Preparation And Separation Characteristics Study Of Zeolite T Membrane

In this thesis, high performance zeolite T menbrane on macro-porous supports was prepared by secondary method.The effects of seeding layer, synthesis conditions, fluoride optimization on morphology, pervaporation and segregational stability were investigated. The formation mechanism of zeolite T menbrane and the preparation routes under fluoride media were explored. The membrane in fluoride media showed an excellent acid resistance compared with non-fluoride synthesis system. The main conclusions obtained in the thesis were as follows:(1).Different sized of zeolite T with 400nm,600nm,2?m were synthesized by changing synthesis condition with the formulation 18.2SiO2:lAl2O3:4.2Na2O:1.5K2O:212.7H2O: 0.82TMAOH.The influence of synthesis conditions were investigated.(2).Zeolite T membrances were prepared on the low price macroporous ?-Al2O3 tubular support at 120 ? for 16 hours by secondary growth. The effects of the concentration of seeds and the membrane growth time on the morphology and pervaporation properties of membrane have been investigated. The performance of as-synthesized membranes for 90wt.%IPA/H2O mixture was high with the total flux up to 2.96 kg·m-2·h-1 and the separation factor of 6400.(3).The formation mechanism of zeolite T menbrane was explored. The results of XRD and SEM showed that the crystallization period was largely shortened to 16 h due to the secondary nucleation induced by the seeds and the epitaxial growth of the seeds.(4).The influence of synthesis conditions under fluoride media on morphology and pervaporation of the synthesized membranes were investigated. The membrane in fluoride media showed an excellent acid resistance compared with non-fluoride synthesis system. The formation of the acid nonresistant film microstructures in conventional synthesis, such as gain boundaries, have been effectively avoided by the optimization of the distribution of Si, Al atoms in zeolite film.