B-ZSM-5沸石分子筛膜的制备及正/异丁烷分离性能

Preparation of B-ZSM-5 Membrane for Butane Isomer Separation

采用两次变温热浸渍法在大孔α-Al_(2)O_(3)多孔管状载体外表面涂覆B-ZSM-5大小晶种,以制备平整、连续且致密的B-ZSM-5晶种层,随后在晶化成膜液的稀溶液体系下,利用二次生长法在α-Al_(2)O_(3)管外表层成功制备B-ZSM-5沸石分子筛膜。实验采用扫描电子显微镜(SEM)和X射线衍射仪(XRD)对B-ZSM-5沸石分子筛膜的形貌和结构进行了表征,同时利用气体渗透测试装置分别测试了其对H_(2)、N_(2)、CH_(4)、n-C_(4)H_(10)、i-C_(4)H_(10)的气体渗透速率,并探究了温度对n-C_(4)H_(10)/i-C_(4)H_(10)异构体分离的影响。研究结果表明,B-ZSM-5沸石分子筛膜对n-C_(4)H_(10)/i-C_(4)H_(10)异构体分离具有较好的分离效果,在200℃、0.125 MPa下,B-ZSM-5沸石分子筛膜对n-C_(4)H_(10)/i-C_(4)H_(10)异构体的理想分离系数达104.73,对n-C_(4)H_(10)和i-C_(4)H_(10)的气体渗透速率分别为5.98×10^(-8)和5.71×10^(-10)mol·m^(-2)·s^(-1)·Pa^(-1)。

B-ZSM-5 membrane was prepared on the outer surface of α-Al_(2)O_(3) support from dilute solution system of crystallization film forming solution by the secondary growth method. The morphology and structure of B-ZSM-5 membrane were characterized by scaning electron microscope and X-Ray Diffratometer. At the same time, gas permeation rates of H_(2), N_(2), CH_(4), n-C_(4)H_(10) and i-C_(4)H_(10) were measured by gas permeation apparatus, respectively. The effect of temperature on the separation of n-C_(4)H_(10)/i-C_(4)H_(10) isomers was investigated. The results showed that the as-prepared B-ZSM-5 membrane exhibited good separation performance for n-C_(4)H_(10)/i-C_(4)H_(10) isomers. The gas permeation rates of n-C_(4)H_(10) and i-C_(4)H_(10) were 5.98×10^(-8) and 5.71×10^(-10 )mol·m^(-2)·s^(-1)·Pa^(-1), respectively. The corresponding ideal separation coefficient is up to 104.73.