Urea production method and urea production apparatus
AssigneeToyo Engineering Corporation
InventorsTakahiro YANAGAWA, Yasuhiko KOJIMA, Keiji SANO, Shogo KAWATA
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Abstract
Provide are a urea production method and a urea production apparatus in which hydrogen and oxygen are produced by electrolysis of water in an electrolysis unit, nitrogen is separated and recovered from air in an air separation unit, ammonia is synthesized in an ammonia synthesis unit using hydrogen from the electrolysis unit and nitrogen from the air separation unit as raw materials, carbon dioxide is produced by combusting a fuel in an oxycombustion unit while using at least the oxygen from the electrolysis unit, and urea is synthesized in a urea synthesis unit by using the carbon dioxide and the ammonia as raw materials.
Claims10
A urea production method with a reduced excess amount of ammonia and improved material balance comprising
- an electrolysis step of producing hydrogen and oxygen by electrolysis of water;
- an air separation step of separating and recovering nitrogen from air and producing gas containing high concentration oxygen;
- an ammonia synthesis step of synthesizing ammonia by using at least part of the hydrogen produced in the electrolysis step and at least part of the nitrogen separated and recovered in the air separation step as raw materials;
- an oxycombustion step of producing carbon dioxide by combusting a fuel while at least using at least part of the oxygen produced in the electrolysis step and at least part of the gas containing high concentration oxygen produced in the air separation step;
- and
- a urea synthesis step of synthesizing urea by using at least part of the carbon dioxide produced in the oxycombustion step and at least part of the ammonia produced in the ammonia synthesis step as raw materials.
(canceled)
A urea production apparatus with a reduced excess amount of ammonia and improved material balance comprising
- an electrolysis unit (E) for producing hydrogen and oxygen by electrolysis of water;
- an air separation unit (A) for separating and recovering nitrogen from air and producing gas containing high concentration oxygen;
- an ammonia synthesis unit (N) for synthesizing ammonia by using at least part of the hydrogen produced in the electrolysis unit (E) and at least part of the nitrogen separated and recovered in the air separation unit (A) as raw materials;
- an oxycombustion unit (O) for producing carbon dioxide by combusting a fuel while at least using at least part of the oxygen produced in the electrolysis unit (E) and at aleast part of the gas containing high concentration oxygen produced in the air separation unit (A) as raw materials;
- and
- a urea synthesis unit (U) for synthesizing urea by using at least part of the carbon dioxide produced in the oxycombustion unit (O) and at least part of the ammonia produced in the ammonia synthesis unit (N) as raw materials.
(canceled)
Dependencies are inferred from the claim text.