不同预植晶种法制备NaA分子筛膜及其表征

Synthesis and characterization of NaA zeolite membrane prepared by different pre-seeding methods

采用多种预植晶种法在管状ɑ-Al2O3外表面水热晶化制备NaA分子筛膜.使用XRD、SEM对合成的膜层进行形貌表征,并用渗透气化技术考察膜的醇水分离性能.结果表明,采取搽涂-浸渍法在支撑体表面预植晶种,并进行2次4h水热晶化成膜制备的膜性能最好,在343K进料液中乙醇质量分数为90%时分离因子与渗透通量分别为6824和1.40kg/(m2·h).并考察操作温度以及料液水含量对膜渗透汽化分离性能的影响.随料液中水含量的增加,分离因子先升高后下降,渗透通量呈增大趋势;随着操作温度升高,分离因子逐渐降低而渗透通量随之增加.

NaA zeolite membranes were hydrothermally prepared by various pre-seeding methods on the outer surface of porous tubular support. The apparent morphology and dehydration performance of the as- sythesized membrane were characterized by X-ray diffraction （XRD）, field emission scanning electron microscopy （FE-SEM） and pervaporation. High-quality membrane was hydrothermally synthesized twice for 4 h with support seeded with NaA zeolite by the combination of rubbing and dipping, which showed a permeation flux of 1.40 kg/（m^2- h） and separation factor of 6 824 for 90 ： 10（mass） EtOH/HzO mixture at 343 K. The effect of operating temperature and feed concentration on pervaporation performance were also studied. The results show that with feed water concentration rising, the permeation flux declines while the separation factor increases initially then declines. When increasing the operating temperature, the separation factor declines slightly while the permeation flux increases.