Patent US4412940A successfully refreshed from Google Patents.
US4412940A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for preparing maleic anhydride catalyst
Assignee: Huntsman Specialty Chemicals Corp
•
Filing: 1980-12-18
•
Granted: 1983-11-01
•
Expires: 2000-12-18
Abstract
Abstract An improvement in a method of preparing catalysts for the manufacture of maleic anhydride by oxidizing a saturated hydrocarbon. The catalyst is prepared by a process in which a catalyst precursor, containing tetravalent vanadium, is formed into agglomerates and calcined, the improvement being calcining the catalyst precursor at 325°-375° C. in the presence of oxygen and a saturated aliphatic hydrocarbon.
Inventors
- 👤 Ramon A. Mount
- 👤 Harold Raffelson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 13:13
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/16; C07C51/31; C07C51/313; B; B01; B01J; B01J23/00; B01J23/002; B01J27/00; B01J27/14; B01J27/186; B01J27/195; B01J27/198; C07C51/21; C07C51/215; B01J2523/00
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
101 words
In a method for the preparation of a phosphorus-vanadium-oxygen-containing complex catalyst comprising: (a) contacting vanadium and phosphorus compounds under conditions which will provide a catalyst precursor wherein greater than 50 atom % of the vanadium is in the tetravalent state; (b) recovering the catalyst precursor; (c) forming the catalyst precursor into agglomerates; and (d) calcining the catalyst precursor agglomerations at a temperature between about 300° C. and 600° C. the improvement consisting essentially of calcining in one temperature range at 325°-375° C. the catalyst precursor in the presence of a 0.1-1.5 mole percent concentration of a saturated aliphatic hydrocarbon in air.
Claim 2
Dependent Claim
101 words
In a method for the preparation of a phosphorus-vanadium-oxygen-containing complex catalyst comprising: (a) contacting vanadium and phosphorus compounds under conditions which will provide a catalyst precursor wherein greater than 50 atom % of the vanadium is in the tetravalent state; (b) recovering the catalyst precursor; (c) forming the catalyst precursor into agglomerates; and (d) calcining the catalyst precursor agglomerations at a temperature between about 300° C. and 600° C. the improvement consisting essentially of calcining in one temperature range at 325°-375° C. the catalyst precursor in the presence of a 0.1-1.5 mole percent concentration of a saturated aliphatic hydrocarbon in air.
Claim 3
Dependent Claim
13 words
The method improvement of claim 1 wherein the saturated aliphatic hydrocarbon is butane.
Claim 4
Dependent Claim
13 words
The method improvement of claim 1 wherein temperature of calcination is 345°-360° C.
Claim 5
Dependent Claim
14 words
The method improvement of claim 1 wherein temperature of calcination is about 350° C.
Claim 6
Dependent Claim
17 words
The method improvement of claim 2 wherein the concentration of butane in air is 0.8-1.2 mole percent.
References Cited (Backward Citations)
US3293268A
Cited
US3915892A
Cited
US3985775A
Cited
US4080312A
Cited
US4043943A
Cited
US4062873A
Cited
US4092269A
Cited
US4147661A
Cited
US4209423A
Cited
US4244879A
Cited
US4294722A
Cited
US4328120A
Cited
US4328126A
Cited
US4283307A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-10-31 | 1987-05-02 | 1987-11-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-31 | 1991-05-02 | 1991-11-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-31 | 1995-05-02 | 1995-11-01 | $7700.00 | Window Closed / Lapsed |