Investigating Segregation Effects in Mixture Adsorption in Mordenite Zeolite Using Monte-Carlo Simulations
Abstract
Configurational-Bias Monte Carlo (CBMC) simulations have been used to investigate segregation effects for adsorption of CO2(1)/CH4(2) and CO2(1)/C3H8(2) mixtures in Mordenite (MOR) zeolite. The segregation effects originate from the preferential location of CO2 in the 8-ring side pockets, and C3H8 in the 12-ring 1D channels; the CH4 molecules locate at both these sites. The segregated nature of mixture adsorption causes the quantitative failure of the Ideal Adsorbed Solution Theory (IAST) that mandates a uniform distribution of guest adsorbates in the zeolite framework. For CO2(1)/C3H8(2) mixtures, thermodynamic non-idealities cause selectivity reversals and azeotropic adsorption. Quantitative match with CBMC data is achieved by introduction of activity coefficients and use of the Real Adsorbed Solution Theory (RAST). The experimental data of Talu and Zwiebel (A.I.Ch.E.J. 32, 1263-1276, 1986) for CO2/C3H8 mixture adsorption in H-MOR are in remarkable agreement with the corresponding CBMC simulation data. The phenomenon of azeotropic adsorption occurs at the same composition in both data sets. The PN-DPL model of Ritter (Langmuir 27, 4700-4712, 2011) is able to anticipate the selectivity reversal phenomena. However, the PN-DPL model fails to match CBMC and experimental data at increased pore occupancies because entropy effects that favor CO2 are not properly catered for by the Ritter model.
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BibTeX
@misc{krishna2026investigating,
title = {{Investigating Segregation Effects in Mixture Adsorption in Mordenite Zeolite Using Monte-Carlo Simulations}},
author = {Rajamani Krishna and Jasper M. van Baten},
howpublished = {ChemRxiv},
year = {2026},
month = sep,
doi = {10.26434/chemrxiv.15008611/v1},
url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008611/v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - Investigating Segregation Effects in Mixture Adsorption in Mordenite Zeolite Using Monte-Carlo Simulations
AU - Rajamani Krishna
AU - Jasper M. van Baten
PY - 2026
DA - 2026/09/09
PB - ChemRxiv
DO - 10.26434/chemrxiv.15008611/v1
UR - https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008611/v1
AB - Configurational-Bias Monte Carlo (CBMC) simulations have been used to investigate segregation effects for adsorption of CO2(1)/CH4(2) and CO2(1)/C3H8(2) mixtures in Mordenite (MOR) zeolite. The segregation effects originate from the preferential location of CO2 in the 8-ring side pockets, and C3H8 in the 12-ring 1D channels; the CH4 molecules locate at both these sites. The segregated nature of mixture adsorption causes the quantitative failure of the Ideal Adsorbed Solution Theory (IAST) that mandates a uniform distribution of guest adsorbates in the zeolite framework. For CO2(1)/C3H8(2) mixtures, thermodynamic non-idealities cause selectivity reversals and azeotropic adsorption. Quantitative match with CBMC data is achieved by introduction of activity coefficients and use of the Real Adsorbed Solution Theory (RAST). The experimental data of Talu and Zwiebel (A.I.Ch.E.J. 32, 1263-1276, 1986) for CO2/C3H8 mixture adsorption in H-MOR are in remarkable agreement with the corresponding CBMC simulation data. The phenomenon of azeotropic adsorption occurs at the same composition in both data sets. The PN-DPL model of Ritter (Langmuir 27, 4700-4712, 2011) is able to anticipate the selectivity reversal phenomena. However, the PN-DPL model fails to match CBMC and experimental data at increased pore occupancies because entropy effects that favor CO2 are not properly catered for by the Ritter model.
ER -