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AssigneeCF Industries, Inc.
InventorsJohn W. Barron, William H. Van Moorsel
Estimating the term…
Disclosed are after-treatment processes and apparatus for synthesis plants, particularly urea and ammonium nitrate plants, but applicable also to various other plants in which the synthesis reaction does not go to substantial completion. In such plants product is fed to an evaporator for concentration and then to a solidification stage. The vaporous overhead stream from the evaporator contains entrained synthesis product, one or more unreacted starting materials, and solvent (usually H.sub.2 O). It is condensed, and the condensate is brought into mass and heat exchange relationship with the vaporous overhead stream from the evaporator substantially without material transfer of solvent to the condensate stream. The condensate stream is thereby enriched in synthesis product, heat is added to it, and unreacted starting material is desorbed from it. The product-enriched condensate is delivered to the solidification stage for processing there. Production capacity is increased and plant effluent is decreased or eliminated.
In a urea process of the kind in which product from a synthesis section is passed through at least one evaporator section for concentration prior to delivery to a solidification section, and in which said evaporator section has a vaporous overhead stream containing entrained urea, CO.sub.2, NH.sub.3, and H.sub.2 O, and further in which at least part of said evaporator section overhead stream is condensed to produce a derivative condensate stream containing dissolved entrained urea, CO.sub.2, and NH.sub.3 ;
In a urea process of the kind in which product from a synthesis section is passed through first and second evaporator sections sequentially for concentration prior to delivery to a solidification section, and in which each of said evaporator sections has an overhead stream containing entrained urea, CO.sub.2, NH.sub.3, and H.sub.2 O, and further in which each of said overhead streams is separately at least partially condensed to produce derivative condensate streams containing dissolved entrained urea, CO.sub.2 and NH.sub.3 ;
In an ammonium nitrate process of the kind in which product from a synthesis section is passed through at least one evaporator section prior to delivery to a solidification section, and in which said evaporator section has a vaporous overhead stream containing entrained ammonium nitrate, NH.sub.3 and H.sub.2 O, and further in which at least part of said evaporator section overhead stream is condensed to produce a derivative condensate stream containing ammonium nitrate and NH.sub.3 ;
In a process of the kind in which relatively nonvolatile product and residual unreacted relatively volatile starting material and solvent are passed through at least one evaporator section for concentration of the product and at least partial removal of starting material and solvent therefrom prior to delivery to a product solidification section, and in which said evaporator section has a vaporous overhead stream containing entrained product, starting material and solvent, and further in which at least part of said evaporator overhead stream is condensed to produce a derivative condensate stream containing dissolved entrained product and starting material;
In a plant of the kind in which relatively nonvolatile product and residual unreacted relatively volatile starting material and solvent are passed through at least one evaporation section for concentration of the product and at least partial removal of starting material and solvent therefrom prior to delivery to a product solidification section, and in which said evaporator section has a vaporous overhead stream containing entrained product, starting material and solvent, and further in which at least part of said evaporator overhead stream is condensed to produce a derivative condensate stream containing dissolved entrained product and starting material;
Dependencies are inferred from the claim text.