Urea finishing method
AssigneeStamicarbon B.V.
InventorJohannes Henricus Mennen
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Abstract
Disclosed is a method for urea finishing. A urea solution is subjected to crystallization and, other than in conventional processes, the urea crystals are shaped by exerting mechanical force onto them. Thus, the conventional prilling or granulation finishing steps can be avoided, and so are the corresponding emissions of ammonia and/or dust. The crystallization comprises a flash crystallization. The invention also pertains to the urea particles obtainable by the process, to a urea plant, and to a method of modifying an existing urea plant.
Claims18
A process for the production of urea particles from an aqueous urea solution comprising a crystallization step, wherein the solution is subjected to flashing so as to obtain a solid crystallized urea-containing product and an ammonia and water containing vapor, followed by
- a shaping step, wherein, the shaping step comprises exerting mechanical force on the urea crystals.
A method of modifying an existing urea plant so as to reduce emissions of ammonia and dust there from, the method comprising adding to the plant a device suitable for crystallizing urea from a solution, and a device suitable for exerting mechanical force on urea crystals.
A method for increasing the plant capacity of a urea plant by increasing the capacity of a finishing section of said plant, the method comprising adding as a parallel finishing section a device suitable for crystallizing urea from a solution by dry flashing, and a device suitable for exerting mechanical force on urea crystals.
Dependencies are inferred from the claim text.