THE EFFECT OF DEALUMINATION-DESILICATION TREATMENT ON THE POROSITY CHARACTERISTICS OF COMMERCIAL GRANULAR ZEOLITE 13X

In this study, commercial granular zeolite 13X underwent dealumination using chelating agent EDTA and subsequent desilication by the aid of sodium hydroxide solution. Both parent zeolite (PZ) and treated samples (DZ) were characterized by scanning electron microscopy-energy dispersive x-ray (SEM/EDX), nitrogen adsorption-desorption isotherm, Fourier transform infrared (FT-IR) and x-ray diffraction (XRD) analysis techniques. The results indicated that due to low Si to Al ratio of zeolite 13X and the presence of binder used to make granular product from the initial powder zeolite, the consecutive dealumination–desilication post-treatment led to partial damage of micropores without creating new porous systems in the zeolite framework. However, the crystallinity of treated samples from XRD patterns was so better compared to that of parent zeolite. The study suggests that in order to introduce mesoporosity in commercial shaped zeolites, two important parameters i.e. silica to alumina ratio and the presence of the binders would influence the processes.