热解活化法制备微孔发达椰壳活性炭及其吸附性能研究
Preparation and Adsorption Properties of Activated Carbon with Developed Micropore from Coconut Shell by Pyrolysis Activation
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摘要: 以椰壳为原料,采用热解活化法制备微孔发达活性炭。研究了活化温度、活化时间对活性炭孔结构和吸附性能的影响。实验结果表明:活化温度为 900 ℃,活化时间为 4 h,可制得比表面积为 994.42 m2/g 的微孔发达活性炭,其碘吸附值为 1 295 mg/g,亚甲基蓝吸附值为 135 mg/g。N2吸附结果表明活性炭的平均孔径在 2 nm 左右,总孔容积为 0.503 9 cm3/g,其中微孔容积为 0.430 3 cm3/g,微孔率达 85.39 %。对该活性炭进行CO2动态吸附实验,CO2饱和吸附容量为 56.61 mg/g,在热解活化法制备椰壳过程中,随着活化温度的升高和活化时间的延长,活性炭的得率有不同程度的降低。Abstract: Activated carbons were prepared from coconut shell by pyrolysis activation. The effects of activation temperature and time on pore structure and adsorption properties of activated carbons were investigated. The results showed that the prepared carbon has mainly micropore under the condition of activation temperature at 900 ℃ for 4 hours. The surface area of the prepared carbon is 994.42 m2/g with the iodine adsorption of 1 295 mg/g and methylene blue adsorption of 135 mg/g. The results of N2 adsorption showed that the average pore size of the activated carbon is around 2 nm. The micropore volume is 0.430 3 cm3/g and total pore volume of 0.503 9 cm3/g. This indicated that ratio of micropore is 85.39%. The results of CO2 dynamic adsorption showed that the adsorption qulity is up to 56.61 mg/g. With the increase of activation temperature and activation time, the yield of activated carbons is reduced at different degree, in the preparation of activated carbons from cocomt shell by carbonzation.
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