US4277376A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the manufacture of a monolithic support for catalysts suitable for use in controlling carbon monoxide emissions
Assignee: Centro Ricerche Fiat SCpA
•
Filing: 1979-07-16
•
Granted: 1981-07-07
•
Expires: 1999-07-16
Abstract
Abstract A monolithic support for a catalyst suitable for use in controlling carbon monoxide emission is prepared by forming a homogeneous, fluid semi-solid mass by admixing colloidal γ alumina, α alumina monohydrate and ceramic fibres with fluidizing and binding agents, water and a mineral acid, said acid being used in an amount sufficient to convert said α Al 2 O 3 monohydrate into a gel, forming the mass into a body of the desired shape, drying the body to substantially remove the added water, at least 10% of said added water being removed at a temperature lower than 50° C., and heat-treating the dried body at 800°-1000° C.
Inventors
- 👤 Sergio Paolasini
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:29
CPC Classifications
B; B01; B01J; B01J37/00; B01J37/0009; B01D; B01D53/00; B01D53/34; B01D53/74; B01D53/86; B01D53/864; B01J21/00; B01J21/02; B01J21/04; C; C04; C04B; C04B35/00; C04B35/01; C04B35/10; B01J35/00; B01J35/50; B01J35/56; Y; Y10; Y10S; Y10S502/00; Y10S502/506; Y10S502/507
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
180 words
A process for the manufacture of a monolithic support for a catalyst suitable for use in controlling carbon monoxide emissions, characterized by forming a homogeneous, fluid semi-solid mass by admixing a solid mixture comprising colloidal γ alumina having a grain size not exceeding 1 micron, α alumina monohydrate and ceramic fibres with one or more fluidising and binding agents for said mixture, water and a mineral acid, said αAl 2 O 3 monohydrate being used in an amount of from 40 to 60% by weight with respect to the total weight of the α and γ aluminas and said acid being used in an amount sufficient to convert said αAl 2 O 3 monohydrate into a gel, forming said mass into a body of the desired shape and provided with continuous channels, drying said body to substantially remove the added water, at least 10% of said added water being gradually removed at a temperature lower than 50° C., and heat-treating the dried body at a temperature of from 800° to 1000° C. to impart strength and porosity to the body.
Claim 2
Dependent Claim
180 words
A process for the manufacture of a monolithic support for a catalyst suitable for use in controlling carbon monoxide emissions, characterized by forming a homogeneous, fluid semi-solid mass by admixing a solid mixture comprising colloidal γ alumina having a grain size not exceeding 1 micron, α alumina monohydrate and ceramic fibres with one or more fluidising and binding agents for said mixture, water and a mineral acid, said αAl 2 O 3 monohydrate being used in an amount of from 40 to 60% by weight with respect to the total weight of the α and γ aluminas and said acid being used in an amount sufficient to convert said αAl 2 O 3 monohydrate into a gel, forming said mass into a body of the desired shape and provided with continuous channels, drying said body to substantially remove the added water, at least 10% of said added water being gradually removed at a temperature lower than 50° C., and heat-treating the dried body at a temperature of from 800° to 1000° C. to impart strength and porosity to the body.
Claim 3
Dependent Claim
12 words
The process of claim 1, wherein said mineral acid is hydrochloric acid.
Claim 4
Dependent Claim
17 words
The process of claim 1, wherein said γ alumina has a grain size not exceeding 0.1 micron.
Claim 5
Dependent Claim
19 words
The process of claim 1, wherein said α alumina has a grain size of from 1 to 100 microns.
Claim 6
Dependent Claim
19 words
The process of claim 1, wherein said α alumina has a grain size of from 1 to 20 microns.
Claim 7
Dependent Claim
22 words
The process of claim 1, wherein said α and γ aluminas have a surface area of at least 50 m 2 /g.
Claim 8
Dependent Claim
11 words
The process of claim 1, wherein said fibres are alumino-silicate fibres.
Claim 9
Dependent Claim
31 words
The process of claim 1, wherein said fibres are used in an amount of from 1 to 10% by weight with respect to the weight of said α and γ aluminas.
Claim 10
Dependent Claim
27 words
The process of claim 1, wherein said fluidising and binding agents are selected from the group consisting of carboxymethyl cellulose, methyl cellulose, polyvinyl alcohol, glycols and alginates.
Claim 11
Dependent Claim
15 words
The process of claim 1, wherein said fluidising and binding agent is carboxy methyl cellulose.
Claim 12
Dependent Claim
29 words
The process of claim 1, wherein said fluidising and binding agents are used in an amount of from 0.5 to 10% by weight with respect to said solid mixture.
Claim 13
Dependent Claim
29 words
The process of claim 1, wherein said fluidising and binding agents are used in an amount of from 0.5 to 3% by weight with respect to said solid mixture.
Claim 14
Dependent Claim
25 words
The process of claim 1, wherein said water is added in an amount of 100 to 130% by weight with respect to said solid mixture.
Claim 15
Dependent Claim
15 words
The process of claim 1, wherein said mass is formed into said body by extrusion.
Claim 16
Dependent Claim
52 words
The process of claim 1, wherein said added water is removed by a two-step drying, the first step being carried out at a temperature lower than 50° C. to remove at least 10% of said water and the second step being carried out at a temperature of from 50° to 200° C.
Claim 17
Dependent Claim
15 words
The process of claim 15, wherein said first step is carried out at ambient temperature.
Claim 18
Dependent Claim
20 words
The process of claim 15, wherein from 15 to 30% of said added water is removed at said first step.
Claim 19
Dependent Claim
21 words
The process of claim 15, wherein said first step is carried out for a period of from 10 to 100 hours.
Claim 20
Dependent Claim
19 words
The process of claim 15, wherein said second step is carried out at a temperature of about 100° C.
Claim 21
Dependent Claim
18 words
The process of claim 1, wherein said heat-treatment is carried out at a temperature of about 900° C.
Claim 22
Dependent Claim
21 words
The process of claim 1, wherein said body is brought to the heat-treatment temperature at a rate lower than 300° C./hr.
Claim 23
Dependent Claim
20 words
The process of claim 1, wherein said heat-treatment is carried out for a period of from 0.5 to 5 hours.
References Cited (Backward Citations)
US3554929A
Cited
US3856708A
Cited
US3912658A
Cited
US3850849A
Cited
US3944658A
Cited
US4082697A
Cited
US4075125A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-07-06 | 1985-01-05 | 1985-07-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-07-06 | 1989-01-05 | 1989-07-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-07-06 | 1993-01-05 | 1993-07-07 | $7700.00 | Window Closed / Lapsed |