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US 9,428,449 B2Granted
Method of forming urea by integration of an ammonia production process in a urea production process and a system therefor
AssigneeALSTOM Technology Ltd
InventorsFrank Ennenbach, Ulrich Koss
Life of this patent
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Abstract
A method of forming urea by integration of an ammonia production process with that of a urea production process, as well as a system for the method is disclosed. Also, an alternative method of forming urea by integration of a part of an ammonia production process with that of a urea production process, as well as a system for the alternative method.
Claims20
A method of forming urea by integration of an ammonia production process in a urea production process comprising:
- obtaining ammonia and carbon dioxide and a flue gas for a first ammonia stream, a carbon dioxide stream, and a flue gas stream containing carbon dioxide;
- separating the first ammonia stream into a second ammonia stream and a third ammonia stream, wherein the second ammonia stream is transported to an absorber and the third ammonia stream is transported to a urea synthesis section of the urea production process for the production of urea;
- transporting the carbon dioxide stream to the urea synthesis section;
- transporting the flue gas stream to the absorber;
- combining the second ammonia stream and a lean solvent stream provided from the urea production process to form a mixed stream;
- contacting the mixed stream with the flue gas stream in the absorber to absorb carbon dioxide from the flue gas stream to form a rich solvent stream and a treated gas stream;
- transporting the rich solvent stream emitted from the absorber to the urea synthesis section;
- contacting the carbon dioxide stream, the third ammonia stream and the rich solvent stream in the urea synthesis section to form urea and the lean solvent stream;
- and
- transporting the lean solvent stream from the urea production process to the absorber.
7 more elements
A method of forming urea by integration of a part of an ammonia production process in a urea production process, comprising:
- obtaining a hydrogen/carbon dioxide stream from the ammonia production process, and a flue gas stream containing carbon dioxide and nitrogen;
- transporting the flue gas stream to a low pressure absorber;
- contacting the flue gas stream with a lean solvent stream provided from the urea production process in the low pressure absorber to produce a semi-rich solvent stream and a cleaned gas stream containing nitrogen;
- transporting the hydrogen/carbon dioxide stream to a high pressure absorber;
- transporting the semi-rich solvent stream from the low pressure absorber to the high pressure absorber;
- contacting the hydrogen/carbon dioxide stream with the semi-rich solvent stream in the high pressure absorber to form a rich solvent stream and a hydrogen stream;
- transporting the rich solvent stream from the high pressure absorber to the urea production process to form urea and the lean solvent stream comprising a solution of carbamate, ammonia, carbon dioxide and water;
- transporting the lean solvent stream to the low pressure absorber, and
- transporting a stream from an ammonia production unit to the urea production process.
6 more elements
Dependencies are inferred from the claim text.