Encapsulation of Gases in Zeolite 3A and Temperature Programmed Desorption of the Trapped Gases

Abstract

<p>Gases (Ar, N₂ and CO₂) were encapsulated in zeolite 3A at high temperature (350ºC) and pressure (maximum pressure obtained from a gas cylinder). Temperature programmed desorption (TPD), with a linear temperature schedule, was applied to study the kinetics of the release of the trapped gases. The TPD spectra for argon show two peaks ( a large peak at about 350ºC and small one at about 500ºC, for a heating rate of 17ºC per minute) and there is only one peak in the spectra for nitrogen and carbon dioxide. The spectra obtained were analysed using a diffusion equation (Fick's Second Law of diffusion) taking into account the shape and size distribution of the particles. The effect of water addition was shown to enhance the rate of desorption of the trapped gases.</p>