Preparation of high-permeance MFI membrane with the modified secondary growth method on the macroporous α-alumina tubular support
Preparation of high-permeance MFI membrane with the modified secondary growth method on the macroporous α-alumina tubular support
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DOI：
10.1016/j.memsci.2008.04.035
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发表时间：
2008-07
影响因子：
9.5
通讯作者：
Qingyu Zhao;Jinqu Wang;Naibo Chu;Xiaoyan Yin;Jianhua Yang;Chunlong Kong;Aifang Wang;Jinming Lu
中科院分区：
文献类型：
--
作者：
Qingyu Zhao;Jinqu Wang;Naibo Chu;Xiaoyan Yin;Jianhua Yang;Chunlong Kong;Aifang Wang;Jinming Lu
采用改进的二次生长法在大孔（孔径3-4μm）α-Al 2 O3管状载体上成功制备了高透过率的MFI膜。在晶化之前，用聚四氟乙烯带包裹晶种载体，以使晶体生长集中在晶种层区域。采用X射线衍射（XRD）、扫描电镜（SEM）和单气体渗透测试等手段对膜进行了表征。结果表明，该膜的厚度为6-8μm，与种子层的厚度相近，具有较高的气体透过性能。在室温下，H2的渗透率和H2/SF6的理想分离因子分别达到1.64×10− 6 molm −2s− 1 Pa − 1和71。单一气体的渗透率随温度的升高而增大。在298 ~ 473 K范围内，H2/i-C4 H10和H2/SF6的理想分离因子随温度的升高而降低。在473 K时，H2/i-C4 H10和H2/SF6的理想分离因子分别为12.16和11.08，仍高于它们的努森比5.39和8.54。
MFI membrane with high permeance was successfully synthesized on the macroporous (pore size of 3–4μm) α-Al2O3tubular support with a novel modified secondary growth method. Before the crystallization, the seeded support was wrapped with Teflon tape in order to focalize the growth of crystals in the region of seed layer. The as-synthesized membrane was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and single-gas permeation testing. The results indicated that the as-synthesized membrane had a thickness of 6–8μm similar to the thickness of the seed layer and exhibited high gas permeance. At room temperature, the permeance of H2and the ideal separation factor of H2/SF6reached 1.64×10−6molm−2s−1Pa−1and 71, respectively. The permeance of single-gas increased with the increasing of temperature. The ideal separation factors of H2/i-C4H10and H2/SF6decreased with the increasing of temperature from 298 to 473K. At 473K, the ideal separation factors of H2/i-C4H10and H2/SF6were 12.16 and 11.08, which were still higher than their Knudsen ratios of 5.39 and 8.54, respectively.