定向含硼MFI型沸石膜对纯气体的渗透性以及对乙醇/水体系的分离选择性

Permeabilities of Pure Gases and Separation Selectivities of Ethanol/Water Systems through Oriented B-containing MFI-type Zeolite Membranes

研究定向含硼MFI型沸石膜和原多孔玻璃基材对纯气体的渗透性以及对乙醇 /水体系的分离选择性 .原多孔玻璃基材对纯气体的透过表现出诺森扩散选择性 ,表明气体以诺森扩散通过 .纯气体透过焙烧后的B Al ZSM 5沸石膜 ,H2 ,He ,Ne ,Ar ,O2 ,CO2 对N2 的理想选择性分别为 16 8,15 6,12 6,9 41,8 60 ,5 3 2 ;CO和SO2 对N2 的理想选择性分别为0 13 5和 0 0 179;O2 对CO和SO2 的理想选择性分别为 63 7和 480 2 .这表明该类沸石膜对纯气体的透过不仅具有良好的理想选择性 ,而且可能为新型防毒面具提供一种很好的可选材料 .渗透汽化实验表明 ,在测定温度范围内原多孔玻璃基材对三种不同浓度的乙醇 /水体系几乎没有分离性能 .焙烧后的B Al ZSM 5沸石膜对 5wt % ,5 0wt%和 95wt%乙醇 /水体系的分离 ,水的最大分离系数分别为 2 8 2 ,13 5 7和 5 18 5 ,且温度均为 3 0 3K .

Permeabilities of pure gases and separation selectivities of ethanol/water systems through the oriented B-containing MFI-type zeolite membranes and the initial porous glass disks were studied. The initial porous glass disks displayed the selectivities of Knudsen diffusion for the permeating of pure gases, showing that the gases penetrated through the initial substrates by Knudsen diffusion. On the calcined zeolite membranes, the ideal selectivities of H-2, He, Ne, Ar, O-2 and CO2 over N-2 are 16.8, 15.6, 12.6, 9.41, 8.60 and 5.32, CO and SO2 over N-2 are 0.135 and 0.0179, respectively. However, the ideal selectivities of O-2 over CO and SO2 reach 63.7 and 480.2, respectively. The fact shows that the calcined zeolite membranes not only possess better ideal selectivities for the permeation of pure gases, but also can serve a; the good alternative for making novel gas masks. On pervaporation, the initial porous glass disks display neatly no separation performance to all the three solutions within the measured temperatures. The highest water separation factors appearing at 303 K are 28.2, 135.7 and 518.8 for the solutions of 5 wt%, 50 wt% and 95 wt% EtOH/H2O at different temperatures, respectively, indicating that the prepared membranes are strongly hydrophilic.