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US4003920A
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Method for producing maleic anhydride using a promoted tungsten, phosphorous oxide catalyst
Assignee: Kuraray Co Ltd
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Filing: 1973-11-30
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Granted: 1977-01-18
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Expires: 1993-11-30
Abstract
Abstract Maleic anhydride is obtained by oxidizing an unsaturated hydrocarbon having at least 4 carbon atoms in the presence of a catalyst comprising the oxides of tungsten and phosphorus, and at least one catalyst promoter selected from the groups consisting of a compound of a metallic element belonging to groups III A, III B, IV A and VIII of the Periodic Table; arsenic, zirconium, antimony, and niobium.
Inventors
- 👤 Ryuhei Ueeda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 12:10
CPC Classifications
C; C07; C07D; C07D307/00; C07D307/02; C07D307/34; B; B01; B01J; B01J23/00; B01J23/16; B01J23/24; B01J23/30; B01J23/70; B01J23/76; B01J23/84; B01J23/85; B01J23/888; B01J27/00; B01J27/14; B01J27/186; B01J27/188; B01J37/00; B01J37/28; C07C; C07C51/00; C07C51/16; C07C51/21; C07C51/215; C07C51/25; C07C51/252
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
86 words
A method for preparing maleic anhydride which comprises oxidizing in the vapor phase an unsaturated hydrocarbon selected from the group consisting of butene-1, butene-2, butadiene, cyclopentadiene, pentene-1, mixtures thereof and C 4 -fractions obtained by naphtha cracking in a reaction zone at a temperature of from 250° to 650° C, in the presence of a catalyst consisting essentially of the oxides of tungsten and phosphorous of a metallic element belonging to groups III-A, III-B, IV-A and VIII of the periodic table, arsenic, zirconium, antimony and niobium.
Claim 2
Independent Claim
86 words
A method for preparing maleic anhydride which comprises oxidizing in the vapor phase an unsaturated hydrocarbon selected from the group consisting of butene-1, butene-2, butadiene, cyclopentadiene, pentene-1, mixtures thereof and C 4 -fractions obtained by naphtha cracking in a reaction zone at a temperature of from 250° to 650° C, in the presence of a catalyst consisting essentially of the oxides of tungsten and phosphorous of a metallic element belonging to groups III-A, III-B, IV-A and VIII of the periodic table, arsenic, zirconium, antimony and niobium.
Claim 3
Dependent Claim
27 words
A method according to claim 1 wherein the metallic element of the catalyst promoter belongs to the groups III A or III B of the Periodic Table.
Claim 4
Dependent Claim
16 words
A method according to claim 1, wherein a phosphorus compound is introduced into the reaction zone.
Claim 5
Dependent Claim
14 words
A method according to claim 1 wherein the catalyst is supported on a carrier.
Claim 6
Dependent Claim
16 words
A method according to claim 2, wherein a phosphorus compound is introduced into the reaction zone.
Claim 7
Dependent Claim
14 words
A method according to claim 2 wherein the catalyst is supported on a carrier.
Claim 8
Dependent Claim
18 words
A method according to claim 1 wherein the atomic ratio of tungsten to phosphorus is less than 30.
Claim 9
Dependent Claim
25 words
A method according to claim 1 wherein oxidation is effected by admixing said unsaturated hydrocarbon with an oxidizing agent comprising oxygen or an oxygen-containing gas.
Claim 10
Dependent Claim
23 words
A method according to claim 8 wherein the molar ratio of unsaturated hydrocarbon to oxygen is less than 1/10 or more than 1/2.
Claim 11
Dependent Claim
23 words
A method according to claim 1 wherein the gaseous hourly space velocity through the reaction zone ranges from 500 to 15,000 per hour.
References Cited (Backward Citations)
US3156705A
Cited
US3296282A
Cited
US3478063A
Cited
FR1601955A
Cited
JPS4734313U
Cited
US3906008A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-01-18 | 1980-07-19 | 1981-01-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-01-18 | 1984-07-19 | 1985-01-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-01-18 | 1988-07-19 | 1989-01-18 | $7700.00 | Window Closed / Lapsed |