US4002697A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Selective production of para-xylene
Assignee: Mobil Oil AS
•
Filing: 1974-09-25
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Granted: 1977-01-11
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Expires: 1994-09-25
Abstract
Abstract Process for the selective production of para-xylene by methylation of toluene in the presence of a catalyst comprising a crystalline aluminosilicate of average crystal size greater than 0.5 micron, which aluminosilicate has the structure of ZSM-5, ZSM-11 or ZSM-21.
Inventors
- 👤 Nai Yuen Chen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:09
CPC Classifications
C; C07; C07C; C07C2/00; C07C2/86; C07C2/862; C07C2/865; C07C2/861; C07C2/864; C07C2/868; B; B01; B01J; B01J2229/00; B01J2229/10; B01J2229/12; B01J2229/30; B01J2229/32; C07C2529/00; C07C2529/04; C07C2529/06; C07C2529/40; C07C2529/65
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
98 words
In a process for manufacture of xylene by reacting toluene with a methylating agent in the presence of a crystalline aluminosilicate catalyst, the improvement resulting in a proportion of p-xylene greater than the thermo dynamic equilibrium proportion of total xylenes which comprises conducting the reaction in the presence of catalyst particles of ZSM-5, ZSM-11 or ZSM-21 of average crystal size greater than 0.5 micron, said catalyst particles having been surface deactivated by reaction with a compound of nitrogen or silicon of a size sufficiently large as to be unable to penetrate the pore structure of said crystalline aluminosilicate.
Claim 2
Dependent Claim
98 words
In a process for manufacture of xylene by reacting toluene with a methylating agent in the presence of a crystalline aluminosilicate catalyst, the improvement resulting in a proportion of p-xylene greater than the thermo dynamic equilibrium proportion of total xylenes which comprises conducting the reaction in the presence of catalyst particles of ZSM-5, ZSM-11 or ZSM-21 of average crystal size greater than 0.5 micron, said catalyst particles having been surface deactivated by reaction with a compound of nitrogen or silicon of a size sufficiently large as to be unable to penetrate the pore structure of said crystalline aluminosilicate.
Claim 3
Dependent Claim
16 words
The process of claim 1 wherein said methylating agent is methanol, methylchloride, methylbromide, dimethylether or dimethylsulfide.
Claim 4
Dependent Claim
19 words
The process of claim 1 wherein said crystal size is in the approximate range of 0.5 to 10 microns.
Claim 5
Dependent Claim
19 words
The process of claim 1 wherein said crystal size is within the approximate range of 1 to 8 microns.
Claim 6
Dependent Claim
31 words
The process of claim 1 wherein the surface of said catalyst has been modified by silylation with a silane incapable of entering the pores of said crystalline aluminosilicate followed by calcination.
Claim 7
Dependent Claim
10 words
The process of claim 5 wherein said silane is dimethyldichlorosilane.
Claim 8
Dependent Claim
22 words
The process of claim 5 wherein said calcination is carried out at a temperature between about 300° C. and about 700° C.
Claim 9
Dependent Claim
12 words
The process of claim 1 wherein said nitrogen compound is phenyl carbazole.
Claim 10
Dependent Claim
68 words
The process of claim 1 wherein the step of reacting toluene with a methylating agent is carried out at a temperature between about 300° C. and about 700° C., a pressure of between about 1 atmosphere and about 1000 psig, a weight hourly space velocity of between about 0.5 and about 10 employing a molar ratio of methylating agent to toluene of between about 0.5 and about 5.
Claim 11
Dependent Claim
42 words
The process of claim 5 wherein said silylation is effected at a temperature of between about 75° C. and about 200° C. the silane and zeolite being contacted on a weight basis of about 2 percent to about 200 percent of zeolite.
Claim 12
Dependent Claim
19 words
The process of claim 1 wherein said crystalline aluminosilicate is characterized by a silica/alumina ratio in excess of 30.
Claim 13
Dependent Claim
12 words
The process of claim 1 wherein the crystalline aluminosilicate catalyst is ZSM-5.
Claim 14
Dependent Claim
11 words
The process of claim 1 wherein the crystalline aluminosilicate is ZSM-11.
Claim 15
Dependent Claim
11 words
The process of claim 1 wherein the crystalline aluminosilicate is ZSM-21.
Claim 16
Dependent Claim
12 words
The process of claim 5 wherein the crystalline aluminosilicate catalyst is ZSM-5.
References Cited (Backward Citations)
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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) | 1980-01-11 | 1980-07-12 | 1981-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-01-11 | 1984-07-12 | 1985-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-01-11 | 1988-07-12 | 1989-01-11 | $7700.00 | Window Closed / Lapsed |