CO2 adsorption in LiY and NaY at high temperature: molecular simulations compared to experiments

Abstract

Grand Canonical Monte Carlo simulations combined with adsorption measurements have been carried out to gain further insight into the CO 2 adsorption process at the microscopic scale in both LiY and NaY faujasites at various temperatures. A new Li + −CO 2 force field derived by ab initio calculations was validated by a reasonable agreement between the simulated isotherms and those obtained by experiments in a wide range of temperature (from 323 K to 473 K). In addition, the microscopic mechanisms of CO 2 adsorption in both systems, consistent with the trends observed for the simulated differential enthalpies of adsorption as a function of the loading, were proposed. It was observed that two different types of adsorption behaviour exist for NaY and LiY at 323 K and 373 K, mainly caused by the significant more exposed position of the SII Na + from the six-ring plane of the supercage compared to those occupied by the SII Li + , whereas at higher temperature, both faujasites exhibit the same flat profile for the differential enthalpy of adsorption as a function of loading.

Optimal Faujasite structures for post combustion CO 2 capture and separation in different swing adsorption processes

“…This represents a step further with respect to other works published in literature, in which the position of the cations is optimized, then frozen before running the GCMC simulation. [10,41,42,43,44,45]…”

Microcalorimetric and FTIR Study of the Adsorption of Carbon Dioxide on Alkali-Metal Exchanged FER Zeolites

“…Several studies of CO 2 adsorption on particular zeolites appeared. Attention has been paid mainly to low-silica zeolites such as faujasites or chabazites due to their high adsorption capacity [3][4][5][6][7][8][9][10][11][12][13][14]. In addition, the study of CO 2 adsorption on ZSM-5 [4,9,[15][16][17], BEA [9,18], FER [19], MCM-22 [20,21] and ITQ-6 [22] was reported in the literature.…”

Variable‐Temperature IR Spectroscopic and Theoretical Studies on CO2 Adsorbed in Zeolite K‐FER

“…Aside from CCS, improved CO 2 adsorbents could find several other practical applications, such as removal of CO 2 from natural gas to improve its energy density [6] and purification of breathing air (e.g., in submarines and spacecraft for long-term space missions). [7] Among prospective porous solids for reversible CO 2 adsorption, metal-organic frameworks (MOFs) and related compounds, [8][9][10][11][12][13][14] porous carbons, [15][16][17][18][19] and zeolites [20][21][22][23][24][25][26][27][28][29][30][31][32] are the main types receiving current attention. For several reasons, zeolites are particularly well suited for fundamental studies aimed at detailed understanding of the gas-solid interactions that dictate adsorption thermodynamics, which is a main factor determining adsorbent performance: 1) zeolites have well-defined (and known) crystal structures, 2) they can easily undergo cation exchange, and 3) zeolites display a wide topological variety.…”