Preparation of Faujasite membranes and their permeation properties
Preparation of Faujasite membranes and their permeation properties
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DOI：
10.1016/s1383-5866(01)00110-1
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发表时间：
2001-10-01
影响因子：
8.6
通讯作者：
Okamoto, K
中科院分区：
文献类型：
--
作者：
Kita, H;Fuchida, K;Okamoto, K
采用水热法在多孔柱状载体表面生长NaX和NaY分子筛膜。NaX和NaY沸石膜起始凝胶的摩尔组成为：SiO_2/Al_2O_3=3.6~5.3(X)，25(Y)，Na2O/SiO_2=1.2~1.4(X)，0.88(Y)，H_2O/Na_2O=30~50。膜的X射线衍射图由对应于载体和NaX或NaY沸石的峰组成。原子吸收光谱分析表明，NaX和NaY沸石的硅铝比分别为1.3和2.1。扫描电子显微镜(SEM)观察表明，多孔载体的外表面完全覆盖着随机取向、相互生长的NaX或NaY沸石晶体，膜的厚度约为20-30微米。研究了NaY和NaX沸石膜对有机混合物的渗透汽化和蒸气渗透。该分子筛膜对几种进料与甲醇或乙醇的混合物表现出较高的乙醇选择性。此外，苯/环己烷和苯/正己烷的分离具有较高的苯选择性。沸石膜的高选择性可归因于对膜的选择性吸附。(C)2001 Elsevier Science B.V.保留所有权利。
NaX and NaY zeolite membranes were grown hydrothermally on the surface of a porous cylindrical support. The molar compositions of the starting gel of NaX and NaY zeolite membranes were SiO2/Al2O3 = 3.6-5.3 (X), 25 (Y), Na2O/SiO2 = 1.2-1.4 (X), 0.88 (Y), H2O/Na2O = 30-50. X-ray diffraction (XRD) patterns of membranes consist of peaks corresponding to the support and NaX or NaY zeolite. The Si/Al ratio of these NaX and NaY zeolites determined by atomic absorption spectrophotometry was 1.3 and 2.1, respectively. The outer-surface of the porous support was completely covered with randomly oriented, intergrown NaX or NaY zeolite crystals and the thickness of the membrane was about 20-30 mum, judging from the scanning electron microscopy (SEM) observation. Pervaporation and vapor permeation of organic mixtures through NaY and NaX zeolite membranes was investigated. The zeolite membranes showed high alcohol selectivity for several feed mixtures with methanol or ethanol. Furthermore, high benzene selectivity was observed for benzene/cyclohexane and benzene/n-hexane separation. High perm-selectivity of the zeolite membrane can be attributed to the selective sorption into the membrane. (C) 2001 Elsevier Science B.V. All rights reserved.