Patent US4834956A successfully refreshed from Google Patents.
US4834956A
Expired / Lapsed
US
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Process for the production of high purity argon
Assignee: Air Products and Chemicals Inc
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Filing: 1987-03-30
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Granted: 1989-05-30
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Expires: 2007-03-30
Abstract
Abstract The present invention is a process for producing a high-purity argon stream from a feed gas containing nitrogen, oxygen and at least 85 mole % argon, Nitrogen is absorbed from the stream followed by catalytic hydrogenation to remove oxygen. The absorption column is regenerated at a preset low pressure using the nitrogen-depleted stream from the absorption unit as the purge gas.
Inventors
- 👤 Rakesh Agrawal
- 👤 Steven R. Auvil
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 21:23
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/02; B01D53/04; B01D53/047; B01D53/0476; C; C01; C01B; C01B23/00; B01D2253/00; B01D2253/10; B01D2253/106; B01D2253/108; B01D2256/00; B01D2256/18; B01D2257/00; B01D2257/10; B01D2257/102; B01D2259/00; B01D2259/40; B01D2259/40001; B01D2259/40011; B01D2259/40043; B01D2259/4005; B01D2259/40052; B01D2259/40058; B01D2259/40062; B01D2259/403; B01D2259/416
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
151 words
A process for purifying crude argon feed gas containing nitrogen, oxygen and at least 85 mole % argon which comprises the steps of: a) passing said feed gas to an adsorption column containing an adsorbent for selectively adsorbing nitrogen to produce a nitrogen-lean stream containing oxygen and argon; b) subsequently reducing the pressure of said adsorption column to between 300 and 20 torr, thereby causing evacuation of the column; c) pruging the evacuated column using a portion of the nitrogen-lean stream; d) mixing the remainder of the nitrogen-lean stream with a stoichiometric quantity of hydrogen relative to oxygen and subsequently passing the resultant stream over a suitable catalyst to form water; and e) removing said water from the nitrogen-lean stream to produce a purified argon stream; whereby removal of oxygen from the nitrogen-lean stream of step a) is effected entirely by passing the resultant stream over the catalyst of step d).
Claim 2
Dependent Claim
151 words
A process for purifying crude argon feed gas containing nitrogen, oxygen and at least 85 mole % argon which comprises the steps of: a) passing said feed gas to an adsorption column containing an adsorbent for selectively adsorbing nitrogen to produce a nitrogen-lean stream containing oxygen and argon; b) subsequently reducing the pressure of said adsorption column to between 300 and 20 torr, thereby causing evacuation of the column; c) pruging the evacuated column using a portion of the nitrogen-lean stream; d) mixing the remainder of the nitrogen-lean stream with a stoichiometric quantity of hydrogen relative to oxygen and subsequently passing the resultant stream over a suitable catalyst to form water; and e) removing said water from the nitrogen-lean stream to produce a purified argon stream; whereby removal of oxygen from the nitrogen-lean stream of step a) is effected entirely by passing the resultant stream over the catalyst of step d).
Claim 3
Dependent Claim
24 words
A process in accordance with claim 1 wherein said argon stream of enhanced purity has an argon concentration of at least 99 mole %.
Claim 4
Dependent Claim
17 words
A process in accordance with claim 1 wherein said adsorbent is an ion exchanged aluminosilicate molecular sieve.
Claim 5
Dependent Claim
22 words
A process in accordance with claim 1 wherein said feed gas contains between 2-10 mole % oxygen and 0.01-5 mole % nitrogen.
Claim 6
Dependent Claim
30 words
A process in accordance with claim 3 wherein said adsorption is carried out at a pressure between about 1-2 atmospheres and at a temperature between -20° C. to 30° C.
Claim 7
Dependent Claim
19 words
A process in accordance with claim 1 wherein said feed gas is generated by a cryogenic air separation plant.
Claim 8
Dependent Claim
22 words
A process in accordance with claim 6 wherein the purge from the adsorption column is recycled to the cryogenic air separation plant.
Claim 9
Dependent Claim
17 words
A process in accordance with claim 1 wherein two or more adsorption columns in parallel as used.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-05-29 | 1992-11-28 | 1993-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-29 | 1996-11-28 | 1997-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-29 | 2000-11-28 | 2001-05-30 | $7700.00 | Window Closed / Lapsed |