH2 as gas mixt. of NH3 and CO2 from an aq. soln. of urea and the remained H2NCO2NH2, c) condensing the gas mixt at urea synthesis pressure in presence of H2O to form a liq. condensate, d) siphoning the liq. condensate in an ejector to increase its pressure, e) recycling the pressurized condensate to the urea synthesis reactor.