Communication Dans Un Congrès Année : 2025

Roles of cation location in LTA zeolite for methane storage

Résumé

Methane storage is achieved by liquefaction (LNG) or compression (CNG) which are poorly energy efficient processes. Adsorbed Natural Gas (ANG) which consists in a reversible storage of methane in microporous solids under more practical conditions of temperature and pressure has recently found applications. The objective of this work is to investigate zeolites which can adsorb methane but hardly desorb it in order to develop a methane storage solution. From a systematic screening of bicationic LTA zeolite, we discovered two specific compositions, namely K4.2Ca3.9-LTA and Na11K1-LTA which show specific methane adsorption-desorption isotherms. Whereas K-LTA and Ca-LTA show no methane adsorption and fully reversible methane adsorption respectively, K4.2Ca3.9-LTA and Na11K1-LTA show large hysteresis which reflects the possibility of storage. The hysteresis vanishes when isotherm adsorption temperature increases. Kinetics of desorption were evaluated through manometric and dynamic home-made chromatographic experiments. Results indicate that methane can be strongly trapped in specific zeolites, i.e. very minor desorption occurs at normal P and T. Surprisingly, Rietveld refinement shows that the unit cell of K4.2Ca3.9A is not intermediate with respect to the monocationic zeolites Ca-LTA and K-LTA. Also, we can observe an increase of the cell volume of K4.2Ca3.9A when the temperature increase. We propose a temperature-dependent "gate-opening" mechanism which would be triggered by the mobility of K+ between site I and II. This study demonstrates the significant potential of specifically tailored zeolites for gas storage at ambient pressure and temperature, achieving a storage density of methane that is twenty times greater than its natural density for the same P and T conditions. We assume that the underlying “gate-opening” mechanism is linked to the cation mobility triggered by the temperature.

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Dates et versions

hal-05012176 , version 1 (31-03-2025)

Identifiants

  • HAL Id : hal-05012176 , version 1

Citer

C. Grimaud, C. Daniel, A. Tuel, A. Mesbah, D. Farrusseng. Roles of cation location in LTA zeolite for methane storage. 40th annual congress of the French Zeolite Association, Mar 2025, Blériot-Plage, France. ⟨hal-05012176⟩
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