US4544378A
Expired / Lapsed
US
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Nitrogen adsorption process
Assignee: Air Products and Chemicals Inc
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Filing: 1984-05-24
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Granted: 1985-10-01
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Expires: 2004-05-24
Abstract
Abstract The invention relates to a process for adsorption of nitrogen from nitrogen-containing gases using faujasite-containing compositions in which the original hydrogen or monovalent forms are ion exchanged to their polyvalent form and then dehydrated in such a manner as to result in a preponderence of its polyvalent ions in a dehydrated/dehydroxylated state while maintaining substantially the same zeolite content. The resulting compositions, whose cations contained in the faujasitic portion are substantially in their dehydrated/dehydroxylated state, have been found to have surprisingly high selectivities and capacities for the separation of air into nitrogen and oxygen.
Inventors
- 👤 Charles G. Coe
- 👤 Steven M. Kuznicki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:45
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/02; B01D53/04; B01D53/0454; B01J; B01J20/00; B01J20/02; B01J20/10; B01J20/16; B01J20/18; B01J20/186; C; C01; C01B; C01B13/00; C01B13/02; B01D2253/00; B01D2253/10; B01D2253/106; B01D2253/108; B01D2253/1085; B01D2256/00; B01D2256/10; B01D2256/12; B01D2257/00; B01D2257/10; B01D2257/102; B01D2257/104; Y; Y10; Y10S; Y10S95/00; Y10S95/90; Y10S95/902
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
115 words
In a process for the adsorption of nitrogen from nitrogen-containing gases, the improvement which comprises contacting said nitrogen-containing gases with a polyvalent cation exchanged zeolitic adsorbent containing at least 50% by weight faujasite and the faujasite portion thereof having a majority of its exchangeable cations present in the polyvalent cation exchanged form, said adsorbent having been dehydrated in such a manner as to minimize the amount of water in the gaseous environment in contact with said adsorbent during this dehydration step to a partial pressure of water of less than about 0.4 atmospheres at temperatures above 150° up to about 650° C. thereby resulting in a preponderance of its polyvalent ions in a dehydrated/dehydroxylated state.
Claim 2
Dependent Claim
115 words
In a process for the adsorption of nitrogen from nitrogen-containing gases, the improvement which comprises contacting said nitrogen-containing gases with a polyvalent cation exchanged zeolitic adsorbent containing at least 50% by weight faujasite and the faujasite portion thereof having a majority of its exchangeable cations present in the polyvalent cation exchanged form, said adsorbent having been dehydrated in such a manner as to minimize the amount of water in the gaseous environment in contact with said adsorbent during this dehydration step to a partial pressure of water of less than about 0.4 atmospheres at temperatures above 150° up to about 650° C. thereby resulting in a preponderance of its polyvalent ions in a dehydrated/dehydroxylated state.
Claim 3
Dependent Claim
14 words
The process of claim 1 for the separation of air into nitrogen and oxygen.
Claim 4
Dependent Claim
17 words
The process of claim 1 for the adsorption of nitrogen from a mixture of gases containing nitrogen.
Claim 5
Dependent Claim
24 words
The process of claim 1 wherein said faujasite has a silicon to aluminum ratio in the range of approximately 1 up to about 2.
Claim 6
Dependent Claim
11 words
The process of claim 1 wherein said faujasite is an X-type.
Claim 7
Dependent Claim
46 words
The process of claim 1 wherein said adsorbent contains at least 75% by weight of an X-type of faujasite and the balance is an adsorbent selected from the group consisting of an A-type of zeolite, an inert clay binder, other inert solid materials and mixtures thereof.
Claim 8
Dependent Claim
12 words
The process of claim 6 wherein said polyvalent cations are calcium ions.
Claim 9
Dependent Claim
11 words
The process of claim 1 wherein said polyvalent cations are divalent.
Claim 10
Dependent Claim
23 words
The process of claim 1 wherein said polyvalent cations are selected from a group consisting of magnesium, calcium, strontium, barium, and mixtures thereof.
Claim 11
Dependent Claim
12 words
The process of claim 1 wherein said polyvalent cations are calcium ions.
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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) | 1988-09-30 | 1989-04-01 | 1989-10-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-09-30 | 1993-04-01 | 1993-10-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-09-30 | 1997-04-01 | 1997-10-01 | $7700.00 | Window Closed / Lapsed |