Patent US4224302A successfully refreshed from Google Patents.
US4224302A
Expired / Lapsed
US
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Process for producing an alumina catalyst carrier
Assignee: Soken Inc
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Filing: 1979-03-05
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Granted: 1980-09-23
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Expires: 1999-03-05
Abstract
Abstract A catalyst carrier high in strength and suitable for use in internal combustion engines is produced by transforming a boehmite into γ-alumina at a high temperature, transforming the γ-alumina into α-alumina at a high temperature and sintering the α-alumina, boehmite having been prepared by forming a large number of agglomerates of adequate size from powdered aluminum hydroxide (Al 2 O 3 .3H 2 O) and contacting the agglomerates with water vapor at a high temperature and a high pressure to transform the aluminum hydroxide into boehmite.
Inventors
- 👤 Kunio Okamoto
- 👤 Junichiro Naito
- 👤 Mitsuru Asano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 23:20
CPC Classifications
C; C01; C01F; C01F7/00; C01F7/02; C01F7/44; C01F7/447; C01F7/448; B; B01; B01J; B01J21/00; B01J21/02; B01J21/04; C01P; C01P2004/00; C01P2004/50; C01P2004/60; C01P2004/61; C01P2006/00; C01P2006/10; C01P2006/12; C01P2006/14; C01P2006/21
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
130 words
A method for preparing boehmite from powdered aluminum hydroxide (Al 2 O 3 .3H 2 O) comprising the steps of: providing a first aluminum hydroxide having a particle diameter of about 40μ; mixing said first aluminum hydroxide with an equal amount of a second aluminum hydroxide having a particle diameter of about 3μ; admixing the resulting mixture with an aqueous solution of methylcellulose; forming the resulting mixture of the first and second aluminum hydroxide and the aqueous solution of methylcellulose into agglomerates having a diameter of 3 to 4 mm; and contacting the agglomerates with water vapor at a temperature of at least about 170° C. and a pressure of at least about 6 kg/cm 2 to transform the aluminum hydroxide into boehmite (Al 2 O 3 .H 2 O).
Claim 2
Independent Claim
130 words
A method for preparing boehmite from powdered aluminum hydroxide (Al 2 O 3 .3H 2 O) comprising the steps of: providing a first aluminum hydroxide having a particle diameter of about 40μ; mixing said first aluminum hydroxide with an equal amount of a second aluminum hydroxide having a particle diameter of about 3μ; admixing the resulting mixture with an aqueous solution of methylcellulose; forming the resulting mixture of the first and second aluminum hydroxide and the aqueous solution of methylcellulose into agglomerates having a diameter of 3 to 4 mm; and contacting the agglomerates with water vapor at a temperature of at least about 170° C. and a pressure of at least about 6 kg/cm 2 to transform the aluminum hydroxide into boehmite (Al 2 O 3 .H 2 O).
Claim 3
Dependent Claim
147 words
A process for producing a catalyst carrier from powdered aluminum hydroxide comprising the steps of: providing a first powdered aluminum hydroxide having a particle diameter of about 40μ; mixing said first powdered aluminum hydroxide with an equal amount of a second powdered aluminum hydroxide having a particle diameter of about 3μ; admixing the resulting mixture with an aqueous solution of methylcellulose; forming the resulting mixture of the first and second powdered aluminum hydroxide and the aqueous solution of methylcellulose into agglomerates having a diameter of 3 to 4 mm; contacting said agglomerates with water vapor at a temperature of at least about 170° C. and a pressure of at least about 6 kg/cm 2 to transform the aluminum hydroxide into boehmite; and transforming said boehmite into γ-alumina and then transforming the γ-alumina into α-alumina at a temperature of at least about 1150° C. and sintering said α-alumina.
Claim 4
Dependent Claim
147 words
A process for producing a catalyst carrier from powdered aluminum hydroxide comprising the steps of: providing a first powdered aluminum hydroxide having a particle diameter of about 40μ; mixing said first powdered aluminum hydroxide with an equal amount of a second powdered aluminum hydroxide having a particle diameter of about 3μ; admixing the resulting mixture with an aqueous solution of methylcellulose; forming the resulting mixture of the first and second powdered aluminum hydroxide and the aqueous solution of methylcellulose into agglomerates having a diameter of 3 to 4 mm; contacting said agglomerates with water vapor at a temperature of at least about 170° C. and a pressure of at least about 6 kg/cm 2 to transform the aluminum hydroxide into boehmite; and transforming said boehmite into γ-alumina and then transforming the γ-alumina into α-alumina at a temperature of at least about 1150° C. and sintering said α-alumina.
Claim 5
Dependent Claim
34 words
A process for producing a catalyst carrier according to claim 2, wherein the step of transforming the boehmite into the γ-alumina is carried out at a high temperature of 600° C. for 2 hours.
Claim 6
Dependent Claim
34 words
A process for producing a catalyst carrier according to claim 2, wherein the step of transforming the γ-alumina into the α-alumina is carried out at a high temperature of 1,200° C. for 2 hours.
Claim 7
Dependent Claim
26 words
A process according to claim 2 wherein the boehmite is transformed into γ-alumina at 600° C. and the γ-alumina is transferred into α-lumina at 1200° C.
References Cited (Backward Citations)
US3392125A
Cited
US3628914A
Cited
US3582271A
Cited
US3853789A
Cited
US3945945A
Cited
US3975510A
Cited
US3850849A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-09-23 | 1984-03-24 | 1984-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-09-23 | 1988-03-24 | 1988-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-09-23 | 1992-03-24 | 1992-09-23 | $7700.00 | Window Closed / Lapsed |