US4039473A
Expired / Lapsed
US
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Active carbon by potassium ion exchange and leaching of carbonaceous material
Assignee: Commonwealth Scientific and Industrial Research Organisation
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Filing: 1976-03-18
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Granted: 1977-08-02
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Expires: 1996-03-18
Abstract
Abstract A high yield active carbon is obtained from brown coal, lignite and similar carbonaceous materials. The brown coal is converted into a potassium-coal by reaction with an aqueous solution containing potassium ions; the potassium-coal is carbonized (pyrolysed) and the char so produced is leached to remove the bound potassium ions. The potassium-coal can be tabletted or extruded prior to the carbonization. Surface areas of up to 1500 m2/g have been observed in the product. Additional activity can be achieved by subjecting the product to a conventional activation process.
Inventors
- 👤 Harry Neil Scott Schafer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:45
CPC Classifications
C; C01; C01B; C01B32/00; C01B32/30; C01B32/312; C01B32/342; C01B32/336
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
69 words
A process for producing an active carbon from carbonaceous material selected from the group consisting of brown coal and lignite comprising the sequential steps of: a. forming a potassium carbonaceous material by contacting the carbonaceous material with an aqueous solution of at least one ionizable potassium compound, b. pyrolysing the potassium-carbonaceous material to form a char, and c. leaching the char so obtained to remove the potassium cations therefrom.
Claim 2
Dependent Claim
69 words
A process for producing an active carbon from carbonaceous material selected from the group consisting of brown coal and lignite comprising the sequential steps of: a. forming a potassium carbonaceous material by contacting the carbonaceous material with an aqueous solution of at least one ionizable potassium compound, b. pyrolysing the potassium-carbonaceous material to form a char, and c. leaching the char so obtained to remove the potassium cations therefrom.
Claim 3
Dependent Claim
46 words
A process as defined in claim 1, wherein a. the aqueous solution contains one or more compounds selected from the group consisting of potassium hydroxide, potassium chloride and potassium acetate, and b. the pH of the aqueous solution is maintained at a value of about 8.3.
Claim 4
Dependent Claim
49 words
A process as defined in claim 1, wherein the carbonaceous material is first subjected to a pre-treatment comprising contacting the carbonaceous material with hydrochloric acid to effect substitution of the cations bound to the carboxylic acid groups of the carbonaceous material with the hydrogen ion of the hydrochloric acid.
Claim 5
Dependent Claim
25 words
A process as defined in claim 1, in which the potassium-carbonaceous material is separated from the aqueous solution and tabletted prior to the pyrolysis step.
Claim 6
Dependent Claim
35 words
A process as defined in claim 1, wherein the aqueous solution is of potassium hydroxide and the potassium-carbonaceous material is formed as a paste of dough-like consistency and is extruded prior to the pyrolysis step.
Claim 7
Dependent Claim
22 words
A process as defined in claim 1, wherein the product char is subjected to a conventional activation treatment to enhance its activity.
Claim 8
Dependent Claim
22 words
A process as defined in claim 4, wherein the product char is subjected to a conventional activation treatment to enhance its activity.
Claim 9
Dependent Claim
22 words
A process as defined in claim 5, wherein the product char is subjected to a conventional activation treatment to enhance its activity.
Claim 10
Dependent Claim
26 words
A process as defined in claim 7, in which the conventional activation treatment comprises reacting the char with steam at a temperature of about 800° C.
Claim 11
Dependent Claim
26 words
A process as defined in claim 8, in which the conventional activation treatment comprises reacting the char with steam at a temperature of about 800° C.
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) | 1980-08-01 | 1981-01-31 | 1981-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-01 | 1985-01-31 | 1985-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-01 | 1989-01-31 | 1989-08-02 | $7700.00 | Window Closed / Lapsed |