Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
632634 | Journal of Membrane Science | 2016 | 6 Pages |
Abstract
The permeability and separation ability of zeolite membranes correspond to the micropore volume and channel diameter of zeolites, respectively. Since the AEI-type zeolite possess a large pore volume (0.28Â mLÂ gâ1) and small channel diameter (0.38Â nm), they can potentially be used as membrane materials. In this study, a polycrystalline AEI-type zeolite layer was formed on a porous support tube by means of secondary growth, and the physicochemical properties of the membrane were characterized using SEM, EDX, XRD, and TG-DTA. Furthermore, the dehydration performance of the membrane was determined by pervaporation for an equimolar mixture of water and ethanol at 313Â K. It was determined that the water/ethanol flux ratio was 10,000 before structure-directing agent (SDA) removal, although defect-free membranes could not be obtained. Zeolite micropores were formed by air calcination at temperatures above 523Â K. However, the SDA could not be removed completely at temperatures between 523 and 673Â K. Moreover, the separation performance of the calcined membrane decreased due to the change in the unit cell parameters owing to SDA removal. These results suggest that the expansion and/or distortion of the unit cell after the SDA removal creates larger defects at the grain boundaries of the crystals.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Filtration and Separation
Authors
Yasuhisa Hasegawa, Chie Abe, Takuji Ikeda, Koichi Sato,