Permeation of aromatic hydrocarbon vapors through silicalite-zeolite membranes
Permeation of aromatic hydrocarbon vapors through silicalite-zeolite membranes
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DOI：
10.1021/jp960226h
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发表时间：
1996-05-02
影响因子：
--
通讯作者：
Noble, RD
中科院分区：
文献类型：
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作者：
Baertsch, CD;Funke, HH;Noble, RD
在380 K附近，纯芳烃通过硅沸石膜的蒸汽渗透率的相对大小顺序为间二甲苯>对二甲苯>接近甲苯的苯>接近邻二甲苯的苯，渗透率比高达20。这种趋势不遵循动力学直径的大小顺序，因此动力学直径不是渗透的决定因素。芳烃的活化能为13至57 kJ/mol。在二元和三元混合物中，较快渗透的化合物被减慢到与较慢渗透的分子相似的速率，因此对于任何混合物都没有获得分离。这些发现与单行传输一致，其中所有分子都有相同的机会进入孔隙，但它们不能在狭窄的通道中相互通过，并且最慢的物质决定了渗透速率。
Vapor permeances of pure aromatics through silicalite zeolite membranes follow the relative order m-xylene > p-xylene > benzene approximate to toluene > ethylbenzene approximate to o-xylene near 380 K with permeance ratios as high as 20. This trend does not follow the size order of the kinetic diameters, and therefore the kinetic diameter is not the determining factor for the permeation. Activation energies for the aromatics varied from 13 to 57 kJ/mol. In binary and ternary mixtures, the faster permeating compounds were slowed to rates similar to slower permeating molecules, and thus no separation was obtained for any mixture. These findings are consistent with single file transport, where all molecules have equal chances of entering the pores, but they cannot pass each other in the narrow channels and the slowest species determines the permeation rates.