US4294722A
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Preparation of vanadium phosphorus catalysts
Assignee: Standard Oil Co
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Filing: 1980-05-19
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Granted: 1981-10-13
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Expires: 2000-05-19
Abstract
Abstract The present invention provides a method for the preparation of oxidation catalysts containing mixed oxides of vanadium and phosphorus, which catalysts are particularly effective in the oxidation of n-butane, n-butenes, 1,3-butadiene or a mixture thereof with molecular oxygen or an oxygen-containing gas in the vapor phase to produce improved yields of maleic anhydride with good selectivity. A vanadium compound is at least partially solubilized in an organic liquid medium capable of reducing at least a portion of the vanadium to a +4 valence state, and unsolubilized vanadium having a particle size larger than about 0.1 mm diameter is removed from the medium before addition of a phosphorus-containing compound.
Inventors
- 👤 Noel J. Bremer
- 👤 Dennis E. Dria
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 13:14
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/16; C07C51/21; C07C51/25; C07C51/252; B; B01; B01J; B01J23/00; B01J23/002; B01J27/00; B01J27/14; B01J27/186; B01J27/195; B01J27/198; C07C51/215; B01J2523/00; Y; Y10; Y10S; Y10S502/00; Y10S502/506; Y10S502/513
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
136 words
A process for the preparation of oxidation catalysts containing the mixed oxides of vanadium and phosphorus which comprises (a) introducing a pentavalent vanadium-compound into an organic liquid capable of at least partially solubilizing and capable of reducing vanadium to a valence state less than +5 to form a reaction medium in which at least a portion of said vanadium compound remains unsolubilized; (b) effecting reduction of at least a portion of said vanadium to a valence state of +4; (c) removing unsolubilized vanadium-containing compounds having a particle size greater than about 0.1 mm diameter; (d) adding a pentavalent phosphorus-containing compound to the reaction medium resulting from step (c) to form a catalytst precursor precipitate; (e) recovering said catalyst precursor precipitate; (f) drying said catalyst precursor precipitate; (g) calcining said precipitate to form the active oxidation catalyst.
Claim 2
Dependent Claim
136 words
A process for the preparation of oxidation catalysts containing the mixed oxides of vanadium and phosphorus which comprises (a) introducing a pentavalent vanadium-compound into an organic liquid capable of at least partially solubilizing and capable of reducing vanadium to a valence state less than +5 to form a reaction medium in which at least a portion of said vanadium compound remains unsolubilized; (b) effecting reduction of at least a portion of said vanadium to a valence state of +4; (c) removing unsolubilized vanadium-containing compounds having a particle size greater than about 0.1 mm diameter; (d) adding a pentavalent phosphorus-containing compound to the reaction medium resulting from step (c) to form a catalytst precursor precipitate; (e) recovering said catalyst precursor precipitate; (f) drying said catalyst precursor precipitate; (g) calcining said precipitate to form the active oxidation catalyst.
Claim 3
Dependent Claim
15 words
A process as recited in claim 1 wherein said organic liquid medium is essentially anhydrous.
Claim 4
Dependent Claim
23 words
A process as recited in claim 1 wherein reduction of said vanadium is effected by heating the vanadium-containing reaction medium of step (a).
Claim 5
Dependent Claim
26 words
A process as recited in claim 3 wherein reduction of said vanadium is effected by heating the vanadium-containing reaction medium of step (a) under reflux conditions.
Claim 6
Dependent Claim
16 words
A process as recited in claim 1 wherein said unsolubilized vanadium-containing compounds are removed by filtration.
Claim 7
Dependent Claim
33 words
A process as recited in claim 1 wherein said pentavalent phosphorus-containing compound is added to the reaction medium in the form of a solution of said pentavalent phosphorus-containing compound in said organic liquid.
Claim 8
Dependent Claim
14 words
A process as recited in claim 1 wherein said organic liquid is an alcohol.
Claim 9
Dependent Claim
13 words
A process as recited in claim 7 wherein said organic liquid is isobutanol.
Claim 10
Dependent Claim
14 words
A process as recited in claim 1 wherein said vanadium-containing compound is vanadium pentoxide.
Claim 11
Dependent Claim
14 words
A process as recited in claim 1 wherein said phosphorus-containing compound is orthophosphoric acid.
Claim 12
Dependent Claim
41 words
A process as recited in claim 1 wherein said oxidation catalyst is represented by the empirical formula: V.sub.l P.sub.a O.sub.x wherein a=1.0 to 1.2 and x is the number of oxygens required to satisfy the valence requirements of the other elements.
Claim 13
Dependent Claim
25 words
A process as recited in claim 1 wherein said oxidation catalyst is represented by the empirical formula V 1 P 1 .1 O x .
Claim 14
Dependent Claim
23 words
A process as recited in claim 1 wherein unsolubilized vanadium-containing compounds having a particle size greater than about 0.06 mm diameter are removed.
Claim 15
Dependent Claim
24 words
A process as recited in claim 1 wherein said unsolubilized vanadium-containing compounds having a particle size greater than about 0.04 mm diameter are removed.
Claim 16
Dependent Claim
134 words
An oxidation catalyst comprising the mixed oxides of vanadium and phosphorus prepared by the steps comprising: (a) introducing a pentavalent vanadium-compound into an organic liquid capable of at least partially solubilizing and capable of reducing vanadium to a valence state less than +5 to form a reaction medium in which at least a portion of said vanadium compound remains unsolubilized; (b) effecting reduction of at least a portion of said vanadium to a valence state of +4; (c) removing unsolubilized vanadium-containing compounds having a particle size greater than about 0.1 mm diameter; (d) adding a pentavalent phosphorus-containing compound to the reaction medium resulting from step (c) to form a catalyst precursor precipitate; (e) recovering said catalyst precursor precipitate; (f) drying said catalyst precursor precipitate; (g) calcining said precipitate to form the active oxidation catalyst.
Claim 17
Dependent Claim
134 words
An oxidation catalyst comprising the mixed oxides of vanadium and phosphorus prepared by the steps comprising: (a) introducing a pentavalent vanadium-compound into an organic liquid capable of at least partially solubilizing and capable of reducing vanadium to a valence state less than +5 to form a reaction medium in which at least a portion of said vanadium compound remains unsolubilized; (b) effecting reduction of at least a portion of said vanadium to a valence state of +4; (c) removing unsolubilized vanadium-containing compounds having a particle size greater than about 0.1 mm diameter; (d) adding a pentavalent phosphorus-containing compound to the reaction medium resulting from step (c) to form a catalyst precursor precipitate; (e) recovering said catalyst precursor precipitate; (f) drying said catalyst precursor precipitate; (g) calcining said precipitate to form the active oxidation catalyst.
Claim 18
Dependent Claim
38 words
An oxidation catalyst as recited in claim 15, further represented by the empirical formula: V.sub.l P.sub.a O.sub.x wherein a=1.0 to 1.2 and x is the number of oxygens required to satisfy the valence requirements of the other elements.
Claim 19
Dependent Claim
24 words
An oxidation catalyst as recited in claim 15, wherein unsolubilized vanadium-containing compounds having a particle size greater than about 0.06 mm diameter are removed.
Claim 20
Dependent Claim
24 words
An oxidation catalyst as recited in claim 15, wherein unsolubilized vanadium-containing compounds having a particle size greater than about 0.04 mm diameter are removed.
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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) | 1984-10-12 | 1985-04-13 | 1985-10-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-10-12 | 1989-04-13 | 1989-10-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-10-12 | 1993-04-13 | 1993-10-13 | $7700.00 | Window Closed / Lapsed |