Effect of the Membrane Quality on Gas Permeation and Chemical Vapor Deposition Modification of MFI-Type Zeolite Membranes
Effect of the Membrane Quality on Gas Permeation and Chemical Vapor Deposition Modification of MFI-Type Zeolite Membranes
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DOI：
10.1021/ie101101z
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发表时间：
2010-09
影响因子：
4.2
通讯作者：
Xuefeng Zhu;Haibing Wang;Y. S. Lin
中科院分区：
文献类型：
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作者：
Xuefeng Zhu;Haibing Wang;Y. S. Lin
甲基二乙氧基硅烷（MDES）化学气相沉积（CVD）法降低MFI型分子筛孔径是提高分子筛膜H2/CO2分离性能的有效途径。然而，只有晶间缺陷较少的良好膜才能通过CVD改性显着改善H2/CO2分离因子。基于H2/SF6或N2/SF6理想分离因子评价膜质量是不可靠的，因为SF6吸附诱导的晶体溶胀导致MFI沸石膜中晶间缺陷的收缩。在这项研究中，质量的MFI沸石膜的基础上，在室温下分离等摩尔H2/CO2混合气体的性能进行了评价。高质量的膜在室温下对CO2分子比对H2分子更有选择性，这是由于CO2被吸附到沸石孔中并阻塞了用于H2扩散的孔道。现场试验结果证实了该质量评价方法的有效性。
Chemical vapor deposition (CVD) with methyldiethoxysilane (MDES) for MFI zeolitic pore size reduction is an effective way to improve the H2/CO2 separation factor of zeolite membranes. However, only good membranes with few intercrystalline defects are able to show considerable improvement in H2/CO2 separation factor through CVD modification. It is unreliable to evaluate the membrane quality on the basis of the H2/SF6 or N2/SF6 ideal separation factor because the SF6 adsorption-induced crystal swelling causes shrinkage of the intercrystalline defects in the MFI zeolite membranes. In this study, the quality of MFI zeolite membranes was evaluated on the basis of their performance in separating equimolar H2/CO2 mixture gas at room temperature. High-quality membranes are more selective to CO2 molecules rather than H2 at room temperature due to the adsorption of CO2 into the zeolitic pores and blocking of the pore channels for H2 diffusion. The effectiveness of the quality evaluation method was confirmed by on-s...