Urea synthesis using excess ammonia

Claim 1

IN A SOLUTION RECYCLE PROCESS FOR THE SYNTHESIS OF UREA FROM CARBON DIOXIDE AND EXCESS AMMONIA WHEREIN ONE MOL OF CO2 AND 4-5 MOLS OF NH3 ARE REACTED IN A REACTION ZONE AT TEMPERATURES OF THE ORDER OF 180*C. AND PRESSURES OF THE ORDER OF 280 ATMOSPHERES TO FORM A UREA MELT AND WHEREIN UNREACTED NH3 AND CO2 SEPERATED FROM THE UREA MELT ARE RECOVERED AND RE-UTILIZED IN THE UREA SYNTHESIS, THE STEPS COMPRISING (A) SUBJECTING UREA MELT WITHDRAWN FROM SAID REACTION ZONE TO A FIRST REDUCED PRESSURE FOR SEPARATING THEREFROM A FIRST GASEOUS MIXTURE COMPRISING NH3 IN EXCESS AND CO2, (B) SCRUBBING SAID FIRST GASEOUS MIXTURE WITH WATER TO PROVIDE RESPECTIVE PURE NH3 AND AN AQUEOUS AMMONIUM CARBONATE DELIVERING UNDER PRESLIQUEFYING THE SAID PURE NH3 FOR DELIVERING UNDER PRESSURE FOR REUSE IN THE REACTION ZONE AND PASSING THE AQUEOUS AMMONIUM CARBONATE SOLUTION TO A MIXING CHAMBER, (D) SUBJECTING THE UREA MELT FROM WHICH THE SAID FIRST GASEOUS MIXTURE HAS BEEN SEPERATED TO A SECOND AND FURTHER REDUCED PRESSURE FOR SEPARATING THEREFROM A SECOND GASEOUS MIXTURE COMPARISING NH3 AND CO2 AND H2O VAPOR, (E) DEHUMIDIFYING THE SAID SECOND GASEOUS MIXTURE FOR REDUCING THE H2O CONTENT THEREOF, AND (F) INTRODUCING THE DEHUMIDIFIED SECOND GASEOUS MIXTURE INTO THE AMMONIUM CARBONATE SOLUTION IN THE CHAMBER FOR ABSORPTION THEREBY FOR PRODUCING AN AMMONIUM CARBONATE SOLUTION OD LOW H2O CONTENT FOR DELIVERY UNDER PRESSURE FOR USE IN THE REACTION ZONE