摘要
以粒径小于6mm的废弃兰炭末为原料,高温下分别用水蒸气和CO2为介质活化制备兰炭基活性炭。采用碘吸附实验、N_2吸附/脱附实验和SEM等手段对成品的孔隙结构进行表征,比较了不同温度下活化介质对成品孔隙形成过程的影响,并分析了活化机理。结果表明:水蒸气活化速率更快,在温度较低时反应就能充分进行。随着活化温度的升高,两种活化介质制备活性炭的碘吸附值先增加后减小,收率均降低;N_2吸附/脱附实验表明,两种吸附等温线均符合I型吸附曲线的特征,成品微孔发达并含有中、大孔,900℃和1 000℃分别是水蒸气和CO_2活化过程的最佳温度,CO_2活化效果更好,成品的微孔比表面积和微孔体积低,平均孔径更大;机理分析表明,随着活化温度上升,先持续发生径向造孔作用,再发生横向扩孔作用,径向活化是活性炭形成发达微孔的主要控制过程。
Blue coke-based activated carbon(BAC)was prepared using disused blue coke powder less than 6 mm as raw materials by activation with steam and CO2 at high temperature.The pore structure of BAC sample was characterized by iodine adsorbed,cryogenic N2 adsorption techniques and scanning electron microscopy(SEM)and the influence of activation medium on formation process of pore was compared.Moreover,the activation mechanism was also tentatively postulated.The results show that the activation rate of steam is faster than that of CO2 because it can be fully carried out at low temperatures.The iodine adsorption value of BACs activated by steam and CO2 increases firstly and then decreases,and the yields all reduce.The N2 adsorption-desorption isotherms revealed that the BACs exhibit type I adsorption isotherms and the material structure consists of microporous and mesoporous.The optimal temperatures of steam and CO2 activation are 900℃and 1000℃respectively.Compared to steam,although the CO2 activation is more effective,the specific surface area and volume of the micropore are lower,and the average pore size is larger.Mechanism analysis shows that with the increase of activation temperature,radial hole-making function occurs firstly and then transverse hole-enlarging occurs.In addition,in order to form a large amount of microporous,the radial activation is the main controlling process.
作者
蒋绪
兰新哲
景兴鹏
宋永辉
邢相栋
JIANG Xu;LAN Xinzhe;JING Xingpeng;SONG Yonghui;XING Xiangdong(School of Metallurgical Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,China;Shaanxi Province Metallurgical Engineering and Technology Research Centre,Xi’an University of Architecture and Technology,710055 Xi’an,China;Research Institute of Energy and Chemical Industry,Xianyang Vocational Technical College,712000 Xianyang,China;Xi’an Research Institute Company Limited,China Coal Technology and Engineering Group,710054 Xi’an,China)
出处
《煤炭转化》
CAS
CSCD
北大核心
2019年第2期65-71,共7页
Coal Conversion
基金
国家自然科学基金资助项目(51774227)
陕西省教育厅专项项目(17JK1170)
咸阳职业技术学院科学技术研究项目(2017KYA02)
关键词
兰炭末
水蒸气
二氧化碳
兰炭基活性炭
活化
blue-coke powder
steam
carbon dioxide
blue coke-based activated carbon
activation
