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Patent US4152364A successfully refreshed from Google Patents.
US4152364A
Expired / Lapsed
US
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Selective production of para-xylene
Assignee: Mobil Oil AS
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Filing: 1978-01-19
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Granted: 1979-05-01
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Expires: 1998-01-19
Abstract
Abstract Process for the selective production of para-xylene by methylation of toluene in the presence of a catalyst comprising a crystalline aluminosilicate zeolite, said zeolite having 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, which catalyst has undergone prior modification by treatment with an ammonium hydrogen phosphate to deposit at least about 0.5 weight percent of phosphorus thereon.
Inventors
- 👤 Chin-Chiun Chu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:11
CPC Classifications
C; C07; C07C; C07C2/00; C07C2/86; C07C2/862; C07C2/865; B; B01; B01J; B01J29/00; B01J29/04; B01J29/06; B01J29/40; C07C2/861; C07C2/864; C07C2/868; B01J2229/00; B01J2229/10; B01J2229/26; B01J2229/30; B01J2229/42; C07C2529/00; C07C2529/04; C07C2529/06; C07C2529/40; Y; Y02; Y02P; Y02P20/00; Y02P20/50; Y02P20/52
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
78 words
A process for the selective production of para-xylene which comprises reacting toluene with a methylating agent under methylation conditions in the presence of a catalyst comprising a crystalline aluminosilicate zeolite, said zeolite having a silica to alumina ratio of at least about 12, a constraint index within the approximate range of 1 to 12, said catalyst having undergone prior modification by treatment with an ammonium hydrogen phosphate to deposit at least about 0.5 weight percent of phosphorus thereon.
Claim 2
Dependent Claim
78 words
A process for the selective production of para-xylene which comprises reacting toluene with a methylating agent under methylation conditions in the presence of a catalyst comprising a crystalline aluminosilicate zeolite, said zeolite having a silica to alumina ratio of at least about 12, a constraint index within the approximate range of 1 to 12, said catalyst having undergone prior modification by treatment with an ammonium hydrogen phosphate to deposit at least about 0.5 weight percent of phosphorus thereon.
Claim 3
Dependent Claim
18 words
The process of claim 1 wherein said methylating agent is methanol, methyl chloride, methyl bromide, dimethylether or dimethylsulfide.
Claim 4
Dependent Claim
14 words
The process of claim 1 wherein said ammonium hydrogen phosphate is diammonium hydrogen phosphate.
Claim 5
Dependent Claim
14 words
The process of claim 1 wherein said ammonium hydrogen phosphate is ammonium dihydrogen phosphate
Claim 6
Dependent Claim
11 words
The process of claim 1 wherein said crystalline aluminosilicate is ZSM-5.
Claim 7
Dependent Claim
58 words
The process of claim 1 wherein said methylation conditions include a temperature between about 250° C. and about 750° C., a pressure within the approximate range of 1 atmosphere to 1000 psig, a weight hourly space velocity between about 1 and about 2000 and a molar ratio of methylating agent to toluene between about 0.05 and about 20.
Claim 8
Dependent Claim
17 words
The process of claim 6 wherein said temperature is between about 400° C. and about 700° C.
Claim 9
Dependent Claim
22 words
The process of claim 1 wherein said phosphorus is present in an amount of between about 0.5 and about 25 weight percent.
Claim 10
Dependent Claim
20 words
The process of claim 1 wherein said crystalline aluminosilicate zeolite is characterized by a silica/alumina ratio in excess of 30.
Claim 11
Dependent Claim
11 words
The process of claim 1 wherein said methylating agent is methanol.
References Cited (Backward Citations)
US3965208A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-04-30 | 1982-10-30 | 1983-05-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-04-30 | 1986-10-30 | 1987-05-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-04-30 | 1990-10-30 | 1991-05-01 | $7700.00 | Window Closed / Lapsed |