NaY沸石膜的合成及用于渗透汽化分离苯-环己烷

采用热浸渍法引入晶种,通过二次生长在α-Al2O3陶瓷管的外表面上合成了NaY沸石膜。利用X射线衍射和扫描电子显微镜对沸石膜进行了表征。表征结果显示,合成的膜为NaY沸石膜,膜表面平整、均匀,晶体处于挛生状态,膜厚为10~15μm。将NaY沸石膜用于渗透汽化分离苯-环己烷,考察了操作条件对分离效果的影响。实验结果表明,NaY沸石膜对苯具有良好的选择性,对于苯质量分数为50%的苯-环己烷物系,操作温度为70℃时,分离因子可达13,渗透通量为0.082kg/(m2.h)。

Synthesis of NaY Zeolite Membrane for Separation of Benzene-Cyclohexane by Pervaporation

NaY zeolite membranes were synthesized on outer surface of α-Al2O3 ceramic tube by hot impregnation for introducing seed crystal and successive crystallization one cycle after the other. The synthesized membranes were characterized by means of XRD and SEM. Structure of the synthesized membrane is of NaY zeolite, its surface is smooth and its thickness is in range of 10-15 μm after 4 cycles of hot impregnation and following crystallization. The synthesized NaY zeolite membranes were used to separate the mixture of benzene and cyclohexane by pervaporation. Effects of temperature and benzene content in feed on pervaporation were studied. The NaY zeolite membrane shows good benzene permselectivity in pervaporation of benzene-cyclohexane system. For benzene-cyclohexane system with mass fraction of benzene 50%, separation factor of the membrane is 13 and permeation flux is 0.082 kg/(m2·h) at operation temperature of 70 ℃.