Patent US3675434A successfully refreshed from Google Patents.
US3675434A
Expired / Lapsed
US
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Separation of low-boiling gas mixtures
Assignee: MW Kellogg Co
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Filing: 1970-02-27
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Granted: 1972-07-11
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Expires: 1990-02-27
Abstract
Abstract A process for the recovery of hydrogen from an ammonia synthesis purge gas comprising ammonia, hydrogen, nitrogen and methane wherein ammonia is first separated from the purge gas and the gas substantially free of ammonia is subsequently cooled to very low temperatures, e.g., -300*F., thereby obtaining a liquid phase and a hydrogen-rich gaseous phase.
Inventors
- 👤 Duffer B Crawford
- 👤 Johannes C Norenburg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 10:52
CPC Classifications
F; F25; F25J; F25J3/00; F25J3/02; F25J3/0228; F25J3/0257; C; C01; C01B; C01B3/00; C01B3/50; C01B3/506; C01C; C01C1/00; C01C1/02; C01C1/04; C01C1/0405; C01C1/0476; F25J3/0204; F25J3/0219; F25J3/0233; F25J3/0252; F25J3/028; F25J3/0285; C01B2203/00; C01B2203/04; C01B2203/0465; C01B2203/048; F25J2200/00; F25J2200/08; F25J2200/72; F25J2200/76; F25J2205/00; F25J2205/02; F25J2205/04; F25J2210/00; F25J2210/06; F25J2210/20; F25J2215/00; F25J2215/04; F25J2270/00; F25J2270/02; F25J2270/04; Y; Y02; Y02P; Y02P20/00; Y02P20/50; Y02P20/52
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
44 words
A process according to claim 1 in which at least a major portion of the ammonia removal from the purge gas stream is accomplished by indirect heat exchange of the purge gas with at least one colder process stream to obtain an ammonia condensate.
Claim 2
Dependent Claim
47 words
A process according to claim 1 in which a hydrogen-rich gas taken from the group consisting of said uncondensed high pressure gas and said lower pressure flash gas is employed as the colder process stream in the indirect heat exchange step to partially condense the ammonia-free gas.
Claim 3
Dependent Claim
53 words
A Process according to claim 1 in which the following additional steps are undertaken comprising: heating said uncondensed high pressure gas rich in hydrogen by indirect heat exchange with condensing ammonia-free gas, expanding at least a portion of said heated gas rich in hydrogen, and introducing the expanded gas to said flash zone.
Claim 4
Dependent Claim
44 words
A process according to claim 2, in which a hydrogen-rich gas taken from the group consisting of said uncondensed high pressure gas and said lower pressure flash gas is employed in the indirect heat exchange of the purge gas to obtain an ammonia condensate.
References Cited (Backward Citations)
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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) | 1975-07-11 | 1976-01-10 | 1976-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-11 | 1980-01-10 | 1980-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-11 | 1984-01-10 | 1984-07-11 | $7700.00 | Window Closed / Lapsed |