US4377718A
Expired / Lapsed
US
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Process for producing p-xylene
Assignee: Teijin Petrochemical Industries Ltd
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Filing: 1981-07-21
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Granted: 1983-03-22
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Expires: 2001-07-21
Abstract
Abstract In a process for producing p-xylene which comprises catalytically methylating toluene with a methylating agent in the gaseous phase, the improvement wherein (a) said methylation is carried out continuously in a multi-stage reaction system consisting of a plurality of separate series-connected fixed catalyst layers without separating the resulting xylenes in an intermediate stage, (b) said toluene is fed together with hydrogen gas into only the first-stage fixed catalyst layer and passed successively through the subsequent fixed catalyst layers, the amount of toluene fed being such that the total weight hourly space velocity of toluene is from 1 to 300 hr -1 , (c) said methylating agent is fed into each of said fixed catalyst layers, if desired together with hydrogen gas, the amount of the methylating agent fed into each catalyst layer being 0.01/t moles to 1/t moles, in which t is the number of methyl groups in the methylating agent, per mole of toluene fed into the first-stage catalyst layer, and the total amount of the methylating agent fed into all of the catalyst layers being within the range of 0.1/t moles to 2/t moles, in which t is as defined, per mole of toluene fed into the first-stage catalyst layer, and (d) each fixed catalyst layer is filled with a catalyst composed of a crystalline aluminosilicate containing magnesium oxide or lanthanide oxide.
Inventors
- 👤 Kimihiko Sato
- 👤 Tokuji Sakai
- 👤 Yasuo Yamasaki
- 👤 Tamio Onodera
- 👤 Koji Sumitani
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 13:51
CPC Classifications
C; C07; C07C; C07C2/00; C07C2/86; C07C2/862; C07C2/864; C07C2/865; C07C2529/00; C07C2529/04; C07C2529/06; C07C2529/40; C07C2529/42; C07C2529/44; Y; Y02; Y02P; Y02P20/00; Y02P20/50; Y02P20/52; Y02P20/584
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
224 words
In a process for producing p-xylene which comprises catalytically methylating toluene with a methylating agent in the gaseous phase, the improvement wherein (a) said methylation is carried out continuously in a multi-stage reaction system consisting of a plurality of separate series-connected fixed catalyst layers without separating the resulting xylenes in an intermediate stage, (b) said toluene is fed together with hydrogen gas into only the first-stage fixed catalyst layer and passed successively through the subsequent fixed catalyst layers, the amount of toluene fed being such that the total weight hourly space velocity of toluene is from 1 to 300 hr -1 , (c) said methylating agent is fed into each of said fixed catalyst layers, if desired together with hydrogen gas, the amount of the methylating agent fed into each catalyst layer being 0.01/t moles to 1/t moles, in which t is the number of methyl groups in the methylating agent, per mole of toluene fed into the first-stage catalyst layer, and the total amount of the methylating agent fed into all of the catalyst layers being within the range of 0.1/t moles to 2/t moles, in which t is as defined, per mole of toluene fed into the first-stage catalyst layer, and (d) each fixed catalyst layer is filled with a catalyst composed of a crystalline aluminosilicate containing magnesium oxide or lanthanide oxide.
Claim 2
Dependent Claim
224 words
In a process for producing p-xylene which comprises catalytically methylating toluene with a methylating agent in the gaseous phase, the improvement wherein (a) said methylation is carried out continuously in a multi-stage reaction system consisting of a plurality of separate series-connected fixed catalyst layers without separating the resulting xylenes in an intermediate stage, (b) said toluene is fed together with hydrogen gas into only the first-stage fixed catalyst layer and passed successively through the subsequent fixed catalyst layers, the amount of toluene fed being such that the total weight hourly space velocity of toluene is from 1 to 300 hr -1 , (c) said methylating agent is fed into each of said fixed catalyst layers, if desired together with hydrogen gas, the amount of the methylating agent fed into each catalyst layer being 0.01/t moles to 1/t moles, in which t is the number of methyl groups in the methylating agent, per mole of toluene fed into the first-stage catalyst layer, and the total amount of the methylating agent fed into all of the catalyst layers being within the range of 0.1/t moles to 2/t moles, in which t is as defined, per mole of toluene fed into the first-stage catalyst layer, and (d) each fixed catalyst layer is filled with a catalyst composed of a crystalline aluminosilicate containing magnesium oxide or lanthanide oxide.
