Activated carbons by pyrolysis of coffee bean husks in presence of phosphoric acid
Activated carbons by pyrolysis of coffee bean husks in presence of phosphoric acid
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DOI：
10.1016/s0165-2370(02)00180-8
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发表时间：
2003-12-01
影响因子：
6
通讯作者：
Tascón, JMD
中科院分区：
文献类型：
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作者：
Baquero, MC;Giraldo, L;Tascón, JMD
以咖啡豆壳为原料，在磷酸存在下热解制备了活性碳(AC)。哥伦比亚咖啡豆的外壳被浸泡在H3PO4的水溶液中，方法是采用一种变种的初始湿法。使用不同的浓度来产生30、60、100和150wt.%的浸渍比。活化是在充气条件下进行的，加热到723K，浸泡时间为1h。通过在77K和273K时对N-2和CO2的物理吸附表征了所得到的AC的孔结构。浸渍比对这些AC的孔结构有很大的影响，只需改变活化过程中使用的H3PO4的比例就可以很容易地控制孔结构。因此，较低的浸渍比导致了基本上微孔的ACS。在中等浸渍比下，可以得到孔径分布较宽(从微孔到中孔)的AC。最后，较高的浸渍比制得的中孔炭具有较高的比表面积和孔容。(C)2002 Elsevier Science B.V.保留所有权利。
Activated carbons (Acs) were prepared by pyrolysis of coffee bean husks in presence of phosphoric acid (chemical activities). Husks from Colombian coffee beans were impregnated with aqueous solutions of H3PO4 following a variant of the incipient wetness method. Diffenent concentrations were used to produce impregnation ratios of 30, 60, 100 and 150 wt.%. Activation was carried out under argon flow by heating to 723 K with 1 h soaking time. The porous texture of the obtained ACs was characterized by physical adsorptions of N-2 at 77 K and CO2 at 273 K. The impregnation ration had a strong influence on the pore structure of these Acs, which could be easily controlled by simply varying the proportion of H3PO4 used in the activation. Thus, low impregnation ratio led to essentially microporous Acs. At intermediate impregnation ratios, ACs with wider pore size distribution (from micropores to mesopores) were obtained. Finally, high impregnation ratios yielded essentially mesoporous carbons with high surface area and pore volume. (C) 2002 Elsevier Science B.V. All rights reserved.