Modification of montmorillonite clay for the selective sorption of argon mixed with oxygen

Abstract

The purpose of this study was to determine optimal conditions for the synthesis of adsorbent based on montmorillonite clays for the selective adsorption of argon from its mixture with oxygen. To determine the conditions for modification of the samples was used the method of experiment planning. The independent factors were chosen: the ratio Al³⁺/OH^-; the temperature of ion exchange; the drying temperature; the calcinations temperature; the ratio Al³⁺/Cr³⁺_. The area values were as follows: the ratio Al³⁺/OH^- 1:2.0–1:2.4; the temperature of ion exchange 25–75°С; ; the drying temperature 25–85°С; the calcinations temperature 400–550°С; the ratio Al³⁺/Cr³ 0–1. Parameter optimization was the separation factor a gas mixture of argon-oxygen, which is calculated as the ratio of the equilibrium adsorption capacity of argon and oxygen. The paper presents the elemental composition, structural and energy characteristics and data on the adsorption of argon and oxygen on prepared samples. The optimal parameters of medication clays: the ratio Al³⁺/OH^- 1:2.0–1:2.0; the temperature of ion exchange 75°С; ; the drying temperature 25°С; the calcinations temperature 550°С; the ratio Al³⁺/Cr³ 0. The result of pillaring in optimum conditions was obtained the Al-PILC sample with equilibrium adsorption of oxygen and argon 4.50 and 6.70 cm³/g, respectively; the separation factor was 1.5.