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AssigneeToyo Engineering Corporation
InventorsHaruyuki MORIKAWA, Shuhei NAKAMURA, Keishi SATO
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The present invention relates to a method for producing a high-purity aqueous urea solution, utilizing a urea production process at least including a urea synthesis step of synthesizing urea from a raw material feed to produce a urea synthesis liquid, and a urea purification step of purifying the urea synthesis liquid to produce an aqueous urea solution with high urea concentration. The present invention includes a urea crystallization step of separating a part of the urea synthesis liquid and/or a part of the aqueous urea solution and crystallizing urea contained in the separated urea synthesis liquid and/or aqueous urea solution to produce solid crystal urea, and a mixing step of mixing the crystal urea with water to produce a high-purity aqueous urea solution. A high-purity aqueous urea solution to be produced is an aqueous urea solution with high purity suitable as a reducing agent for SCR.
A method for producing a high-purity aqueous urea solution in a urea production process, the process comprising at least a urea synthesis step for synthesizing urea from a raw material feed to produce a urea synthesis liquid and a urea purification step for purifying the urea synthesis liquid to produce an aqueous urea solution having high urea concentration, wherein the method further comprises:
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