Zirconium Pillared Clays for Carbon Dioxide/Methane Separation. 1. Preparation of Adsorbent Materials and Pure Gas Adsorption

Clays intercalated with zirconium oxide having high specific surface areas (up to 270 m2 g-1) were obtained from two Portuguese clays under conditions involving particularly moderated time and temperature, after an optimization of the process of the synthesis where several experimental parameters have been changed. In these pillared clays (PILCs) the adsorption isotherms of carbon dioxide and methane were carried out between 215 and 293 K, and the equilibrium selectivity indicates that they are suitable for the separation of these gases. The vacancy solution theory (VST) was used with success to fit the experimental data, which allows further developments. The prediction of binary isotherms of CO2/CH4 on zirconium pillared clays, as well as some experimental results, will be presented in the second part of this study.