摘要
以烟杆为原料,以氯化锌为活化剂,采用一步炭化活化法制备了活性炭。采用正交实验研究了氯化锌浓度、浸渍时间、炭化温度和保温时间对活性炭得率和吸附性能的影响,最佳工艺条件为ZnCl2浓度25%,浸泡时间12h,炭化温度650℃,保温时间20min时,所制造的活性炭其碘吸附值为1080.36mg/g,亚甲基蓝吸附值为170.0mL/g,得率为36.00%。同时测定了该活性炭的液氮吸附等温线,并通过BET、H-K方程、D-A方程和密度函数理论(DFT)表征了活性炭的孔结构。结果表明:该活性炭为微孔型,BET比表面积为1476m2/g,总孔容为0.5798mL/g,微孔孔容达到了0.3498mL/g,微孔容积占总孔容的59.83%,中孔占39.51%,大孔占0.66%。
A series of activated carbons were prepared with tobacco stems as r aw materials and zinc chloride as activating agent using a one- step carbonizat ion procedure. The effects of impregnating time and concentration of zinc chlori de solution, carbonization temperature and holding time on the yield and adsorpt ion properties of activated carbon were systematically studied via orthogonal ex periments. Through primary study of the reaction mechanism of activated carbon p reparation, the optimum condition has been obtained as follows: concentration of zinc chloride solution is 25% and impregnated time is 12 h while carbonizatio n temperature is 650 ℃ with holding time being 20 min. Thus the experimental r esults have shown that the yield of the activated carbon was 36.00% when the m ethylene blue adsorption reached 17 0.0 mL/g and iodine value was 1 080.36 mg/g. Furthermore, the activated carbon manufactured under optimum condition was test ed by nitrogen adsorption at 77 K. The specific surface area of activated carbon is 1 476 m 2/g by BET method. The porous structures of the activated carbon were investigated by Horvath- Kawazoe equations, Dubinin- Astakhov equations and Density Function Theory. Results show that the activated carbon is microporous with 0.5798 mL/g for total pore volume, the total pore vo lume of 59.83% for micropore volume and 39.51% for mecropore volume and 0.66 % for macropore volume.
出处
《炭素技术》
CAS
CSCD
2005年第3期14-19,共6页
Carbon Techniques
基金
国家自然科学基金资助项目(20167001)
关键词
活性炭
氯化锌
孔径分布
吸附等温线
Activated carbon
zinc chloride
pore size distribution
ads orption isotherm
