LTA and ion-exchanged LTA zeolite membranes for dehydration of natural gas

•Synthesis and characterization of nanoporous zeolite membranes for gas separation.•Tuning pore of zeolite membranes by ion-exchanging.•Dehydration of natural gas using modified KA zeolite membranes.•XRD, SEM, and EDX characterizations of synthesized LTA membranes.

This work presents synthesis and characterization of LTA-type zeolite membranes on α-Al2O3 substrate via secondary growth method. The membranes were prepared with the aim of applying for dehydration of natural gas. Zeolite NaA membranes were synthesized using hydrothermal method and the pore size of the membranes was then adjusted to 3 Å by ion exchanging the zeolite layer. Potassium chloride (KCl) aqueous solution was utilized as the ion-exchange reagent. The molarity of KCl solution varied from 0.1 to 1 M to figure out the best conditions for the synthesis of KA zeolite membranes. The synthesized membranes were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Energy-dispersive X-ray spectroscopy (EDX). Separation performance of synthesized membranes was evaluated via permeation of water vapor and methane, as a model of natural gas. The results showed that by increasing molarity of KCl solution from 0.1 to 1 M, the permeation of CH4 was reduced. The membranes ion-exchanged in KCl solution with molarity of 0.6 M was chosen as the optimum condition.

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