CO_2活化烟杆制造活性炭及其孔结构表征

Activated Carbon Made from Tobacco Stalk with CO_2 Activation and its Pore Characterization

为综合利用烟杆废弃物资源,以烟杆为原料,CO2为活化剂制备成活性炭。采用正交试验方法研究了CO2流量、活化时间和活化温度对活性炭得率及吸附性能的影响,同时测定了该活性炭的氮吸附等温线,并通过BET法、H-K方程、D-A方程和密度函数理论表征了活性炭的孔结构,还采用电子探针和透射电镜分析了活性炭的微观结构。结果表明:①适宜的工艺条件为活化温度800℃,时间30min,CO2流量3L/min,在此条件下制得的活性炭的得率为9.47%,碘吸附值为1079.26mg/g,亚甲基蓝吸附值为67.5mg/g;②所得活性炭为微孔孔型,BET比表面积为761m2/g,总孔体积为0.3521cm3/g,微孔体积占总孔体积的95.54%,中孔占3.85%,大孔占0.61%;③电子探针和电镜分析测定的活性炭的结构与氮吸附测定的结果较为一致。

In order to make use of tobacco stalk, activated carbon was prepared from tobacco stalk with carbon dioxide as activator. Effects of CO2 flux, activation time and temperature on the yield and adsorption property of activated carbon were studied with orthogonal experimentation. The proper conditions were： 800℃, 30 rain, CO2 flux： 3L/rain, and the yield was 9. 47%. The product＇ s sorption values for iodine and methylene blue were 1079.26mg/g and 67.5mg/g, respectively. The nitrogen adsorption isothermal curve of the activated carbon was determined and its pore structure was characterized with BET method, H-K equation, D-A equation and theory of density function. The results showed that the obtained activated carbon was of micropore type with BET specific surface area of 761m^2/g, total pore volume of 0. 3521cm^3/g. Of the total pore volume, micropores＇ volume accounted for 95.54% , mesopores＇ volume 3.85% and macropores＇ volume 0.61%. The microstructure of the activated carbon was sion electronic microscopy, the results were comparable analyzed by electronic microprobe and transmiswith that determined by nitrogen adsorption.