US4129523A
Expired / Lapsed
US
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Catalysts containing active metallic copper
Assignee: Imperial Chemical Industries Ltd
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Filing: 1976-10-28
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Granted: 1978-12-12
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Expires: 1996-10-28
Abstract
Abstract A catalyst containing metallic copper, especially a low temperature shift catalyst containing also zinc oxide, is made from a corresponding catalyst precursor by reduction in two stages. In the first stage a steam and/or CO2-diluted reducing gas is used and in the second a more strongly reducing gas mixture such as ammonia synthesis gas or even 100% hydrogen. The resulting catalyst is substantially more active than one reduced according to previous one-stage steam-reduction practice and similar to catalyst made by the less convenient dry-reduction using nitrogen or natural gas as diluent.
Inventors
- 👤 Paul Snowden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 09:37
CPC Classifications
B; B01; B01J; B01J37/00; B01J37/16; B01J37/18; B01J23/00; B01J23/70; B01J23/76; B01J23/80; C; C01; C01B; C01B3/00; C01B3/02; C01B3/06; C01B3/12; C01B3/16; Y; Y02; Y02P; Y02P20/00; Y02P20/50; Y02P20/52
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
181 words
A method of making a catalyst containing active metallic copper from a corresponding catalyst precursor containing copper oxide and zinc oxide in which the molar ratio of zinc oxide to copper oxide is 0.5-3:1, which comprises treating at a temperature of 275° C. or less the precursor with a reducing gas mixture containing steam, carbon dioxide or steam and carbon dioxide totaling at least 50% v/v of the mixture and a reducing gas selected from the group consisting of hydrogen, carbon monoxide and compounds that react readily to give hydrogen and/or carbon oxides the content of reducing gas, calculated as equivalent hydrogen, being less than 3% v/v, until a substantial part of the copper oxide has been reduced to metallic copper and thereafter treating it at a temperature of 275° C. or less with a more strongly reducing gas mixture consisting essentially of a reducing gas selected from the group consisting of hydrogen, carbon monoxide and compounds that react readily to give hydrogen and/or carbon oxides and less than 25% by volume of steam, carbon dioxide or carbon dioxide and steam.
Claim 2
Independent Claim
181 words
A method of making a catalyst containing active metallic copper from a corresponding catalyst precursor containing copper oxide and zinc oxide in which the molar ratio of zinc oxide to copper oxide is 0.5-3:1, which comprises treating at a temperature of 275° C. or less the precursor with a reducing gas mixture containing steam, carbon dioxide or steam and carbon dioxide totaling at least 50% v/v of the mixture and a reducing gas selected from the group consisting of hydrogen, carbon monoxide and compounds that react readily to give hydrogen and/or carbon oxides the content of reducing gas, calculated as equivalent hydrogen, being less than 3% v/v, until a substantial part of the copper oxide has been reduced to metallic copper and thereafter treating it at a temperature of 275° C. or less with a more strongly reducing gas mixture consisting essentially of a reducing gas selected from the group consisting of hydrogen, carbon monoxide and compounds that react readily to give hydrogen and/or carbon oxides and less than 25% by volume of steam, carbon dioxide or carbon dioxide and steam.
Claim 3
Dependent Claim
78 words
A method according to claim 1 in which the catalyst precursor is present in an uncooled bed and the content of reducing gas, calculated as equivalent hydrogen, in the mixture with at least 50% v/v of steam and/or carbon dioxide is under 3% v/v at the start of reduction, is maintained or increased to 3-10% v/v as the reduction proceeds, and is controlled during the reduction so that the temperature does not exceed 275° C. in the bed.
Claim 4
Dependent Claim
24 words
A method according to claim 1 in which the more strongly reducing gas mixture contains less than 5% v/v of steam and carbon dioxide.
Claim 5
Dependent Claim
51 words
A method according to claim 1 in which the product of the first stage of reduction is cooled, dried and, if necessary, stabilised by dilute oxygen, to give a pre-reduced catalyst, and the second stage of reduction is carried out in the reactor in which the catalyst is to be used.
Claim 6
Dependent Claim
32 words
A method according to claim 1 in which the catalyst precursor additionally contains 2.5 to 20% of alumina or 2.5 to 30% w/w of chromium oxide as Cr 2 O 3 .
Claim 7
Dependent Claim
30 words
A method according to claim 1 wherein said compounds that react readily to give hydrogen and/or carbon oxides are selected from the group consisting of methanol, dimethylether, methylformate and ammonia.
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) | 1981-12-11 | 1982-06-12 | 1982-12-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-12-11 | 1986-06-12 | 1986-12-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-12-11 | 1990-06-12 | 1990-12-12 | $7700.00 | Window Closed / Lapsed |