Adsorption of molecular gases on porous materials in the SAFT-VR approximation

TL;DR

This paper develops a molecular thermodynamic model using SAFT-VR potentials to predict gas adsorption on porous materials, extending it with a quasi-two-dimensional approximation, and validates it against experimental data for various gases.

Contribution

The study introduces an extended SAFT-VR based model with a quasi-two-dimensional approximation for adsorption, providing a new approach to predict gas adsorption on porous media.

Findings

Model predictions agree fairly with experimental data.

Applicable to gases like ethane, ethylene, propane, and CO2.

Effective for porous materials such as activated carbon and silica gel.

Abstract

A simple molecular thermodynamic approach is applied to the study of the adsorption of gases of chain molecules on solid surfaces. We use a model based on the Statistical Associating Fluid Theory for Variable Range (SAFT-VR) potentials [A. Gil-Villegas, A. Galindo, P. J. Whitehead, S. J. Mills, G. Jackson, A. N. Burgess, J. Chem. Phys. 106 (1997) 4168] that we extend by including a quasi-two-dimensional approximation to describe the adsorption properties of this type of real gases [A. Martinez, M. Castro, C. McCabe, A. Gil-Villegas, J. Chem. Phys. 126 (2007) 074707]. The model is applied to ethane, ethylene, propane, and carbon dioxide adsorbed on activated carbon and silica gel, which are porous media of significant industrial interest. We show that the adsorption isotherms obtained by means of the present SAFT-VR modeling are in fair agreement with the experimental results provided in the literature