US4148750A
Expired / Lapsed
US
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Redispersion of noble metals on supported catalysts
Assignee: ExxonMobil Technology and Engineering Co
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Filing: 1977-01-10
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Granted: 1979-04-10
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Expires: 1997-01-10
Abstract
Abstract Noble metals on supported zeolite-containing hydrocarbon conversion catalysts, which have been at least partially damaged by thermal and/or hydrothermal stresses resulting in a maldistribution of the supported metal, are redispersed to a highly active, high surface area state by contacting said catalyst with ethylenediaminetetraacetic acid (EDTA), or a salt thereof, to the point of incipient wetness and then removing said acid by heat treatment.
Inventors
- 👤 Lloyd A. Pine
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:05
CPC Classifications
B; B01; B01J; B01J29/00; B01J29/90; B01J38/00; B01J38/48; B01J38/64; B01J38/66
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
91 words
A process for redispersing a noble metal on a supported zeolite-containing hydrocarbon conversion catalyst, at least a portion of said noble metal having become agglomerated, which comprises contacting said agglomerated catalyst with a solution containing at least a stoichiometric amount, based on the amount of noble metal present, of ethylenediaminetetraacetic acid or a salt thereof to incipient wetness for a time sufficient to redisperse a major portion of the metal throughout the catalyst, the temperature and pressure during said contacting being such that said solution is maintained in the liquid phase.
Claim 2
Dependent Claim
91 words
A process for redispersing a noble metal on a supported zeolite-containing hydrocarbon conversion catalyst, at least a portion of said noble metal having become agglomerated, which comprises contacting said agglomerated catalyst with a solution containing at least a stoichiometric amount, based on the amount of noble metal present, of ethylenediaminetetraacetic acid or a salt thereof to incipient wetness for a time sufficient to redisperse a major portion of the metal throughout the catalyst, the temperature and pressure during said contacting being such that said solution is maintained in the liquid phase.
Claim 3
Dependent Claim
26 words
The process of claim 1 wherein said salt of ethylenediaminetetraacetic acid is a Group I salt, an ammonium salt, an alkyl ammonium salt, or mixtures thereof.
Claim 4
Dependent Claim
10 words
The process of claim 1 wherein said solution is aqueous.
Claim 5
Dependent Claim
19 words
The process of claim 1 wherein the catalyst contains from about 0.01 to about 10 wt. % noble metal.
Claim 6
Dependent Claim
11 words
The process of claim 4 wherein the noble metal is palladium.
Claim 7
Dependent Claim
14 words
The process of claim 1 wherein redispersion is effected at ambient temperature and pressure.
Claim 8
Dependent Claim
22 words
The process of claim 1 wherein said salt of ethylenediaminetetraacetic acid is an ammonium salt, an alkyl ammonium salt or mixtures thereof.
Claim 9
Dependent Claim
41 words
The process of claim 1 wherein the catalyst is contacted with an oxygen-containing gas at a temperature ranging from about 700° to 1100° F. to burn-off carbon deposited thereon by contact with a hydrocarbon feedstock prior to contact with said solution.
Claim 10
Dependent Claim
113 words
A process for redispersing a noble metal on a supported zeolite-containing hydrocarbon conversion catalyst, at least a portion of said noble metal having become agglomerated during contact with an oxygen-containing gas at a temperature ranging from about 700° to 1100° F., which comprises contacting said agglomerated catalyst with a solution containing at least a stoichiometric amount, based on the amount of noble metal present, of ethylenediaminetetraacetic acid or a salt thereof to incipient wetness for a time sufficient to redisperse a major portion of the metal throughout the catalyst, the temperature and pressure during said contacting being such that said solution is maintained in the liquid phase, and thereafter drying the redispersed catalyst.
Claim 11
Dependent Claim
113 words
A process for redispersing a noble metal on a supported zeolite-containing hydrocarbon conversion catalyst, at least a portion of said noble metal having become agglomerated during contact with an oxygen-containing gas at a temperature ranging from about 700° to 1100° F., which comprises contacting said agglomerated catalyst with a solution containing at least a stoichiometric amount, based on the amount of noble metal present, of ethylenediaminetetraacetic acid or a salt thereof to incipient wetness for a time sufficient to redisperse a major portion of the metal throughout the catalyst, the temperature and pressure during said contacting being such that said solution is maintained in the liquid phase, and thereafter drying the redispersed catalyst.
Claim 12
Dependent Claim
26 words
The process of claim 9 wherein said salt of ethylenediaminetetraacetic acid is a Group I salt, an ammonium salt, an alkyl ammonium salt, or mixtures thereof.
Claim 13
Dependent Claim
10 words
The process of claim 9 wherein said solution is aqueous.
Claim 14
Dependent Claim
19 words
The process of claim 9 wherein the catalyst contains from about 0.01 to about 10 wt. % noble metal.
Claim 15
Dependent Claim
11 words
The process of claim 12 wherein the noble metal is palladium.
Claim 16
Dependent Claim
14 words
The process of claim 9 wherein redispersion is effected at ambient temperature and pressure.
Claim 17
Dependent Claim
22 words
The process of claim 9 wherein said salt of ethylenediaminetetraacetic acid is an ammonium salt, an alkyl ammonium salt or mixtures thereof.
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) | 1982-04-09 | 1982-10-09 | 1983-04-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-04-09 | 1986-10-09 | 1987-04-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-04-09 | 1990-10-09 | 1991-04-10 | $7700.00 | Window Closed / Lapsed |