US3981823A
Expired / Lapsed
US
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Regeneration of iridium-containing catalysts
Assignee: ExxonMobil Technology and Engineering Co
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Filing: 1974-09-23
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Granted: 1976-09-21
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Expires: 1994-09-23
Abstract
Abstract The instant invention relates to a process for activating iridium-containing catalysts, said catalysts being inactive because of the presence of the iridium as large crystallites of low activity, and which comprises the step of contacting said catalyst with a halogen-containing gas in the presence of from 0.01 to 10% by volume oxygen, at a temperature of at least 300°C. for a time sufficient to redisperse said large crystallites to crystallites having a substantially smaller particle size. Preferably, the catalyst is a reforming catalyst comprising iridium supported on alumina. In the most preferred embodiment of the instant invention an iridium: platinum on alumina catalyst, which has become deactivated by use in a reforming process wherein carbonaceous materials have deposited on the surface of the catalyst, is regenerated by (1) burning off said carbonaceous deposits by contacting said catalyst with oxygen at a temperature of at least 300°C. for a time sufficient to substantially remove said carbonaceous materials, (2) contacting said catalyst with hydrogen at a temperature and time sufficient to reduce said iridium and platinum substantially to metallic form, and (3) redispersing said metals by contacting said reduced catalyst with oxygen and a halogen-containing gas, e.g., chlorine, the oxygen being present in an amount of less than 10% oxygen by volume, at a temperature of at least 300°C.
Inventors
- 👤 David J. C. Yates
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:47
CPC Classifications
C; C10; C10G; C10G35/00; C10G35/04; C10G35/06; C10G35/085; C10G35/09; B; B01; B01J; B01J23/00; B01J23/90; B01J23/96; B01J37/00; B01J37/22; B01J37/24
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
196 words
A process for regenerating a supported hydrocarbon reforming catalyst containing at least about 0.1 wt. % iridium in the metallic form, wherein the support is a refractory inorganic oxide, the catalyst being at least partially deactivated by the presence of carbonaceous deposits thereon which comprises the steps of (1) contacting said catalyst with an oxygen-containing gas at a temperature of at least 300°C. for a time sufficient to burn at least a substantial portion of said carbonaceous deposits from said catalyst; (2) contacting catalyst treated in step (1) with a reducing gas selected from the group consisting of hydrogen, carbon monoxide, nitric oxide, and mixtures thereof at an elevated temperature for a time sufficient to convert at least a portion of said iridium to its metallic form; and (3) contacting the catalyst containing iridium at least a portion of which has been reduced to the metallic form with a gas containing a halogen and oxygen at a temperature of at least 300°C., the oxygen being present in an amount sufficient to enhance the dispersion of the iridium on the catalyst but less than 5% by volume, at an oxygen partial pressure not exceeding about 0.1 atmosphere.
Claim 2
Dependent Claim
196 words
A process for regenerating a supported hydrocarbon reforming catalyst containing at least about 0.1 wt. % iridium in the metallic form, wherein the support is a refractory inorganic oxide, the catalyst being at least partially deactivated by the presence of carbonaceous deposits thereon which comprises the steps of (1) contacting said catalyst with an oxygen-containing gas at a temperature of at least 300°C. for a time sufficient to burn at least a substantial portion of said carbonaceous deposits from said catalyst; (2) contacting catalyst treated in step (1) with a reducing gas selected from the group consisting of hydrogen, carbon monoxide, nitric oxide, and mixtures thereof at an elevated temperature for a time sufficient to convert at least a portion of said iridium to its metallic form; and (3) contacting the catalyst containing iridium at least a portion of which has been reduced to the metallic form with a gas containing a halogen and oxygen at a temperature of at least 300°C., the oxygen being present in an amount sufficient to enhance the dispersion of the iridium on the catalyst but less than 5% by volume, at an oxygen partial pressure not exceeding about 0.1 atmosphere.
Claim 3
Dependent Claim
11 words
The process of claim 1 wherein the reducing gas is hydrogen.
Claim 4
Dependent Claim
20 words
The process of claim 1 wherein the oxygen is present in an amount ranging from 0.1 to 5 volume %.
Claim 5
Dependent Claim
12 words
The process of claim 1 wherein the halogen containing gas contains chlorine.
Claim 6
Dependent Claim
10 words
The process of claim 4 wherein the support is alumina.
Claim 7
Dependent Claim
34 words
The process of claim 4 wherein the catalyst is comprised of iridium and a metal selected from the group consisting of Groups IB, VIB, VIIB and VIII of the Periodic Table of the Elements.
Claim 8
Dependent Claim
14 words
The process of claim 6 wherein the catalyst is comprised of iridium and platinum.
Claim 9
Dependent Claim
28 words
The process of claim 1 wherein the halogen is chlorine and the gas of step (3) is comprised of chlorine and 0.1 to 1.0 volume % of oxygen.
