Patent US5266102A successfully refreshed from Google Patents.
US5266102A
Expired / Lapsed
US
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O2 VSA process with low O2 capacity adsorbents
Assignee: Air Products and Chemicals Inc
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Filing: 1992-09-23
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Granted: 1993-11-30
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Expires: 2012-09-23
Abstract
Abstract The invention is a process for selectively adsorbing nitrogen from a gas mixture which comprises contacting the gas mixture with an adsorbent that has a moderate nitrogen capacity and a high selectivity for nitrogen over the other components in the mixture. With respect to air separation, improved adsorbents have low O 2 capacity with N 2 capacity at roughly the same level as current adsorbents such as CaA. O 2 VSA computer process simulations have shown the unexpected result that for materials with the same binary isothermal working selectivity, those with lower isothermal nitrogen working capacity are superior O 2 VSA adsorbents, provided that they have a nitrogen working capacity of at least about 0.3 mmol/g.
Inventors
- 👤 Thomas R. Gaffney
- 👤 John F. Kirner
- 👤 Ravi Kumar
- 👤 Robin J. Maliszewskyj
- 👤 William P. Schmidt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 12:34
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/02; B01D53/04; B01D53/047; B01D53/0476; B01J; B01J20/00; B01J20/02; B01J20/10; B01J20/16; B01J20/18; B01J20/186; B01D2253/00; B01D2253/10; B01D2253/104; B01D2253/106; B01D2253/108; B01D2253/30; B01D2256/00; B01D2256/12; B01D2257/00; B01D2257/10; B01D2257/102
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
82 words
The process of adsorbing nitrogen from a gas containing nitrogen, comprising; contacting the gas in an adsorption zone with an adsorbent selective for nitrogen and adsorbing nitrogen on the adsorbent, wherein the adsorbent zone comprises an adsorbent with an isothermal nitrogen working capacity of at least about 0.3 mmol/g and a binary isothermal working selectivity of at least 17 mmol N 2 /mmol O 2 but whose nitrogen working capacity at any given working selectivity (S) does not exceed the value: 0.0667×(S)-0.667.
Claim 2
Dependent Claim
82 words
The process of adsorbing nitrogen from a gas containing nitrogen, comprising; contacting the gas in an adsorption zone with an adsorbent selective for nitrogen and adsorbing nitrogen on the adsorbent, wherein the adsorbent zone comprises an adsorbent with an isothermal nitrogen working capacity of at least about 0.3 mmol/g and a binary isothermal working selectivity of at least 17 mmol N 2 /mmol O 2 but whose nitrogen working capacity at any given working selectivity (S) does not exceed the value: 0.0667×(S)-0.667.
Claim 3
Dependent Claim
16 words
The process of claim 1, wherein the isothermal nitrogen working capacity is at least 0.4 mmol/g.
Claim 4
Dependent Claim
17 words
The process of claim 1 wherein the isothermal nitrogen working capacity is no greater than 1.0 mmol/g.
Claim 5
Dependent Claim
17 words
The process of claim 1 wherein the isothermal nitrogen working capacity is between 0.4 and 0.6 mmol/g.
Claim 6
Dependent Claim
18 words
The process of claim 1 wherein said adsorbent comprises an active adsorbent phase and optionally an inert diluent.
Claim 7
Dependent Claim
27 words
The process of claim 5 wherein said active adsorbent phase is selected from the group consisting of zeolite, silica-alumina, alumina, silica, titanium silicates, phosphates and mixtures thereof.
Claim 8
Dependent Claim
27 words
The process of claim 5 wherein said active adsorbent phase is a zeolite selected from the group consisting of A-zeolite, X-zeolite, Y-zeolite, chabazite, mordenite and mixtures thereof.
Claim 9
Dependent Claim
18 words
The process of claim 7 wherein the zeolite is ion exchanged with lithium to at least approximately 50%.
Claim 10
Dependent Claim
20 words
The process of claim 8 wherein the zeolite is ion exchanged with a second ion to approximately 5% to 50%.
Claim 11
Dependent Claim
21 words
The process of claim 9 wherein the zeolite is ion exchanged with approximately 15% of the second ion and 85% lithium.
Claim 12
Dependent Claim
21 words
The process of claim 9 wherein the second ion is selected from the group consisting of calcium, strontium and mixtures thereof.
Claim 13
Dependent Claim
18 words
The process of claim 11 wherein the zeolite is ion exchanged with approximately 15% calcium and 85% lithium.
Claim 14
Dependent Claim
23 words
The process of claim 5 wherein said active adsorbent phase has a zeolithic silicon to aluminum ratio less than or equal to 1.5.
Claim 15
Dependent Claim
12 words
The process of claim 1 wherein the gas contains nitrogen and oxygen.
Claim 16
Dependent Claim
10 words
The process of claim 1 wherein the gas is air.
Claim 17
Dependent Claim
34 words
The process of claim 1 wherein an oxygen and nitrogen-containing gas contacts said adsorbent zone, the nitrogen is selectively adsorbed and the oxygen passes through said zone and is recovered as an oxygen-enriched product.
Claim 18
Dependent Claim
18 words
The process of claim 16 wherein the oxygen product has a purity of at least approximately 90% oxygen.
Claim 19
Dependent Claim
69 words
The process of claim 16 wherein said zone is operated through a series of steps comprising: adsorption during which the gas contacts said active adsorbent phase, nitrogen is selectively adsorbed and oxygen passes through the zone and is removed; depressurization during which the gas contact is discontinued and the zone is reduced in pressure to desorb the nitrogen; and repressurization with oxygen or said gas to the adsorption pressure.
Claim 20
Dependent Claim
79 words
The process of claim 16 wherein said zone is operated through a series of steps comprising: adsorption during which the gas contacts said active adsorbent phase, nitrogen is selectively adsorbed and oxygen passes through the zone and is removed; depressurization during which the gas contact is discontinued and the zone is reduced in pressure to desorb the nitrogen; evacuation to further desorb the nitrogen to below ambient pressure; and repressurization with oxygen or said gas to the adsorption pressure.
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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) | 1996-11-29 | 1997-05-31 | 1997-11-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-11-29 | 2001-05-31 | 2001-11-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-11-29 | 2005-05-31 | 2005-11-30 | $7700.00 | Window Closed / Lapsed |