Patent US2394627A successfully refreshed from Google Patents.
Patent US3856871A successfully refreshed from Google Patents.
US3856871A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Xylene isomerization
Assignee: Mobil Oil AS
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Filing: 1973-09-13
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Granted: 1974-12-24
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Expires: 1993-09-13
Abstract
Abstract Mixtures of C8 aromatic hydrocarbons are contacted in liquid phase with acid zeolite ZSM-5, zeolite ZSM-12 or ZSM-21. The xylene content is thereby isomerized and the ethyl benzene content of the charge is converted in a manner which facilitates separation of the conversion products from the stream of isomerization products.
Inventors
- 👤 W Haag
- 👤 D Olson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 06:17
CPC Classifications
B; B01; B01J; B01J29/00; B01J29/04; B01J29/06; B01J29/70; B01J29/7034; B01J29/40; C; C07; C07C; C07C5/00; C07C5/22; C07C5/27; C07C5/2702; C07C5/2708; C07C5/2729; C07C5/2732; C07C5/2737; B01J2229/00; B01J2229/10; B01J2229/26; B01J2229/30; B01J2229/42; Y; Y02; Y02P; Y02P20/00; Y02P20/50; Y02P20/52
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
100 words
IN A PROCESS FOR CONVERSION OF A MIXTURE OF AROMATIC COMPOUNDS HAVING 8 CARBON ATOMS, SAID MIXTURE CONTAINING ETHYL BENZENE AND XYLENES TO ISOMERIZE XYLENES CONTAINED IN SAID MIXTURE AND CONVERT AT LEAST PART OF ETHYL BENZENE SO CONTAINED TO COMPOUNDS READILY SEPARABLE BY DISTILLATION FROM 8 CARBON ATOM AROMATICS; THE IMPROVEMENT WHICH COMPRISES CONTAINING SUCH MIXTURE OF EIGHT CARBON ATOM AROMATIC COMPOUNDS WITH A CATALYST WHICH COMPRISES ACID ZEOLITE OF THE ZSM-5 TYPE, ACID ZEOLITE ZSM-12 OR ACID ZEOLITE ZSM-21 IN LIQUID PHASE AND IN THE ABSENCE OF ADDED HYDROGEN AT A TEMPERATURE OF ABOUT 500*F. TO ABOUT 660*F.
Claim 2
Dependent Claim
100 words
IN A PROCESS FOR CONVERSION OF A MIXTURE OF AROMATIC COMPOUNDS HAVING 8 CARBON ATOMS, SAID MIXTURE CONTAINING ETHYL BENZENE AND XYLENES TO ISOMERIZE XYLENES CONTAINED IN SAID MIXTURE AND CONVERT AT LEAST PART OF ETHYL BENZENE SO CONTAINED TO COMPOUNDS READILY SEPARABLE BY DISTILLATION FROM 8 CARBON ATOM AROMATICS; THE IMPROVEMENT WHICH COMPRISES CONTAINING SUCH MIXTURE OF EIGHT CARBON ATOM AROMATIC COMPOUNDS WITH A CATALYST WHICH COMPRISES ACID ZEOLITE OF THE ZSM-5 TYPE, ACID ZEOLITE ZSM-12 OR ACID ZEOLITE ZSM-21 IN LIQUID PHASE AND IN THE ABSENCE OF ADDED HYDROGEN AT A TEMPERATURE OF ABOUT 500*F. TO ABOUT 660*F.
Claim 3
Dependent Claim
130 words
A process for manufacture of p-xylene from a feed stream of C8 aromatics containing xylenes and ethyl benzene which coMprises mixing said feed stream with recycle xylenes derived as hereinafter recited, separating p-xylene from the mixture to provide product p-xylene and a C8 aromatic stream lean in p-xylene, subjecting said lean stream to contact with a catalyst which comprises acid zeolite of the ZSM-5 type, acid zeolite ZSM-12 or acid zeolite ZSM-21 in liquid phase and in the absence of added hydrogen at a temperature of about 500*F. to about 660*F., recycling the product of said contacting as recycle xylenes, mixing as aforesaid to provide a p-xylene recovery loop, and maintaining in said loop a concentration of ethyl benzene greater than the concentration of ethyl benzene in said feed stream.
Claim 4
Dependent Claim
130 words
A process for manufacture of p-xylene from a feed stream of C8 aromatics containing xylenes and ethyl benzene which coMprises mixing said feed stream with recycle xylenes derived as hereinafter recited, separating p-xylene from the mixture to provide product p-xylene and a C8 aromatic stream lean in p-xylene, subjecting said lean stream to contact with a catalyst which comprises acid zeolite of the ZSM-5 type, acid zeolite ZSM-12 or acid zeolite ZSM-21 in liquid phase and in the absence of added hydrogen at a temperature of about 500*F. to about 660*F., recycling the product of said contacting as recycle xylenes, mixing as aforesaid to provide a p-xylene recovery loop, and maintaining in said loop a concentration of ethyl benzene greater than the concentration of ethyl benzene in said feed stream.
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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) | 1977-12-23 | 1978-06-24 | 1978-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-23 | 1982-06-24 | 1982-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-23 | 1986-06-24 | 1986-12-24 | $7700.00 | Window Closed / Lapsed |