Patent US3594987A successfully refreshed from Google Patents.
US3594987A
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Method of recovering ammonia gas from aqueous solution containing ammonia and carbon dioxide
Assignee: Nippon Shokubai Co Ltd
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Filing: 1964-09-28
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Granted: 1971-07-27
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Expires: 1984-09-28
Abstract
Abstract A process for recovering ammonia gas from an aqueous solution containing ammonia and carbon dioxide which comprises countercurrently contacting such aqueous solution with a desorption gas selected from air, oxygen, nitrogen and mixtures thereof. The molar ratio of ammonia to carbon dioxide in the aqueous solution is at least 2, such aqueous solution being one obtained upon the synthesis of urea from ammonia and carbon dioxide or from the production of an aromatic nitrile by the ammoxidation of an aromatic hydrocarbon.
Inventors
- 👤 Kenzo Oda
- 👤 Takashi Ohara
- 👤 Kazuhide Sato
- 👤 Takashi Mori
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:38
CPC Classifications
C; C07; C07C; C07C273/00; C07C273/02; C07C273/04; C01; C01C; C01C1/00; C01C1/02; C01C1/10
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
98 words
A method of recovering ammonia gas from an aqueous solution containing ammonia and carbon dioxide in a molar ratio of ammonia to carbon dioxide of from 2:1 to 12.25:1, said aqueous solution being obtained upon synthesis of urea from ammonia and carbon dioxide, which method comprises concurrently contacting said aqueous solution with a desorption gas selected from the group consisting of air, oxygen, nitrogen and mixtures thereof, at a temperature below about 60* C. and above the freezing point of said aqueous solution, thereby desorbing from said aqueous solution ammonia gas which is substantially free of carbon dioxide.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-07-26 | 1975-01-25 | 1975-07-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-26 | 1979-01-25 | 1979-07-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-26 | 1983-01-25 | 1983-07-27 | $7700.00 | Window Closed / Lapsed |