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›› 2005, Vol. 5 ›› Issue (4): 403-406.

• 过程与工艺 • 上一篇    下一篇

小晶粒NaX沸石膜的制备与表征

韩玲,王金渠   

  1. 大连理工大学吸附与无机膜研究所
  • 出版日期:2005-08-20 发布日期:2005-08-20

Preparation and Characterization of Ultrafine Crystal NaX Membrane

HAN Ling,WANG Jin-qu   

  1. Institute of Adsorption and Inorganic Membranes， Dalian University of Technology
  • Online:2005-08-20 Published:2005-08-20

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摘要： 分别以硅溶胶和异丙醇铝为硅源和铝源，采用预涂晶种的方式，用水热合成法在氧化铝载体上合成出小晶粒NaX分子筛膜. 各组分配比为：SiO2:Al2O3=3.85~4.2, Na2O:SiO2=1.2~1.5, H2O:Na2O=40~60，用扫描电镜、Ｘ射线衍射等手段对沸石膜进行了表征，可以看到分子筛膜生长的晶粒细小，沸石晶体的大小在500~800 nm，生长致密良好，覆盖完全，膜厚约为10 mm. 小晶粒NaX沸石膜的H2渗透率为 2.45′10-6 mol×m2/(s×Pa)，H2/N2的理想分离系数达到4.21，H2/C3H8的理想分离系数达到7.56，超过对应的努森扩散值3.74和4.69.

关键词: NaX沸石膜, 水热合成, 晶种

Abstract: Continuous ultrafine crystal NaX membrane was synthesized hydrothermally on the outer surface of a-alumina tube support (12 mm o.d., 8 mm i.d.). Surface-modified tubes were seeded with ultrafine zeolite X crystals prior to the membrane synthesis. The molar composition of the starting gel of NaX membrane was SiO2:Al2O3=3.85~4.2, Na2O:SiO2=1.2~1.5, H2O:Na2O=40~60. The outer surface of the tube was completely covered with zeolite crystals, which were about 500~800 nm in size and about 10 mm in thickness of the membrane as judged by a scanning electron microscope (SEM). The tests on permeation of H2, N2 and C3H8 were carried out to get the ideal separation selectivity of H2/N2 and H2/C3H8 systems. The measured permeability of H2 was about 2.45′10-6 mol×m2/(s×Pa) and the ideal selectivity of H2/N2 and H2/C3H8 was 4.21 and 7.56, which are higher than the respective Knudsen diffusion ratios of 3.74 and 4.69.

Key words: NaX zeolite membrane, hydrothermal synthesis, seeding