Claim 10
Dependent Claim
185 words
A process for regenerating a hydrocarbon reforming catalyst containing from 0.01 to 1.0 wt. % iridium in the metallic form and supported on a refractory inorganic oxide, said catalyst being at least partially deactivated by the presence of carbonaceous deposits thereon which comprises the steps of (1) contacting said catalyst with an oxygen-containing gas at a temperature of at least 300°C. for a time sufficient to burn at least a substantial portion of said carbonaceous deposits from said catalyst; (2) contacting the treated catalyst with hydrogen at a temperature of at least 100°C. for a time sufficient to convert a portion of said iridium to its metallic form; and (3) contacting the catalyst containing iridium at least a portion of which has been reduced to its metallic form with a gas containing a halogen and about 0.1 to 5 volume % oxygen, at an oxygen partial pressure not exceeding avbout 0.1 atmosphere at a temperature of at least 300°C. and for a time sufficient to enhance the dispersion of the iridium on the catalyst to a value greater than that of the partially deactivated catalyst.
Claim 11
Dependent Claim
185 words
A process for regenerating a hydrocarbon reforming catalyst containing from 0.01 to 1.0 wt. % iridium in the metallic form and supported on a refractory inorganic oxide, said catalyst being at least partially deactivated by the presence of carbonaceous deposits thereon which comprises the steps of (1) contacting said catalyst with an oxygen-containing gas at a temperature of at least 300°C. for a time sufficient to burn at least a substantial portion of said carbonaceous deposits from said catalyst; (2) contacting the treated catalyst with hydrogen at a temperature of at least 100°C. for a time sufficient to convert a portion of said iridium to its metallic form; and (3) contacting the catalyst containing iridium at least a portion of which has been reduced to its metallic form with a gas containing a halogen and about 0.1 to 5 volume % oxygen, at an oxygen partial pressure not exceeding avbout 0.1 atmosphere at a temperature of at least 300°C. and for a time sufficient to enhance the dispersion of the iridium on the catalyst to a value greater than that of the partially deactivated catalyst.
Claim 12
Dependent Claim
10 words
The process of claim 9 wherein the halogen is chlorine.
Claim 13
Dependent Claim
23 words
The process of claim 9 wherein the oxygen in step (3) is present in an amount of about 0.1 to 0.3 volume %.
Claim 14
Dependent Claim
16 words
The process of claim 9 wherein step (3) is conducted at a temperature of about 450°-550°C.
Claim 15
Dependent Claim
188 words
A process for regenerating an alumina supported naphtha reforming catalyst containing platinum and at least about 0.1 wt. % iridium in the metallic form, said catalyst being at least partially deactivated by the presence of carbonaceous deposits thereon which comprises the steps of (1) contacting said catalyst with an oxygen-containing gas at a temperature of about 300° to 600°C. for a time sufficient to burn at least a substantial portion of said carbonaceous deposits from said catalyst; (2) contacting the treated catalyst with hydrogen at a temperature between about 200°- 550°C. for a time sufficient to convert at least a portion of said iridium and platinum to their metallic form; and (3) contacting the catalyst containing platinum and iridium at least portions of which have been reduced to their metallic form with a gas comprising chlorine and from about 0.1 - 5.0 volume % oxygen, at an oxygen parital pressure not exceeding about 0.1 atmosphere at a temperature of at least about 300°C. for a time sufficient to increase the surface area of the iridium and platinum on said catalyst to at least about 200 m 2 /gm.
Claim 16
Dependent Claim
188 words
A process for regenerating an alumina supported naphtha reforming catalyst containing platinum and at least about 0.1 wt. % iridium in the metallic form, said catalyst being at least partially deactivated by the presence of carbonaceous deposits thereon which comprises the steps of (1) contacting said catalyst with an oxygen-containing gas at a temperature of about 300° to 600°C. for a time sufficient to burn at least a substantial portion of said carbonaceous deposits from said catalyst; (2) contacting the treated catalyst with hydrogen at a temperature between about 200°- 550°C. for a time sufficient to convert at least a portion of said iridium and platinum to their metallic form; and (3) contacting the catalyst containing platinum and iridium at least portions of which have been reduced to their metallic form with a gas comprising chlorine and from about 0.1 - 5.0 volume % oxygen, at an oxygen parital pressure not exceeding about 0.1 atmosphere at a temperature of at least about 300°C. for a time sufficient to increase the surface area of the iridium and platinum on said catalyst to at least about 200 m 2 /gm.
Claim 17
Dependent Claim
23 words
The process of claim 13 wherein the oxygen of step (3) is present in an amount of about 0.1 to 1.0% by volume.
Claim 18
Dependent Claim
16 words
The process of claim 14 wherein step (3) is conducted at a temperature of about 450°-550°c.
Claim 19
Dependent Claim
33 words
The process of claim 14 wherein the regeneration of the catalyst includes a purge step subsequent to the reduction step but prior to treating the catalyst with the gas comprising chlorine and oxygen.
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) | 1979-09-21 | 1980-03-22 | 1980-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-09-21 | 1984-03-22 | 1984-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-09-21 | 1988-03-22 | 1988-09-21 | $7700.00 | Window Closed / Lapsed |