Selection and preparation of activated carbon for fuel gas storage
First Claim
1. A method of preparing an activated carbon for enhanced sorption of hydrogen or a hydrogen-containing gas, comprising the steps ofselecting a source carbon material that has a low ash content on the order of 3% or less and whose ash content contains a relatively small silicon content on the order of 1000 μ
- g/g or less and a relatively small transition metal content on the order of 3000 μ
g/g or less, and whose ash content predominantly consists of alkali metals and/or alkali earths;
washing the selected source carbon in an aqueous nonbasic wash to reduce said ash content and to reduce the pH of the carbon;
treating the washed carbon in a flow of oxygen and an inert gas at an elevated temperature to create acidic or basic functional sites on said carbon.
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Accused Products
Abstract
Increasing the surface acidity of active carbons can lead to an increase in capacity for hydrogen adsorption. Increasing the surface basicity can facilitate methane adsorption. The treatment of carbons is most effective when the carbon source material is selected to have a low ash content i.e., below about 3%, and where the ash consists predominantly of alkali metals alkali earth, with only minimal amounts of transition metals and silicon. The carbon is washed in water or acid and then oxidized, e.g. in a stream of oxygen and an inert gas at an elevated temperature.
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Citations
10 Claims
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1. A method of preparing an activated carbon for enhanced sorption of hydrogen or a hydrogen-containing gas, comprising the steps of
selecting a source carbon material that has a low ash content on the order of 3% or less and whose ash content contains a relatively small silicon content on the order of 1000 μ - g/g or less and a relatively small transition metal content on the order of 3000 μ
g/g or less, and whose ash content predominantly consists of alkali metals and/or alkali earths;washing the selected source carbon in an aqueous nonbasic wash to reduce said ash content and to reduce the pH of the carbon; treating the washed carbon in a flow of oxygen and an inert gas at an elevated temperature to create acidic or basic functional sites on said carbon. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
- g/g or less and a relatively small transition metal content on the order of 3000 μ
Specification