Patent US3066997A successfully refreshed from Google Patents.
Patent US5152813A successfully refreshed from Google Patents.
US5152813A
Expired / Lapsed
US
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Nitrogen adsorption with a Ca and/or Sr exchanged lithium X-zeolite
Assignee: Air Products and Chemicals Inc
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Filing: 1991-12-20
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Granted: 1992-10-06
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Expires: 2011-12-20
Abstract
Abstract The present invention is directed to a process for separating nitrogen from gas mixtures containing nitrogen and less strongly adsorbed components such as oxygen, hydrogen, argon or helium by use of an at least binary exchanged X-zeolite having lithium and calcium and/or strontium ions in ratio of preferably 5% to 50% calcium and/or strontium and 50% to 95% lithium.
Inventors
- 👤 Charles G. Coe
- 👤 John F. Kirner
- 👤 Ronald Pierantozzi
- 👤 Thomas R. White
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:36
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/02; B01D53/04; B01J; B01J20/00; B01J20/02; B01J20/10; B01J20/16; B01J20/18; B01J20/186; C; C01; C01B; C01B13/00; C01B13/02; C01B13/0229; C01B13/0248; C01B13/0259; C01B13/0262; C01B13/027; C01B21/00; C01B21/04; C01B21/0405; C01B21/0433; C01B21/045; C01B21/0455; C01B21/0466; B01D2253/00; B01D2253/10; B01D2253/106; B01D2253/108; B01D2253/1085; B01D2256/00; B01D2256/12; B01D2257/00; B01D2257/10; B01D2257/102; B01D2257/11; C01B2210/00; C01B2210/0043; C01B2210/0046; Y; Y10; Y10S; Y10S95/00; Y10S95/90; Y10S95/902
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
130 words
A process for selectively adsorbing nitrogen from a gas mixture containing nitrogen and at least one less strongly adsorbed component which comprises contacting the gas mixture with a zone of an adsorbent which is selective for the adsorption of nitrogen, selectively adsorbing nitrogen on the adsorbent and passing the gas mixture less the adsorbed nitrogen out of the zone, wherein the adsorbent comprises a crystalline X-zeolite having a zeolitic Si/Al ratio≦1.5 and an at least binary ion exchange of the exchangeable ion content with between 5% and 95% lithium and with between 5% and 95% of a second ion selected from the group consisting of calcium, strontium and mixtures thereof, wherein the sum of the lithium and second ion ion exchange is at least 60% of the exchangeable ion content.
Claim 2
Dependent Claim
130 words
A process for selectively adsorbing nitrogen from a gas mixture containing nitrogen and at least one less strongly adsorbed component which comprises contacting the gas mixture with a zone of an adsorbent which is selective for the adsorption of nitrogen, selectively adsorbing nitrogen on the adsorbent and passing the gas mixture less the adsorbed nitrogen out of the zone, wherein the adsorbent comprises a crystalline X-zeolite having a zeolitic Si/Al ratio≦1.5 and an at least binary ion exchange of the exchangeable ion content with between 5% and 95% lithium and with between 5% and 95% of a second ion selected from the group consisting of calcium, strontium and mixtures thereof, wherein the sum of the lithium and second ion ion exchange is at least 60% of the exchangeable ion content.
Claim 3
Dependent Claim
18 words
The process of claim 1 wherein the zeolite is ion exchanged with lithium to approximately 50% to 95%.
Claim 4
Dependent Claim
20 words
The process of claim 1 wherein the zeolite is ion exchanged with the second ion to approximately 5% to 50%.
Claim 5
Dependent Claim
21 words
The process of claim 1 wherein the zeolite is ion exchanged with approximately 15% of the second ion and 85% lithium.
Claim 6
Dependent Claim
11 words
The process of claim 1 wherein the second ion is calcium.
Claim 7
Dependent Claim
11 words
The process of claim 1 wherein the second ion is strontium.
Claim 8
Dependent Claim
18 words
The process of claim 1 wherein the zeolite is ion exchanged with approximately 15% calcium and 85% lithium.
Claim 9
Dependent Claim
13 words
The process of claim 1 wherein the gas mixture contains nitrogen and oxygen.
Claim 10
Dependent Claim
11 words
The process of claim 1 wherein the gas mixture is air.
Claim 11
Dependent Claim
12 words
The process of claim 1 wherein the Si/Al ratio is approximately 1.
Claim 12
Dependent Claim
39 words
The process of claim 1 wherein an oxygen and nitrogen containing gas mixture contacts a zone of said adsorbent, the nitrogen is selectively adsorbed and the oxygen passes through the zone and is recovered as an oxygen enriched product.
Claim 13
Dependent Claim
18 words
The process of claim 11 wherein the oxygen product has a purity of at least approximately 90% oxygen.
Claim 14
Dependent Claim
24 words
The process of claim 11 wherein the adsorption is conducted at an average bed temperature in the range of approximately 55 to 135° F.
Claim 15
Dependent Claim
67 words
The process of claim 11 wherein the zone is operated through a series of steps comprising: adsorption during which the gas mixture contacts the adsorbent, nitrogen is selectively adsorbed and oxygen passes through the zone as a product; depressurization during which the gas mixture contact is discontinued and the zone is reduced in pressure to desorb the nitrogen; and repressurization with oxygen product to the adsorption pressure.
Claim 16
Dependent Claim
19 words
The process of claim 14 wherein the adsorption pressure is in the range of approximately 35 to 65 psia.
Claim 17
Dependent Claim
23 words
The process of claim 14 wherein the desorption is conducted down to a pressure in the range of approximately 14.7 to 16.7 psia.
Claim 18
Dependent Claim
77 words
The process of claim 11 wherein the zone is operated through a series of steps comprising: adsorption during which the gas mixture contacts the adsorbent, nitrogen is selectively adsorbed and oxygen passes through the zone as a product; depressurization during which the gas mixture 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 product to the adsorption pressure.
Claim 19
Dependent Claim
19 words
The process of claim 17 wherein the adsorption pressure is in the range of approximately 900 to 1600 torr.
Claim 20
Dependent Claim
23 words
The process of claim 17 wherein the evacuation is conducted down to a level in the range of approximately 80 to 400 torr.
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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) | 1995-10-06 | 1996-04-06 | 1996-10-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-10-06 | 2000-04-06 | 2000-10-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-10-06 | 2004-04-06 | 2004-10-06 | $7700.00 | Window Closed / Lapsed |