以油茶壳醇浸取后残渣为原料,以磷酸活化法制备活性炭,考察了浸渍比、磷酸质量分数和活化温度等对活性炭吸附性能及其得率的影响;活性炭的吸附性能由碘吸附值、亚甲基蓝吸附值表征。结果表明,在酸/炭浸渍比为3∶1、磷酸质量分数70%、活化温度500℃时,活性炭的吸附性能最佳,其碘、亚甲基蓝吸附值和得率分别为1043.29mg/g、148.5mg/g和38.77%。采用物理吸附仪在77K下测定其N2吸附脱附等温线,利用BET法和BJH法计算比表面积和孔径分布,其比表面积为1626.45m2/g,平均孔径为4.7nm,总孔容为1.94cm3/g。同时采用FTIR和XRD分析了活性炭的表面官能团和微观结构。
Activated carbons were prepared from camellia oleifera shell residue after alcohol extraction by phosphoric acid. The influences of impregnation ratio,mass fraction of phosphoric acid and activation temperature on the yield of activated carbon and the adsorption capacity were characterized by adsorption iodine value and adsorption methylene blue value,respectively. The results showed that activated carbon with the optimal adsorption capacity could be prepared at an impregnation ratio of acid/carbon of 3,a phosphoric acid mass fraction of 70% and an activation temperature of 500℃. The adsorption iodine value,adsorption methylene blue value and yield of activated carbon at optimized condition were 1043.29mg/g,148.5mg/g and 38.77%,respectively. Nitrogen adsorption isotherms at 77 K of the same activated carbon were measured by physical adsorption instrument. The porous structure was investigated by nitrogen adsorption isotherms on the bases of Brunauer-Emmett-Teller(BET) and Barrett- Joyner-Halenda(BJH) methods. The specific surface area,average pore size and pore volume were 1626.45m2/g,4.7nm and 1.94cm3/g,respectively. Surface functional group and micro-structures of activated carbon with the optimal adsorption capacity were analyzed by Fourier Transform Infrared Spectrometer(FTIR) and X-ray diffraction(XRD).