Abstract
Experimental and simulated data for adsorption of gas mixtures on energetically heterogeneous surfaces like activated carbon and zeolites exhibit negative deviations from ideality. The deviations are large in some cases, with activity coefficients at infinite dilution equal to 0.1 or less. Similar molecules form ideal mixtures, but molecules of different size or polarity are nonideal. Equations for bulk liquid mixtures (Wilson, Margules, etc.) do not apply to isobars for adsorbed mixtures. A two-constant equation for activity coefficients as a function of composition and spreading pressure is in good agreement with theory, simulation, and experiment.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Dunne, J. and A.L. Myers, “Adsorption of gas mixtures in micropores: effect of difference in size of adsorbate molecules,”Chem. Eng. Sci., in press (1994).
Hill, T.L. and S. Greenschlag, “Statistical mechanics of monatomic systems in an external periodic potential field: I. Introduction, virial expansion, and classical second virial coefficient,”J. Chem. Phys.,34, 1538 (1961).
Hoory, S.E. and J.M. Prausnitz, “Monolayer adsorption of gas mixtures on homogeneous and heterogeneous solids,”Chem. Eng. Sci.,22, 1025 (1967).
Karavias, F. and A.L. Myers, “Monte Carlo simulation of binary gas adsorption in zeolite cavities,”Molecular Simulation,8, 51–72 (1991).
Morrison, I.D. and S. Ross, “The second and third virial coefficients of a two-dimensional gas,”Surf. Sci.,39, 21 (1973).
Myers, A.L. and J.M. Prausnitz, “Thermodynamics of mixed-gas adsorption.”AIChE J.,11, 121 (1965).
Oh, B.K. and S.K. Kim, “Viral expansion of the second layer in physical adsorption, anab initio calculation for helium on argon crystal,”J. Chem. Phys.,61, 1797 (1974).
Prausnitz, J.M., R.N. Lichtenthaler, and E.G. Azevedo,Molecular Thermodynamics of Fluid-Phase Equilibria, Prentice-Hall, Engelwood Cliffs, N.J. 1986.
Smith, J.M. and H.C. Van Ness,Introduction to Chemical Engineering Thermodynamics, Third Ed., McGraw-Hill, N.Y., p. 331, 1975.
Steele, W.A.,The Interaction of Gases with Solid Surfaces, Pergamon Press, Glasgow, 1974.
Talu, O. and A.L. Myers, “Rigorous thermodynamic treatment of gas adsorption,”AIChE J.,34, 1887 (1988).
Talu, O. and I. Zwiebel, “Multicomponent adsorption equilibria of nonideal mixtures,”AIChE J.,32, 1263 (1986).
Valenzuela, D.P. and A.L. Myers,Adsorption Equilibrium Data Handbook, Prentice-Hall, Engelwood Cliffs, N.J., p. 216, 1989.
Valenzuela, D.P., A.L. Myers, O. Talu, and I. Zwiebel, “Adsorption of gas mixtures: effect of energetic heterogeneity,”AIChE J.,34, 397 (1988).
Van Ness, H.C., “Adsorption of gases on solids,”I. & E.C. Fundamentals,8, 464, 1969.
Van Ness, H.C. and M.M. Abbott,Classical Thermodynamics of Non-electrolyte Solutions, McGraw-Hill, N.Y., p. 289, 1982.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Talu, O., Li, J. & Myers, A.L. Activity coefficients of adsorbed mixtures. Adsorption 1, 103–112 (1995). https://doi.org/10.1007/BF00704999
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00704999