Role of hydrogen bonding in the capture and storage of ammonia in zeolites

I. Matito-Martos , A. Martin-Calvo , Conchi Maria Concepcion Ovin Ania (1) , J.B. Parra , J.M. Vicent-Luna , S. Calero (2)

1 CEMHTI - Conditions Extrêmes et Matériaux : Haute Température et Irradiation
2 UGM - Unité de recherche Génétique Microbienne

Ammonia is an important chemical compound used in a wide range of applications. This makes its capture, purification and recovery necessary. In this work we combine experimental and molecular simulation techniques to investigate the adsorption of ammonia using zeolites. Adsorption isotherms were measured in several commercial pure silica zeolites (including MFI, FAU, and LTA topologies), showing their potential to be used in large scale processes with lower cost than current techniques. In addition, we performed molecular simulations to describe the adsorption mechanisms from a microscopic point of view. We carried out Monte Carlo simulations to calculate the adsorption isotherms and to this aim we first developed a transferable set of potential parameters to describe the interactions of ammonia with the zeolites. We analyzed the adsorption energy between the adsorbents and the fluid involved in the adsorption process and the effect of confinement on the microscopic structure of ammonia. This was compared with the liquid phase via radial distribution functions and hydrogen bond analyses. Here we describe the mechanisms that govern the adsorption of ammonia in zeolites as well as the effect exerted on the adsorption by the structural flexibility and by the presence of minimal amount of extra-framework species.

Domaines: Ingénierie de l'environnement; Matériaux; Catalyse

I. Matito-Martos, A. Martin-Calvo, Conchi Maria Concepcion Ovin Ania, J.B. Parra, J.M. Vicent-Luna, et al.. Role of hydrogen bonding in the capture and storage of ammonia in zeolites. Chemical Engineering Journal, 2020, 387, pp.124062. ⟨10.1016/j.cej.2020.124062⟩. ⟨hal-02746273⟩