Production of an activated carbon having large specific surface area by chemical activation with new activating reagent

The activated carbon has very superior adsorption performance. Recently, an activated carbon having a large specific surface area has been produced by chemical activation with potassium hydroxide. However, potassium hydroxide is a powerful drug and has the disadvantage of being highly corrosive and must be handled with care. Therefore, in this study, potassium acetate was used as an activating agent. And the influences of the preparing conditions, such as carbonization temperature, impregnation ratio and holding time, on the pore structure (specific surface area and the pore volume) were investigated. Cellulose was used as a raw material in this study. Cellulose was impregnated with potassium acetate. In nitrogen flow, the impregnated samples were heated up to the carbonization temperature(500-1000 degreesC) at the heating rate of 10 degreesC/min and they were holding during the retention time(0-3h). The prepared char was washed by using hot water and was dried. The specific surface area of the prepared activated carbon was calculated by B.E.T. method using nitrogen adsorption isotherm at 77K. The specific surface area reached the maximum value at the carbonization temperature of 800 degreesC and at the retention time of 1h. And the specific surface area increased with a rise of the impregnation ratio. However, the change of the specific surface area was very small at the ratio of more than 1.0. The activated carbon having the specific surface area of 2,880 m2/g was produced from the cellulose impregnated with potassium acetate at the impregnation ratio of 1.0, at the carbonization temperature of 800 degreesC and at the retention time of 1h. Furthermore, when the methane adsorption isotherm at high pressure is measured on the activated carbon to evaluate the adsorption performance as a gas storage material, it has a methane gas storage capacity equal to that of the commercially available high specific surface area activated carbon.