US4163028A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Xylene isomerization
Assignee: Mobil Oil AS
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Filing: 1978-06-05
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Granted: 1979-07-31
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Expires: 1998-06-05
Abstract
Abstract Isomerization of xylenes in admixture with ethyl benzene by contact with a zeolite catalyst such as ZSM-5 is improved by use of zeolite having a silica/alumina ratio of at least 500 at a temperature above about 800° F. At these conditions, conversion of ethyl benzene follows a different reaction path which permits high conversion of ethyl benzene to benzene without loss of xylenes by disproportionation.
Inventors
- 👤 Samuel A. Tabak
- 👤 Roger A. Morrison
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:24
CPC Classifications
B; B01; B01J; B01J29/00; B01J29/04; B01J29/06; B01J29/40; B01J29/42; B01J29/46; B01J29/44; C; C07; C07C; C07C5/00; C07C5/22; C07C5/27; 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: 14
Claim 1
Independent Claim
90 words
In a process for isomerizing the xylene content of a charge mixture of eight carbon atom aromatic hydrocarbon compounds which mixture contains xylene and ethyl benzene by contact at conversion conditions with a catalyst comprising a zeolite having a silica/alumina ratio greater than 12 and a constraint index of 1 to 12, the improvement resulting in conversion of ethyl benzene to benzene which comprises using as said catalyst a zeolite having a silica/alumina ratio of at least 500 maintaining a conversion temperature of about 800° F. to about 1000° F.
Claim 2
Dependent Claim
90 words
In a process for isomerizing the xylene content of a charge mixture of eight carbon atom aromatic hydrocarbon compounds which mixture contains xylene and ethyl benzene by contact at conversion conditions with a catalyst comprising a zeolite having a silica/alumina ratio greater than 12 and a constraint index of 1 to 12, the improvement resulting in conversion of ethyl benzene to benzene which comprises using as said catalyst a zeolite having a silica/alumina ratio of at least 500 maintaining a conversion temperature of about 800° F. to about 1000° F.
Claim 3
Dependent Claim
12 words
A process according to claim 1 wherein said zeolite is ZSM-5 (ccM).
Claim 4
Dependent Claim
11 words
A process according to claim 1 wherein said zeolite is ZSM-5.
Claim 5
Dependent Claim
20 words
A process according to claim 1 wherein said catalyst also comprises a metal of Group VIII of the Periodic Table.
Claim 6
Dependent Claim
12 words
A process according to claim 4 wherein said zeolite is ZSM-5 (ccPt).
Claim 7
Dependent Claim
11 words
A process according to claim 4 wherein said zeolite is ZSM-5.
Claim 8
Dependent Claim
14 words
A process according to claim 4 wherein said charge mixture is admixed with hydrogen.
Claim 9
Dependent Claim
12 words
A process according to claim 7 wherein said zeolite is ZSM-5 (ccM).
Claim 10
Dependent Claim
11 words
A process according to claim 7 wherein said zeolite is ZSM-5.
Claim 11
Dependent Claim
13 words
A process according to claim 1 wherein the reaction temperature is 800°-1000° F.
Claim 12
Dependent Claim
28 words
A process according to claim 1 resulting in conversion of ethyl benzene to benzene at substantially no loss of xylene in the product as compared to the charge.
Claim 13
Dependent Claim
14 words
A process according to claim 1 wherein the said charge mixture contains paraffin hydrocarbons.
Claim 14
Dependent Claim
16 words
A process according to claim 1 wherein the said charge mixture consists essentially of aromatic hydrocarbons.
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) | 1982-07-30 | 1983-01-29 | 1983-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-07-30 | 1987-01-29 | 1987-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-07-30 | 1991-01-29 | 1991-07-31 | $7700.00 | Window Closed / Lapsed |