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US 4,699,896 AGranted
Manufacture of fibrous activated carbons
AssigneeThe Secretary of State for Defence in Her Britannic Majesty's Government of the United Kingdom of Great Britain and Northern Ireland
InventorsKenneth S. W. Sing, Frederick G. R. Gimblett, John J. Freeman
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Abstract
A method of preparing a fibrous activated carbon including the steps of carbonizing and activating cellulose fibre at temperatures between 200.degree. C. and 1000.degree. C. in an inert atmosphere, characterized in that, prior to activation, the fibre is impregnated with an impregnating material comprising, in the form of one or more compounds, boron and at least one alkali metal.
Claims15
A method of preparing a fibrous activated carbon which comprises the steps of
- (a) carbonizing cellulose fibre in an inert atmosphere at a temperature between 200.degree. and 600.degree. C., and
- (b) activating the carbonized cellulose fibre in an inert atmosphere at a temperature between 450.degree. and 1000.degree. C. until the fibrous activated carbon product has a BET surface area in excess of 500 m.sup.2 g.sup.-1,
- wherein prior to step (b) the cellulose fibre is impregnated with an impregnating material consisting of the elements boron and at least one alkali metal, said elements being in the form of one or more compounds, such that after impregnation the amount of alkali metal on the fibre is from 0.01 to 10% by weight of the fibre and the amount of boron on the fiber is from 0.01 to 10% by weight of the fibre, whereby the fibrous activated carbon product of step (b) has a mesopore content of at least 15% of its total pore volume.
Dependencies are inferred from the claim text.