Adsorption of carbon dioxide on hydrotalcite-like compounds of different compositions
Adsorption of carbon dioxide on hydrotalcite-like compounds of different compositions
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DOI：
10.1016/j.cherd.2010.09.019
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发表时间：
2011-09-01
影响因子：
3.9
通讯作者：
Wood, Joseph
中科院分区：
文献类型：
--
作者：
Aschenbrenner, Ortrud;McGuire, Paul;Wood, Joseph
研究了类水滑石对二氧化碳的吸附性能。使用两种不同的粉末状水滑石，其含有阳离子镍和铁。使用热重法筛选粉末材料的二氧化碳吸附，发现NiMgAl（样品1）水滑石具有最大的CO2容量，在20 ℃下吸附1.58 mmol g（-1），最高吸附速率高达0.17 mmol g（-1）min（-1）。这表示与NiMgAlFe（样品2）相比，吸附容量增加了53%。为了改善用于挤出的水滑石糊剂的流变行为，将水滑石粉末与勃姆石氧化铝（水滑石：勃姆石的比例为70：30和50：50）混合，然后挤出成适用于固定床吸附器的粒料。然后将这些粒料再粉碎并通过热重法进一步测试。研究了温度、组成及预处理对水滑石吸附二氧化碳和氮气的影响。在20 ℃时，本研究中所有水滑石/氧化铝样品的二氧化碳吸附量在2.0和2.5 mmol g（-1）之间，尽管随着温度的升高，二氧化碳吸附量迅速衰减。结果与硅胶作为一种常见的吸附剂参考，并与文献值进行了比较。水滑石/氧化铝样品具有热稳定性和在宽温度范围内对二氧化碳的高吸附容量。在这项研究中调查的水滑石/氧化铝颗粒的组合物的吸附行为的影响较小，与非煅烧的水滑石粉末相比，从而允许广泛的选择使用的颗粒组合物。(C)2010年，化学工程师学会。Elsevier B. V.出版，保留所有权利。
The adsorption of carbon dioxide on hydrotalcite-like compounds was investigated. Two different powdered hydrotalcites were used containing the cations nickel and iron. The powdered materials were screened for carbon dioxide adsorption using a thermogravimetric method and it was found that NiMgAl (Sample 1) hydrotalcite has the largest capacity for CO2, adsorbing 1.58 mmol g(-1) at 20 degrees C, and highest rate of adsorption of up to 0.17 mmol g(-1) min(-1). This represented an increase of 53% in adsorption capacity, compared with NiMgAlFe (Sample 2). In order to improve the rheological behaviour of hydrotalcite paste for extrusion, hydrotalcite powders were combined with boehmite alumina (70:30 and 50:50 ratios of hydrotalcite:boehmite) before extrusion into pellets suitable for use in a fixed bed adsorber. These pellets were then re-crushed and further tested by thermogravimetric methods. The effects of temperature, composition and pre-treatment of the hydrotalcites on the adsorption of carbon dioxide and nitrogen are reported. At 20 degrees C, the amount of carbon dioxide adsorbed was between 2.0 and 2.5 mmol g(-1) for all the hydrotalcite/alumina samples in this study, although this decayed rapidly with increasing temperature. The results are compared with silica gel as a common sorbent reference, and with literature values. Hydrotalcite/alumina samples have thermal stability and a high adsorption capacity for carbon dioxide over a wide range of temperatures. The composition of the hydrotalcite/alumina pellets investigated in this study has less effect upon the adsorption behaviour compared with the non-calcined hydrotalcite powder, thus allowing a wide choice of pellet compositions to be used. (C) 2010 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.