清液体系高性能T型分子筛膜的制备及表征

摘要

采用二次生长法，在廉价大孔α-Al2O3管状载体上通过变温热浸渍涂晶法获得连续致密的晶种层，在摩尔配比为1SiO2：0.05Al2O3：0.26Na2O：0.09K2O：30H2O清液体系中120℃水热晶化16 h成功制备出T型分子筛膜。实验考察了小晶种液浓度，晶化时间对T型沸石分子筛膜的形貌和性能的影响。XRD和SEM结果表明，晶化过程中晶种的外延生长和新的晶核成核过程同时进行，晶种的外延生长和新核的诱导作用产生协同作用，缩短 T 型沸石膜的生长时间。将制备的T型沸石分子筛膜用于75℃渗透汽化分离10wt%水/异丙醇体系，其渗透通量和分离系数分别达到2.96 kg/(m2·h)和6400。%T-type zeolite membrances with high permeation performance were successfully synthesized on the low cost macroporousα-Al2O3 tubular support by secondary growth from clear solutions. The effects of the con-centration of seeds and the membrane crystallization time on the morphology and pervaporation properties of zeo-lite T membrances. When the molar ration of the synthesis solution was 1SiO2:0.05Al2O3:0.26Na2O:0.09K2O: 30H2O, a high quality T zeolite membrane was obtained at crystallization temperature of 120℃ for 16 h, with water flux of 2.96 kg/(m2·h) and separation factor of 6400 for dehydration of IPA aqueous solution by pervaporation at 75℃. XRD pattern and SEM observation suggested that the shortened membrane crystallization time resulted from the secondary nucleation induced by the seeds and the seeds epitaxial growth.