US4415481A
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Pyridine-modified Na X-type or Li X-type adsorbent characterized by its ability to separate para-xylene from C-8 aromatic hydrocarbon mixtures
Assignee: Texaco Inc
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Filing: 1982-06-14
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Granted: 1983-11-15
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Expires: 2002-06-14
Abstract
Abstract Para-xylene may be separated as front-end product in high purity by contacting charge C-8 aromatic hydrocarbon mixture with NaX-type or LiX-type zeolite in the presence of a pyridine.
Inventors
- 👤 William Smolin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 06:08
CPC Classifications
B; B01; B01J; B01J29/00; B01J29/04; B01J29/06; B01J29/08; B01J29/082; C; C07; C07C; C07C7/00; C07C7/12; C07C7/13; Y; Y02; Y02P; Y02P20/00; Y02P20/50; Y02P20/52
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
34 words
An adsorbent, characterized by its ability to separate high purity para-xylene from feed mixtures containing C-8 aromatic hydrocarbon including para-xylene, which comprises a sodium X-type or a lithium X-type zeolite, modified with a pyridine.
Claim 2
Dependent Claim
34 words
An adsorbent, characterized by its ability to separate high purity para-xylene from feed mixtures containing C-8 aromatic hydrocarbon including para-xylene, which comprises a sodium X-type or a lithium X-type zeolite, modified with a pyridine.
Claim 3
Dependent Claim
44 words
An adsorbent, characterized by its ability to separate high purity para-xylene from feed mixtures containing C-8 aromatic hydrocarbon including para-xylene, which comprises a sodium-X-type zeolite or a lithium X-type zeolite modified with a pyridine in amount of 1-20 w % of the X-type zeolite.
Claim 4
Dependent Claim
44 words
An adsorbent, characterized by its ability to separate high purity para-xylene from feed mixtures containing C-8 aromatic hydrocarbon including para-xylene, which comprises a sodium-X-type zeolite or a lithium X-type zeolite modified with a pyridine in amount of 1-20 w % of the X-type zeolite.
Claim 5
Dependent Claim
32 words
An adsorbent, characterized by its ability to separate high purity para-xylene from feed mixtures containing C-8 aromatic hydrocarbon including para-xylene which comprises a high silica sodium X-type zeolite modified with a pyridine.
Claim 6
Dependent Claim
32 words
An adsorbent, characterized by its ability to separate high purity para-xylene from feed mixtures containing C-8 aromatic hydrocarbon including para-xylene which comprises a high silica sodium X-type zeolite modified with a pyridine.
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) | 1986-11-14 | 1987-05-16 | 1987-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-11-14 | 1991-05-16 | 1991-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-11-14 | 1995-05-16 | 1995-11-15 | $7700.00 | Window Closed / Lapsed |