Physical and chemical aspects of the study of clusters, nanostructures and nanomaterials
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General phenomenological approach for the description of adsorption and absorption equilibria

A.V. Tvardovskiy

Tver State Technical University

DOI: 10.26456/pcascnn/2022.14.XXX

Original article

Abstract: Up to the present time, the construction of a general theory of the equilibrium adsorption is a very urgent task. In the present paper, a general phenomenological approach is developed to describe both adsorption and absorption equilibria. It was shown that under certain assumptions, the resulting equation transforms into the well-known classical Henry, Langmuir, Brunauer-Emmett-Teller equations with constants having a clear physical meaning. Thus, the constant in the Henry equation is determined by the temperature, the specific surface of the adsorbent, the size of the adsorbate molecules, the molar mass of the adsorbate and the isosteric heat of adsorption (the energy of interaction of the adsorbate molecules with the surface of the adsorbent). In the derived Brunauer-Emmett-Teller partial equation, in contrast to the classical version, a clear dependence of the equation constant on the specific physical characteristics of the adsorption system is indicated for the first time. It is determined by the concentration of adsorbate molecules in the liquid phase at the temperature under consideration, the concentration of adsorbate molecules during the formation of a dense monolayer on the surface of the adsorbent, the energy of interaction of adsorbate molecules with the surface of the adsorbent and the heat of condensation. The presented approach can serve as a basis for modeling a variety of adsorption and absorption phenomena, including adsorption on microporous adsorbents.

Keywords: adsorption, adsorbent, absorption, thermodynamics of phase equilibria, Henry equation, Langmuir equation, Brunauer–Emmett–Teller equation

  • Andrey V. Tvardovskiy – Dr. Sc., Professor, Rector, Tver State Technical University

Reference:

Tvardovskiy, A.V. General phenomenological approach for the description of adsorption and absorption equilibria / A.V. Tvardovskiy // Physical and chemical aspects of the study of clusters, nanostructures and nanomaterials. – Tver: TSU, 2022. — I. 14. — P. ___-___. DOI: 10.26456/pcascnn/2022.14.XXX. (In Russian).

Full article (in Russian): download PDF file

References:

1. Bulnes F.M., Ramirez‑Pasto A.J. Adsorption of interacting binary mixtures on heterogeneous surfaces: theory, Monte Carlo simulations and experimental results, Adsorption, 2019, vol. 25, issue 7, pp. 1317-1328. DOI: 10.1007/s10450-019-00093-7.
2. Pérez‑Chávez N.A., Albesa A.G., Longo G.S. Molecular theory of glyphosate adsorption to pH‑responsive polymer layers, Adsorption, 2019, vol. 25, issue 7, pp. 1307-1316. DOI: 10.1007/s10450-019-00091-9.
3. Abbasi A., Abdelrasoul A., Sardroodi J.J. Adsorption of CO and NO molecules on Al,P and Si embedded MoS2 nanosheets investigated by DFT calculations, Adsorption, 2019, vol. 25. issue 5, pp. 1001-1017. DOI: 10.1007/s10450-019-00121-6.
4. Sladekova K., Campbell C., Grant C. et al. The effect of atomic point charges on adsorption isotherms of CO2 and water in metal organic frameworks, Adsorption, 2021, vol. 27, issue 6, pp. 995-1000. DOI: 10.1007/s10450-021-00301-3.
5. Sastre G.J., Kärger J., Ruthven D.M. Surface barriers and symmetry of adsorption and desorption processes, Adsorption, 2021, vol. 27, issue 5 (Topical Issue: Diffusion in Nanoporous Solids, vol. 2), pp. 777-785. DOI: 10.1007/s10450-020-00260-1.
6. Van Assche T.R.C., Baron G.V., Denaye J.F.M. An explicit multicomponent adsorption isotherm model: accounting for the size-effect for components with Langmuir adsorption behavior, Adsorption, 2018, vol. 24, issue 6, pp. 517-530. DOI: 10.1007/s10450-018-9962-1.
7. Dastani N., Arab A., Raiss H. Adsorption of Ampyra anticancer drug on the graphene and functionalized graphene as template materials with high efficient carrier, Adsorption, 2020, vol. 26, issue 6, pp. 879-893. DOI: 10.1007/s10450-019-00142-1.
8. Avijegon G., Xiao G., Li G., May E.F. Binary and ternary adsorption equilibria for CO2 / CH4 / N2 mixtures on Zeolite 13X beads from 273 to 333 K and pressures to 900 kPa, Adsorption, 2018, vol. 24, issue 4, pp. 381-392. DOI: 10.1007/s10450-018-9952-3.
9. Ghasemi A.S., Mashhadban F., Ravari F. A DFT study of penicillamine adsorption over pure and Al-doped C60 fullerene, Adsorption, 2018, vol. 24, issue 5, pp. 471-480. DOI: 10.1007/s10450-018-9960-3.
10. Berezovsky V., Öberg S. Computational study of the CO adsorption and diffusion in zeolites: validating the Reed–Ehrlich model, Adsorption, 2018, vol. 24, issue 4, pp. 403-413. DOI: 10.1007/s10450-018-9948-z.
11. Brunauer S., Emmett P.H., Teller E. Adsorption of gases in multimolecular layers, Journal of the American Chemical Society, 1938, vol. 60, issue 2, pp. 309-319. DOI: 10.1021/ja01269a023.
12. Langmuir I. The adsorption of gases on plane surfaces of glass, mica and platinum, Journal of the American Chemical Society, 1918, vol. 40, issue 9, pp. 1361-1403. DOI: 10.1021/ja02242a004.
13. Henry D.C. LX. A kinetic theory of adsorption, The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science. Series 6, 1922, vol. 44, issue 262, pp. 689-705. DOI: 10.1080/14786441108634035.

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