Zeolite thermodynamic aspects

Thermodynamic aspects of ionic reactions on inorganic soil constituents (clays, oxides, zeolites, and minerals) have received considerable attention over the years. These studies allow quantification of interactive phenomena, but fail to provide insight into the dynamics, mechanisms, and facets of great importance for construction of effective models. 

Prior to discussing the kinetics of zeolite crystal nucleation and growth it is beneficial to consider several thermodynamic aspects which have bearing on the phase transformation process. Reports on this topic are not abundant in the zeoHte crystallization hterature, but several papers will serve to illustrate various issues which should be important in these systems. 

The aim of this chapter is to present, in a simple and didactic way, the bases of the selective gas adsorption theory and how we can experimentally study the coadsorption of gases by using the calorimetry technique. It focuses on the energetic aspect of adsorption and on the selective physisorption of gases in microporous solids in order to use the selective adsorption for gas separation or gas purification. Thus, the thermodynamics concepts presented in this chapter are illustrated at the end by two experimental case studies on the selective adsorption in faujasite zeolites. The former is devoted to the separation of xylenes isomers, the latter to the desulphurization of natural gas. 

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