Method for the production of activated carbon spheres containing nitrogen
AssigneesKureha Kagaku Kogyo Kabushiki Kaisha, Toyo Boseki Kabushiki Kaisha
InventorsHatsuo Saito, Zenya Shiiki, Masaaki Nakao
Life of this patent
Estimating the term…
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.
Claims17
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.degree.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.
Dependencies are inferred from the claim text.