US4159282A
Expired / Lapsed
US
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Xylene isomerization
Assignee: Mobil Oil AS
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Filing: 1978-06-09
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Granted: 1979-06-26
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Expires: 1998-06-09
Abstract
Abstract {PG,1 A catalytic process is provided for isomerizing an isomerization feed containing an aromatic C{HD 8 {L mixture of ethylbenzene and xylene in which the para-xylene content is less than equilibrium which comprises contacting said feed, under conversion conditions, with a catalyst comprising a crystalline aluminosilicate zeolite having a crystal size of at least about 1 micron, a silica to alumina ratio of at least about 12 and a constraint index, as hereinafter defined, within the approximate range of 1 to 12 to yield an isomerization product characterized by a reduced ethylbenzene content and an enhanced para-xylene content.
Inventors
- 👤 David H. Olson
- 👤 Werner O. Haag
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 20:07
CPC Classifications
C; C07; C07C; C07C5/00; C07C5/22; C07C5/27; C07C5/2767; C07C5/277; C07C5/2775; Y; Y02; Y02P; Y02P20/00; Y02P20/50; Y02P20/52
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
90 words
A process for isomerizing an isomerization feed containing an aromatic C 8 mixture of ethylbenzene and xylene, in which the para-xylene content is less than equilibrium which comprises contacting said feed, under conversion conditions, with a catalyst comprising a crystalline aluminosilicate zeolite having a crystal size of at least about 1 micron, a silica to alumina ratio of at least about 12 and a constraint index within the approximate range of 1 to 12 to yield an isomerization product characterized by a reduced ethylbenzene content and an enhanced para-xylene content.
Claim 2
Dependent Claim
90 words
A process for isomerizing an isomerization feed containing an aromatic C 8 mixture of ethylbenzene and xylene, in which the para-xylene content is less than equilibrium which comprises contacting said feed, under conversion conditions, with a catalyst comprising a crystalline aluminosilicate zeolite having a crystal size of at least about 1 micron, a silica to alumina ratio of at least about 12 and a constraint index within the approximate range of 1 to 12 to yield an isomerization product characterized by a reduced ethylbenzene content and an enhanced para-xylene content.
Claim 3
Dependent Claim
43 words
The process of claim 1 wherein said conversion conditions include a temperature of from about 400° to about 1000° F., a pressure of from about 0 to about 1500 psig and a weight hourly space velocity of between about 0.5 and about 100.
Claim 4
Dependent Claim
43 words
The process of claim 1 wherein said conversion conditions include a temperature of from about 500° to about 950° F., a pressure of from about 25 to about 1000 psig and a weight hourly space velocity of between about 1 and about 50.
Claim 5
Dependent Claim
19 words
The process of claim 1 wherein said aromatic C 8 mixture consists essentially of ethylbenzene, para-xylene, meta-xylene and ortho-xylene.
Claim 6
Dependent Claim
24 words
The process of claim 1 wherein said isomerization feed contains said aromatic C 8 mixture and up to 30 weight percent of non-aromatic hydrocarbons.
Claim 7
Dependent Claim
12 words
The process of claim 1 wherein said crystalline aluminosilicate zeolite is ZSM-5.
Claim 8
Dependent Claim
17 words
The process of claim 1 wherein said crystalline aluminosilicate zeolite is ZSM-5 predominantly in the hydrogen form.
Claim 9
Dependent Claim
24 words
The process of claim 1 wherein the crystal size of said crystalline aluminosilicate zeolite is within the approximate range of 1 to 20 microns.
Claim 10
Dependent Claim
24 words
The process of claim 1 wherein the crystal size of said crystalline aluminosilicate zeolite is within the approximate range of 1 to 6 microns.
Claim 11
Dependent Claim
16 words
The process of claim 6 wherein the ZSM-5 is present in combination with a binder therefor.
Claim 12
Dependent Claim
61 words
The process of claim 1 wherein said crystalline aluminosilicate zeolite is characterized by a xylene sorption capacity greater than 1 gram/100 grams of zeolite and an ortho xylene sorption time for 30 percent of said capacity of greater than 10 minutes, said sorption capacity and sorption time being measured at 120° C. and a xylene pressure of 4.5±0.8 mm. of mercury.
Claim 13
Dependent Claim
25 words
The process of claim 1 wherein said crystalline aluminosilicate has combined therewith between about 0.5 and about 40 weight percent of a difficulty reducible oxide.
Claim 14
Dependent Claim
13 words
The process of claim 12 wherein said difficulty reducible oxide is magnesium oxide.
References Cited (Backward Citations)
US3856872A
Cited
US3856871A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-06-25 | 1982-12-25 | 1983-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-06-25 | 1986-12-25 | 1987-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-06-25 | 1990-12-25 | 1991-06-26 | $7700.00 | Window Closed / Lapsed |