Adsorption of CO₂, H₂ and CH₄ in natural narrow pore zeolites

The characteristics and results of gas adsorption on a natural zeolite from Escalerillas, San Luis Potosi, Mexico are presented. This material was subjected to various treatment method that improved its texture parameters, adsorption capacity, and also increased the Si/Al atomic ratio in its composition. As a result of these treatments, the adsorption capacity of the zeolite with respect to CH₄ and H₂ has been improved, resulting in higher adsorption heats than those given for some hybrid materials. However, although the natural sample (N) adsorbed more CO₂ at temperatures above 548 K, chemically modified samples showed better behavior at temperatures below 523 K. The different samples obtained were characterized by X-ray diffraction, to determine the crystalline phases present in the structure of the zeolite, as well as to determine to what type of zeolite it belongs when comparing the obtained signals with the database of the International Center for Diffraction Data, compiled in the Powder Diffraction File. (author)