2～5nm孔集中分布泥炭基中孔活性炭的制备  

Preparation of mesoporous peat-based activated carbon with peak distribution of 2—5 nm pores

作　　者：邓锋[1,2] 解强 刘德钱[1] 万超然 黄小晴 顾雪梅 DENG Feng;XIE Qiang;LIU Deqian;WAN Chaoran;HUANG Xiaoqing;GU Xuemei(School of Chemical and Environmental Engineering,China University of Mining&Technology(Beijing)),Beijing 100083,China;The Coal Chemical Engineering Collaborative Innovation Center of Guizhou Province,Guizhou University of Engineering Science,Bijie 551700,Guizhou,China)

机构地区：[1]中国矿业大学(北京)化学与环境工程学院,北京100083 [2]贵州工程应用技术学院贵州省煤化工工程协同创新中心,贵州毕节551700

出　　处：《化工学报》2019年第11期4457-4468,共12页CIESC Journal

基　　金：贵州省教育厅青年科技人才成长项目(黔教合KY字[2018]392);贵州省科学技术基金项目(黔科合LH字[2014]7524号)

摘　　要：将泥炭破碎、粉磨、浸渍磷酸后,压块成型、再破碎,置于管式炉经不同活化温度、活化时间制得活性炭。对浸渍磷酸后的泥炭样品在氮气下进行热重分析;测定活性炭样品的碘吸附值、亚甲蓝吸附值和焦糖脱色率,利用气体吸附仪、激光拉曼光谱、傅里叶变换红外光谱和扫描电子显微镜分别表征其孔结构、碳结构、表面化学和微观形貌。结果表明:泥炭在磷酸活化过程中发生了交联反应,炭化/活化最大失重温度从300℃附近降低至200℃附近;随着磷酸浸渍比和活化温度的升高,活性炭中的无规则石墨层增多、羟基含量减少;磷酸浸渍比增加时,孔隙逐渐发达、吸附性能增强、2-5 nm孔段孔容增大;活化温度升高时,孔隙先收缩(400-550℃)后发生破坏(600℃)、吸附性能下降、2-5 nm孔段孔容减小;随着活化时间延长,活性炭的羟基含量先大幅减小(120-150 min)后无规律变化,孔隙先扩大(120-180 min)后收缩(>180 min),吸附性能>180 min后迅速下降,碳结构和2-5 nm孔段孔容无显著变化。在磷酸浸渍比1.5、活化温度500℃、活化时间180 min条件下,制得活性炭的比表面积为678.52 m2·g^-1,2-5 nm孔段的孔容达0.1475 cm3·g^-1、占总孔容比率为31.04%、占中孔容比率为70.24%。Peat was sampled, crushed, ground, impregnated with H3PO4, briquetted and re-crushed, then a series of activated carbon samples were prepared by activation in tube furnace at different temperature and time.Thermogravimetric analysis of H3PO4 impregnated peat samples were performed in a nitrogen environment. The adsorption capacity indexes including iodine value, methylene blue value and caramel decolorization rate were determined, and pore structure, carbonaceous structure, surface chemistry and micro morphology of activated carbon samples were characterized by gas adsorption instrument, Raman spectroscopy, infrared spectrum and scanning electron microscope, respectively. The results show that peat is cross-linked during phosphoric acid activation, and the maximum mass-loss temperature of carbonization/activation drops from around 300℃ to ca.200℃. With the increase of H3PO4 impregnation ratio and activation temperature, content of irregular graphitic layers in activated carbon increases, and hydroxyls groups on surface of activated carbon decreases. The increase of H3PO4 impregnation ratio results in gradual increase of pore development, absorption performance and volume of2-5 nm pores. And the increase of activation temperature results in shrink firstly(at 400-550℃) and then destroy(at 600℃) of pore structure, decrease of absorption performance and volume of 2-5 nm pores. With the increase of activation time, the content of hydroxyl groups on surface of activated carbon firstly reduces greatly(during 120-150 min) and then undergoes irregular changes, meanwhile, the pores firstly expand(during 120-180 min) and then shrink(>180 min), and the absorption performance reduce rapidly after 180 min, at the same time the carbonstructure and the volume of 2-5 nm pore section don.t show significant change. An activated carbon with a specificsurface area of 678.52 m2·g^-1, volume of 2-5 nm pores of 0.1475 cm3·g^-1, accounting for 31.04% of the total porevolume and 70.24% of the mesopore volume, can be derived unde

关 键 词：泥炭 活性炭 磷酸 活化作用 二 英 烟道气 

分 类 号：TQ424.1[化学工程]