Pore structure and adsorption performance of the KOH-activated carbons prepared from corncob
Pore structure and adsorption performance of the KOH-activated carbons prepared from corncob
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DOI：
10.1016/j.jcis.2005.02.033
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发表时间：
2005-07-15
影响因子：
9.9
通讯作者：
Tseng, SK
中科院分区：
文献类型：
--
作者：
Tseng, RL;Tseng, SK
以450℃玉米芯炭化后的炭为原料，用KOH在780℃下进行化学活化，得到了具有可控表面积的碳质吸附剂。采用基于N-2吸附等温线的t图方法表征了活性炭的比表面积、孔体积、孔径分布和平均孔径等孔隙性质。根据吸附/解吸等温线的类型分为两类。在KOH/char比为0.5 ~ 2的情况下，ⅰ组玉米芯活性炭的BET表面积为841 ~ 1221 m(2)/g。在KOH/char比为3 ~ 6的情况下，第二组玉米芯衍生活性炭的BET比表面积在1976 ~ 2595 m(2)/g之间。扫描电镜（SEM）结果表明，玉米芯活性炭的蜂窝状孔洞表面形貌受KOH/char比的显著影响。研究了两组活性炭在30℃条件下对水中亚甲基蓝、碱性棕1、酸性蓝74、2,4-二氯酚、4-氯酚和苯酚的吸附动力学，并建立了拟一阶和拟二阶简化动力学模型。苯酚和染料在玉米芯衍生活性炭上的有效粒子扩散率高于普通活性炭。高表面积活性炭被证明是一种很有前途的吸附剂，可用于污染控制和其他应用。(c) 2005爱思唯尔公司版权所有。
Carbonaceous adsorbents with controllable surface area were chemically activated with KOH at 780 degrees C from chars that were carbonized from corncobs at 450 degrees C. The pore properties, including BET surface area, pore volume, pore size distribution, and mean pore diameter of these activated carbons, were characterized by the t-plot method based on N-2 adsorption isotherms. Two groups are classified according to the types of adsorption/desorption isotherms. Group I corncob-derived activated carbons, with KOH/char ratios from 0.5 to 2, exhibited BET surface area ranging from 841 to 1221 m(2)/g. Group II corncob-derived activated carbons, with KOH/char rations from 3 to 6, showed high BET surface areas, from 1976 to 2595 m(2)/g. From scanning electron microscopic (SEM) results, the surface morphology of honeycombed holes on corncob-derived activated carbons was significantly influenced by the KOH/char ratios. The adsorption kinetics of methylene blue, basic brown 1, acid blue 74, 2,4-dichlorophenol, 4-chlorophenol, and phenol from water at 30 degrees C were studied on the two groups of activated carbons, which were suitably described by two simplified kinetic models, pseudo-first-order and pseudo- second-order equations. The effective particle diffusivities of phenols and dyes at the corncob-derived activated carbons of group II are higher than those of ordinary activated carbons. The high-surface-area activated carbons were demonstrated to be promising adsorbents for pollution control and for other applications. (c) 2005 Elsevier Inc. All rights reserved.