MFI型分子筛膜的制备及表征

采用无模板剂的二次生长合成方法,在-αA l2O3基膜上合成了MFI型分子筛膜,用XRD,SEM和气体渗透实验等方法进行表征,表明合成在-αA l2O3基膜的物质为MFI型分子筛。二次生长分子筛膜的正/异丁烷理想分离系数在298 K和473 K时分别为77和70,气体分离数据表明,2种分子筛膜对气体分离是由分子筛分占主导,同时分子筛膜完整无裂缺。不同温度,通过MFI分子筛膜渗透汽化分离质量分数分别为5%、50%和95%的乙醇/水的渗透通量和分离因子,结果表明渗透通量随温度的升高而升高,而分离因子随温度的升高却降低;渗透通量随乙醇质量分数的升高而降低,分离因子却随质量分数的升高而升高。

Preparation and gas permeation properties of MFI-type zeolite membrane

MFI-type zeolite membranes were prepared on α-Al_2O_3 substrate by secondary growth synthesis without template.XRD,SEM and gas permeation experiments were applied to characterize the zeolite membrane.Ideal separation factors of n-butane/i-butane on MFI-type zeolite membrane by secondary growth synthesis are up to 77 and 70 respectively at 298 K and 473 K.The data of gas separation indicated that the separation was dominated by molecular sieving mechanism on two zeolite membranes free of defects.The separation factors of the EtOH/H_2O solutions with the EtOH mass fraction of 5%,50% and 95% on MFI zeolite membranes were obtained by pervaporation at different temperatures.The results show that when increasing temperature the permeances of EtOH/H_2O increase and the separation factors decrease;and the permeances decrease and the separation factors increase with the increase of mass fraction of EtOH.