| 莫来石管上丝光沸石膜的合成与渗透汽化性能 | |
| Synthesis and Pervaporation Performance of Mordenite Membranes on Mullite Tubes | |
| 摘要: 采用不添加有机模板剂、配比为nNa2O∶nAl2O3∶nSiO2∶nH2O=0.25∶0.015~0.1∶1∶15~60溶胶，在涂有晶种的多孔莫来石管上水热合成出了丝光沸石膜。制备的膜经XRD和SEM表征。考察了合成时间、硅铝比、水硅比和硅源等因素对膜生长及其性能的影响。合成时间的延长有利于丝光沸石c轴方向的优先生长，然而优先取向生长膜层并未提高膜在水/乙醇分离体系中的渗透通量和选择性。优化条件下合成的膜具有较高的渗透汽化性能，在348 K、水/乙醇(10/90，W/W)混合溶液中的渗透通量和分离因子分别为0.70 kg·m-2·h-1和860。基于XRD和SEM表征结果，高的渗透汽化性能可归结于在莫来石支撑层与较为疏松的表面晶体层之间形成的致密中间层。 | |
| 关键词: 沸石膜 丝光沸石 水热合成 渗透汽化 | |
| 基金项目: | |
| Abstract: Mordenite membranes were synthesized on porous mullite tubes by secondary growth method using a template-free aluminosilicate gel with molar compositions of nNa2O∶nAl2O3∶nSiO2∶nH2O=0.25∶0.015~0.1∶1∶15~60. The as-synthesized mordenite membranes were characterized by x-ray diffraction(XRD) and scanning electron microscope(SEM). The effects of synthesis conditions such as synthesis time, nSiO2/nAl2O3 ratio, nH2O/nSiO2 ratio, and silica source on the crystallization and the pervaporation(PV) properties of zeolite layers were investigated. The increase in synthesis time could accelerate the formation of mordenite membranes preferentially oriented with c axis normal to the support surface. However, the oriented mordenite top layer does not improve the flux and selectivity toward a water/ethanol mixture by PV. Under optimized reaction conditions, the as-synthesized membrane shows high PV performance with a flux of 0.70 kg·m-2·h-1 and separation factor of 860 for a feed of 10wt% water/ethanol mixture at 348 K. The high PV performance could be contributed to the compact intermediate zeolite layer between the support layer and top layer based on the results of XRD and SEM characterization. | |
| Keywords: zeolite membrane mordenite hydrothermal synthesis pervaporation | |
| 摘要点击次数: 1235 | |
| 全文下载次数: 1751 | |
| 周荣飞,李 军,朱美华,胡中丽,段龙乔,陈祥树.莫来石管上丝光沸石膜的合成与渗透汽化性能[J].无机化学学报,2010,26(3):469-475. | |
| 查看全文 查看/发表评论 下载PDF阅读器 | |
| Support information: | |
|
| |
|
| |
|
| |