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The rigid adsorbent lattice fluid model for pure and mixed gas adsorption
Author(s) -
Brandani Stefano
Publication year - 2019
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.16504
Subject(s) - adsorption , thermodynamics , fugacity , saturation (graph theory) , nanoporous , henry's law , chemistry , materials science , organic chemistry , mathematics , physics , solubility , combinatorics
The ability of macroscopic models to predict correctly multicomponent systems from pure component isotherms alone remains a major challenge in adsorption engineering. A new fundamental thermodynamic model for multicomponent adsorption of molecules of different size in nanoporous materials is derived from a modified lattice fluid model. Expressions for the fugacity coefficients are derived and the resulting equilibrium relationships are shown to be consistent with a type I adsorption isotherm. Expressions are obtained for the saturation capacity, the Henry law constant and the adsorption energy. The model is applied to silicalite and the parameters for the adsorbent are obtained from crystal properties, the adsorption energy of n ‐alkanes and Henry law constants for six gases. Model predictions for gas adsorption up to 20 bar are shown to be comparable to empirical adsorption isotherm equations. Extension to binary and quaternary systems shows good a priori predictive capability when compared to experimental data. © 2018 American Institute of Chemical Engineers AIChE J, 65: 1304–1314, 2019