Claim 3
Dependent Claim
17 words
The process of claim 1 wherein the multi-stage reaction system contains 2 to 20 fixed catalyst layers.
Claim 4
Dependent Claim
25 words
The process of claim 1 wherein the total weight hourly space velocity of toluene is in the range of 2 to 200 hr -1 .
Claim 5
Dependent Claim
33 words
The process of claim 1 wherein the amount of hydrogen gas fed into the first-stage fixed catalyst layer is 0.5 to 20 moles per mole of toluene fed into the first-stage catalyst layer.
Claim 6
Dependent Claim
44 words
The process of claim 1 wherein the amount of the methylating agent to be fed into each of the catalyst layers is 0.02/t to 0.5/t moles, wherein t is as defined in claim 1, per mole of toluene fed into the first-stage catalyst layer.
Claim 7
Dependent Claim
89 words
The process of claim 1 wherein the amount (Qi) of the methylating agent fed into the ith stage catalyst layer satisfies the following inequality ##EQU7## wherein Qi is the amount in moles of the methylating agent fed into the ith stage catalyst layer per mole of toluene fed into the first-stage catalyst layer, Qm is the amount in moles of the methylating agent fed into the mth stage catalyst layer per mole of the toluene fed into the first-stage catalyst layer, and t is as defined in claim 1.
Claim 8
Dependent Claim
36 words
The process of claim 1 wherein the total amount of the methylating agent fed into all of the catalyst layers is 0.1/t moles to 1.5/t moles per mole of toluene fed into the first-stage catalyst layer.
Claim 9
Dependent Claim
19 words
The process of claim 1 wherein the methylating agent is methanol or dimethyl ether or a mixture of these.
Claim 10
Dependent Claim
18 words
The process of claim 1 wherein the crystalline aluminosilicate has a silica/alumina mole ratio of at least 10.
Claim 11
Dependent Claim
25 words
The process of claim 1 wherein the catalyst contains 1 to 100% by weight of magnesium oxide based on the weight of the crystalline aluminosilicate.
Claim 12
Dependent Claim
24 words
The process of claim 1 wherein the catalyst contains 1 to 200% by weight of lanthanide oxide based on the weight of the aluminosilicate.
Claim 13
Dependent Claim
16 words
The process of claim 1 wherein the catalyst has an alpha value of 0.1 to 1,000.
Claim 14
Dependent Claim
25 words
The process of claim 1 wherein the catalyst has a weight ratio of cyclohexane to n-hexane sorptive capacity at 25° C. of 0.05 to 0.7.
Claim 15
Dependent Claim
15 words
The process of claim 1 wherein the catalyst further contains platinum, rhodium and or iridium.
Claim 16
Dependent Claim
26 words
The process of claim 15 wherein the catalyst contains 0.1 to 5% by weight of platinum, rhodium and/or iridium based on the weight of the aluminosilicate.
Claim 17
Dependent Claim
12 words
The process of claim 1 wherein the crystalline aluminosilicate is zeolite ZSM-5.
Claim 18
Dependent Claim
67 words
The process of claim 1 wherein the amount (Wi) of the catalyst filled in the ith stage fixed catalyst layer satisfies the following inequality ##EQU8## wherein Wi is the weight of the catalyst filled in the ith stage catalyst layer, Wm is the amount of the catalyst filled in the mth stage fixed catalyst layer, and n is the total number of the fixed catalyst layers used.
Claim 19
Dependent Claim
22 words
The process of claim 1 wherein the temperature of the inside of each catalyst layer is maintained at 250° to 700° C.
Claim 20
Dependent Claim
22 words
The process of claim 1 wherein the pressure of the inside of each catalyst layer is maintained at 1 to 20 atmospheres.
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) | 1986-03-21 | 1986-09-20 | 1987-03-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-03-21 | 1990-09-20 | 1991-03-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-03-21 | 1994-09-20 | 1995-03-22 | $7700.00 | Window Closed / Lapsed |