US3953345A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for the production of activated carbon spheres containing nitrogen
Assignee: Kureha Corp
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Filing: 1974-05-28
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Granted: 1976-04-27
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Expires: 1994-05-28
Abstract
Abstract Spheres of activated carbon are obtained by adding to 100 parts by weight of pitch 10 to 50 parts by weight of an aromatic solvent compatible with said pitch and 2 to 50% by weight, based on the total weight of said pitch and said aromatic solvent, of a nitrogen-containing compound, melting and mixing them with one another, molding the resultant mixture in the form of spheres, removing the aromatic solvent by means of solvent extraction to convert said spheres into porous pitch spheres containing 2 to 60% by weight of nitrogen, infusibilizing the resultant micro-porous pitch spheres and thereafter activating the infusibilized pitch spheres.
Inventors
- 👤 Hatsuo Saito
- 👤 Zenya Shiiki
- 👤 Masaaki Nakao
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:08
CPC Classifications
C; C01; C01B; C01B17/00; C01B17/69; C01B17/74; C01B17/76; C01B17/775; B; B01; B01J; B01J21/00; B01J21/18; B01J35/00; B01J35/50; B01J35/51; B01J37/00; B01J37/0009; B01J37/0018; C01B32/00; C01B32/30; C01B32/354; C01B32/384
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
170 words
A method for the production of activated carbon spheres comprising: mixing 100 parts by weight of pitch having a softening point of not less than 70°C, an H/C ratio of not more than 1, and a nitrobenzene-insoluble content of not more than 40%, with 10-50 parts by weight of an aromatic hydrocarbon solvent compatible with the pitch and 2-50% by weight, based on the total weight of the pitch and aromatic solvent, of a nitrogen compound containing at least 10% by weight nitrogen and miscible with said pitch; melting the mixture; shaping the melted mixture into the form of spheres; contacting the spheres with an organic solvent which is compatible with the aromatic solvent but which lacks affinity for the pitch to extract the aromatic solvent from the spheres, thereby forming micro-pores in the spheres; contacting the microporous spheres with an aqueous or gaseous oxidizing agent to render them infusible; and activating the infusibilized pitch spheres with an activating gas, to form activated carbon spheres containing 2-60% by weight nitrogen.
Claim 2
Independent Claim
170 words
A method for the production of activated carbon spheres comprising: mixing 100 parts by weight of pitch having a softening point of not less than 70°C, an H/C ratio of not more than 1, and a nitrobenzene-insoluble content of not more than 40%, with 10-50 parts by weight of an aromatic hydrocarbon solvent compatible with the pitch and 2-50% by weight, based on the total weight of the pitch and aromatic solvent, of a nitrogen compound containing at least 10% by weight nitrogen and miscible with said pitch; melting the mixture; shaping the melted mixture into the form of spheres; contacting the spheres with an organic solvent which is compatible with the aromatic solvent but which lacks affinity for the pitch to extract the aromatic solvent from the spheres, thereby forming micro-pores in the spheres; contacting the microporous spheres with an aqueous or gaseous oxidizing agent to render them infusible; and activating the infusibilized pitch spheres with an activating gas, to form activated carbon spheres containing 2-60% by weight nitrogen.
Claim 3
Dependent Claim
59 words
The method of claim 1 wherein the activating step is effected by contacting the spheres with an activating gas at a temperature within the range of 800°C-1100°C, said activating gas being selected from steam, CO 2 , mixtures of steam and CO 2 , and mixtures of these gases with at least one gas selected from nitrogen and oxygen.
Claim 4
Dependent Claim
25 words
The method of claim 1 wherein said aromatic solvent is selected from benzene, toluene, xylene, naphthalene, tetralin, methyl naphthalene, naphthalene-containing oil fractions and BTX fractions.
Claim 5
Dependent Claim
40 words
The method of claim 1 wherein said nitrogen-containing compound is selected from nitrogen-containing inorganic compounds, nitrogen-containing high molecular weight compounds, nitrogen-containing heterocyclic compounds, nitrogen-containing aromatic hydrocarbon derivatives, aliphatic amines, guanidine, guanidine derivatives, urea, urea derivatives, semicarbazine and nitrogen-containing alicyclic compounds.
Claim 6
Dependent Claim
22 words
The method of claim 4 wherein said nitrogen-containing inorganic compound is selected from ammonium phosphate, ammonium nitrate, sodium nitrate and potassium nitrate.
Claim 7
Dependent Claim
24 words
The method of claim 4 wherein said nitrogen-containing high molecular weight compound is selected from polyacrylonitrile, polyacrylamide, melamine resins, urea resins, polyimides and proteins.
Claim 8
Dependent Claim
25 words
The method of claim 4 wherein said nitrogen-containing heterocyclic compound is selected from melamine, benzoguanamine, urotropin, pyrimidine, piperazine, imidazole, benzoimidazole, quinoline, isoquinoline, indole and pyridine.
Claim 9
Dependent Claim
20 words
The method of claim 4 wherein said nitrogen-containing aromatic hydrocarbon derivative is selected from polyaminobenzene, polyaminonaphthalene, polynitrilebenzene, polynitrosobenzene, and polynitrobenzene.
Claim 10
Dependent Claim
13 words
The method of claim 4 wherein said aliphatic amine is 1,4-diaminobutane or hexamethylenediamine.
Claim 11
Dependent Claim
11 words
The method of claim 4 wherein said guanidine derivative is dicyandiamide.
Claim 12
Dependent Claim
14 words
The method of claim 4 wherein said urea derivative is dimethyl urea or N-nitrourea.
Claim 13
Dependent Claim
13 words
The method of claim 4 wherein said nitrogen-containing alicyclic compound is N,N-dimethylcyclohexyl amine.
Claim 14
Dependent Claim
21 words
The method of claim 1 wherein said extracting is by contacting the spheres with an alcohol or a paraffinic hydrocarbon solvent.
Claim 15
Dependent Claim
15 words
The method of claim 13 wherein said alcohol is selected from methanol, ethanol and propanol.
Claim 16
Dependent Claim
18 words
The method of claim 13 wherein said paraffinic hydrocarbon solvent is selected from hexane, heptane and light naphtha.
Claim 17
Dependent Claim
36 words
The method of claim 2 wherein said gaseous oxidizing agent is selected from air, oxygen, nitrogen oxide, mixtures containing at least one of these gases with nitrogen, and mixtures of two or more of these gases.
Claim 18
Dependent Claim
21 words
The method of claim 1 wherein said aromatic solvent has a boiling point in the range of from 70°C to 250°C.
References Cited (Backward Citations)
FR1458195A
Cited
US3786134A
Cited
US3668110A
Cited
US3775344A
Cited
US3823221A
Cited
US3917806A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-04-27 | 1979-10-27 | 1980-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-04-27 | 1983-10-27 | 1984-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-04-27 | 1987-10-27 | 1988-04-27 | $7700.00 | Window Closed / Lapsed |