US4490570A
Expired / Lapsed
US
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Method for para selective alkylation employing silicalite catalysts
Assignee: Cosden Technology Inc
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Filing: 1982-02-22
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Granted: 1984-12-25
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Expires: 2002-02-22
Abstract
Abstract A process for the selective alkylation of a monoalkyl benzene in which the alkyl substituent is either methyl or ethyl, to yield a dialkylbenzene product in which the para isomer of the disubstituted product is present in a concentration greater than in a thermodynamic equilibrium is provided. The method essentially comprises passing the monoalkyl benzene and an alkylating agent capable of methylation or ethylation through a reaction zone containing a crystalline silica polymorph silicalite catalyst. Water, in the form of steam, can be co-fed as an option.
Inventors
- 👤 Cleve H. Forward
- 👤 James R. Butler
- 👤 James M. Watson
- 👤 Gary D. Branum
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 17:49
CPC Classifications
C; C07; C07C; C07C2/00; C07C2/54; C07C2/64; C07C2/66; C07C2529/00; C07C2529/03; C07C2529/035
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
81 words
A process for the selective alkylation of a monoalkyl benzene in which the alkyl substituent is either methyl or ethyl, to yield a dialkyl benzene product in which the para isomer of the disubstituted product is present in a concentration greater than in a thermodynamic equilibrium, comprising: passing the monoalkyl benzene and an alkylating agent capable of methylation or ethylation under conversion conditions which do not include steam cofeed through a reaction zone containing an unmodified crystalline silica polymorph silicalite catalyst.
Claim 2
Dependent Claim
81 words
A process for the selective alkylation of a monoalkyl benzene in which the alkyl substituent is either methyl or ethyl, to yield a dialkyl benzene product in which the para isomer of the disubstituted product is present in a concentration greater than in a thermodynamic equilibrium, comprising: passing the monoalkyl benzene and an alkylating agent capable of methylation or ethylation under conversion conditions which do not include steam cofeed through a reaction zone containing an unmodified crystalline silica polymorph silicalite catalyst.
Claim 3
Dependent Claim
13 words
The process as recited in claim 1 wherein the alkylating agent is ethylene.
Claim 4
Dependent Claim
13 words
The process as recited in claim 1 wherein the monoalkyl benzene is toluene.
Claim 5
Dependent Claim
62 words
The method as recited in claim 1 wherein the conversion conditions comprise temperatures in the range of from about 300° C. to about 600° C., a molar feed ratio of monoalkyl benzene to alkylating agent between about 2:1 to about 20:1, a monoalkyl benzene WHSV ranging from about 50 to about 200 and pressures ranging from about atmospheric to about 25 atmospheres.
Claim 6
Dependent Claim
57 words
The process as recited in claim 4 wherein the temperature range is from about 350° C. to about 450° C., the molar feed ratio range is from about 7:1 to about 18:1, the pressure range is from about 11 atmospheres to about 13 atmospheres and the monoalkyl benzene WHSV range is from about 120 to about 200.
Claim 7
Dependent Claim
80 words
A process for producing dialkyl benzene products comprising: (a) introducing to a reaction zone containing a bed of a crystalline silica polymorph silicalite catalyst a monoalkyl benzene and an alkylating agent; (b) allowing said monoalkyl benzene and alkylating agent to come into contact with said silicalite catalyst material under conversion conditions which do not include steam cofeed; and (c) recovering from said reaction zone a dialkyl benzene isomer mix comprising a greater than thermodynamic equilibrium amount of the para-isomer thereof.
Claim 8
Dependent Claim
80 words
A process for producing dialkyl benzene products comprising: (a) introducing to a reaction zone containing a bed of a crystalline silica polymorph silicalite catalyst a monoalkyl benzene and an alkylating agent; (b) allowing said monoalkyl benzene and alkylating agent to come into contact with said silicalite catalyst material under conversion conditions which do not include steam cofeed; and (c) recovering from said reaction zone a dialkyl benzene isomer mix comprising a greater than thermodynamic equilibrium amount of the para-isomer thereof.
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) | 1987-12-25 | 1988-06-25 | 1988-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-12-25 | 1992-06-25 | 1992-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-12-25 | 1996-06-25 | 1996-12-25 | $7700.00 | Window Closed / Lapsed |