Process for production of activated carbon spheres
AssigneesKureha Kagaku Kogyo Kabushiki Kaisha, Toyo Boseki Kabushiki Kaisha
InventorsKunihiko Katori, Hiroshi Nagai, Zenya Shiiki
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Abstract
Microporous pitch spheres prepared from pitch are oxidized at a temperature of from 100.degree. C to 500.degree. C in an atmosphere of an oxidative gas to produce pitch spheres containing not less than 10% by weight of combined oxygen. Then the combined oxygen-containing pitch spheres are heated at a temperature of from 150.degree. C to 700.degree. C in an atmosphere of ammonia gas to produce pitch spheres containing not less than 1.5% by weight combined nitrogen. The resultant pitch spheres are subsequently activated by a conventional method to produce activated carbon spheres containing more than 1% by weight of combined nitrogen.
Claims6
A process for the production of activated carbon spheres, comprising:
- melting 100 parts by weight of a pitch in the presence of 10 to 50 parts by weight of naphthalene or tetralin to form a molten mixture;
- shaping said molten mixture into the form of spheres;
- contacting said spheres with a second solvent, said second solvent being compatible with the aromatic solvent, but lacking affinity for the pitch, to extract said aromatic solvent and to form microporous spheres;
- oxidizing said microporous spheres by heating said spheres at a temperature of from 100.degree. C to 400.degree. C in the presence of a gas containing 5-30% by volume oxygen to produce pitch spheres containing at least 10% by weight of combined oxygen;
- then
- heating said pitch spheres at a temperature in the range of from 150.degree. C to 700.degree. C in the presence of ammonia to produce pitch spheres having at least 1.5% by weight combined nitrogen;
- and
- activating said pitch spheres.
The process of claim 8 wherein the pitch is melted in the presence of naphthalene.
Dependencies are inferred from the claim text.