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US 12,240,800 B2Granted
Multiproduct low biuret urea production
AssigneeStamicarbon B.V.
InventorsBranislav Manic, Rahul Patil
Life of this patent
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Abstract
Embodiments pertain to a urea plant and to the operation of a urea plant in a reduced load mode. In embodiments, two evaporators in parallel are used, connected to a finishing section respectively to a melamine plant.
Claims15
A method of operating a urea plant in a reduced load mode, the method comprising:
- operating a high pressure urea synthesis section of a urea plant in a reduced load mode;
- subjecting a urea solution stream from the urea synthesis section to purification in a recovery section to give purified urea solution;
- subjecting the purified urea solution to evaporation of water in a first vacuum evaporation stage, to give a first concentrated urea solution;
- subjecting a first part of the first concentrated urea solution to evaporation of water in a first evaporator of a second vacuum evaporation stage to form a first urea melt;
- subjecting a second part of the first concentrated urea solution to evaporation of water in a second evaporator of the second vacuum evaporation stage to form second urea melt;
- wherein the first evaporator is operated at a first operating capacity ratio, as percentage of a design capacity of the first evaporator, and wherein the second evaporator is operated at a second operating capacity ratio, as percentage of a design capacity of the second evaporator, wherein the second operating capacity ratio is lower than the first operating capacity ratio, and wherein the second evaporator has an outlet for the second urea melt connected with an inlet of a melamine plant.
3 more elements
A plant for the production of urea, comprising:
- a urea production section comprising a synthesis section and a recovery section,
- a first vacuum evaporation stage receiving urea solution from the urea production section,
- a second vacuum evaporation stage receiving concentrated urea solution from the first vacuum evaporation stage, comprising a first evaporator and a second evaporator arranged in parallel, both receiving concentrated urea solution from the first vacuum evaporation stage, wherein the first evaporator has an outlet for a first urea melt connected to a finishing section and to a melamine plant, and wherein the second evaporator has an outlet for a second urea melt connected to said melamine plant.
Dependencies are inferred from the claim text.