Patent US4515899A successfully refreshed from Google Patents.
US4515899A
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Steam regeneration of phosphorus treated vanadium-phosphorus-oxygen catalysts
Assignee: Scientific Design LLC
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Filing: 1983-12-14
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Granted: 1985-05-07
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Expires: 2003-12-14
Abstract
Abstract The useful life of vanadium-phosphorus-oxygen (PVO) catalyst in fixed bed reactors can be substantially extended by treatment with a phosphorus compound followed by steam treatment. The PVO catalysts may be treated with steam after long periods (months) of only phosphorus compound treatment and the benefit of the present invention obtained or the phosphorus and steam treatments may be of only a few hours duration and sequential. In extending the useful life of the PVO catalyst according to the present invention, the temperature profile in the catalyst bed is restored to substantially the same profile as the fresh catalyst.
Inventors
- 👤 Gaylon T. Click
- 👤 Bruno J. Barone
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 09:13
CPC Classifications
B; B01; B01J; B01J27/00; B01J27/28; C; C07; C07C; C07C51/00; C07C51/16; C07C51/21; C07C51/215; B01J27/285; B01J38/00; B01J38/04; C07C51/25; C07C51/252; Y; Y02; Y02P; Y02P20/00; Y02P20/50; Y02P20/584
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
121 words
In a method for regenerating a vanadium-phosphorus - oxygen vapor phase oxidation catalyst used in the production of maleic anhydride from n-C 4 hydrocarbons containing P:V in an atomic ratio of 1/2 to 3:1 comprising contacting said catalyst with phosphorus compound of phosphorus halide, phosphorus oxyhalide, organic phosphines, organic phosphites, organic phosphates or mixtures thereof at a temperature in the range of about 0° to 600° C., whereby said catalyst exhibits a first yield wherein the improvement comprises thereafter contacting said catalyst with a flow of steam at a temperature in the range of about 300° C. to about 600° C. in an amount and for sufficient duration such that said catalyst exhibits a second yield greater than said first yield.
Claim 2
Dependent Claim
121 words
In a method for regenerating a vanadium-phosphorus - oxygen vapor phase oxidation catalyst used in the production of maleic anhydride from n-C 4 hydrocarbons containing P:V in an atomic ratio of 1/2 to 3:1 comprising contacting said catalyst with phosphorus compound of phosphorus halide, phosphorus oxyhalide, organic phosphines, organic phosphites, organic phosphates or mixtures thereof at a temperature in the range of about 0° to 600° C., whereby said catalyst exhibits a first yield wherein the improvement comprises thereafter contacting said catalyst with a flow of steam at a temperature in the range of about 300° C. to about 600° C. in an amount and for sufficient duration such that said catalyst exhibits a second yield greater than said first yield.
Claim 3
Dependent Claim
26 words
The method according to claim 1 wherein said contacting with said phosphorus compound is over an extended period of time prior to said contacting with steam.
Claim 4
Dependent Claim
16 words
The method according to claim 2 wherein said contacting with said phosphorus compound is substantially continuous.
Claim 5
Dependent Claim
15 words
The method according to claim 2 wherein said contacting with said phosphorus compound is intermittent.
Claim 6
Dependent Claim
18 words
The method according to claim 1 wherein said phosphorus compound contacting and said steam contacting are substantially contiguous.
Claim 7
Dependent Claim
18 words
The method according to claim 1 wherein said phosphorus compound contacting and steam contacting are repeated at intervals.
Claim 8
Dependent Claim
15 words
The method according to claim 1 wherein said phosphorus compound is vaporous during said contacting.
Claim 9
Dependent Claim
12 words
The method according to claim 1 wherein said phosphorus compound is inorganic.
Claim 10
Dependent Claim
12 words
The method according to claim 1 wherein said phosphorus compound is organic.
Claim 11
Dependent Claim
41 words
The method according to claim 1 wherein said phosphorus compound is an organo-phosphorus compound selected from the group consisting of ##STR2## wherein R is phenyl or an alkyl radical of one to 6 carbon atoms and X is H or R.
Claim 12
Dependent Claim
13 words
The method according in claim 10 wherein said organ-phosphorus compound is trimethyl phosphite.
Claim 13
Dependent Claim
33 words
The method according to claim 1 wherein said phosphorus compound is a phosphorus halide of the formula PX' n wherein X' is Cl, Br, I or F and n is 3 to 5.
Claim 14
Dependent Claim
14 words
The method according to claim 12 wherein said phosphorus halide is PCl 3 .
Claim 15
Dependent Claim
45 words
The method according to claim 1 wherein said phosphorus compound is an alkyl ester of phosphoric acid having the formula (R'O) 3 P═O wherein R' is hydrogen or an alkyl radical having one to six carbon atoms at least one R' being an alkyl radical.
Claim 16
Dependent Claim
12 words
The method according to claim 14 wherein said ester is trimethyl phosphate.
Claim 17
Dependent Claim
22 words
The method according to claim 1 wherein the amount of steam is at least equal to 20 weight percent of said catalyst.
References Cited (Backward Citations)
US30430A
Cited
US3296282A
Cited
US3474041A
Cited
GB1291354A
Cited
US3975407A
Cited
US3906008A
Cited
US4017521A
Cited
GB1439489A
Cited
GB1464198A
Cited
US4081460A
Cited
US4020174A
Cited
US4089807A
Cited
US4094816A
Cited
US4111832A
Cited
USRE30430E
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-05-06 | 1988-11-05 | 1989-05-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-05-06 | 1992-11-05 | 1993-05-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-05-06 | 1996-11-05 | 1997-05-07 | $7700.00 | Window Closed / Lapsed |