Estimation of adsorption of ethane on the superactive microporous carbon adsorbent using the theory of volume filling of micropores

Abstract

Using the main statements of the Dubinin theory of volume filling of micropores (TVFM) the amount of adsorbed ethane was estimated at pressures up to 4 MPa in the temperature range lower and higher than the critical temperature (303–333 K) on the superactive microporous carbon adsorbent with the bimodal micropore size distribution and a total micropore volume of 1.44 cm3 g−1. Two approaches were applied for comparison of the accuracy of calculations: the approach based on the calculation of “standard states” of adsorption and pressure and the approach taking into account the property of linearity of adsorption isosteres of gases in broad ranges of thermodynamic parameters. Both thermodynamic approaches showed good agreement of the results with experimental data and can be recommended for precalculations of adsorption equilibria of gases and vapors on the basis of the minimum physicochemical information about the adsorbent and adsorptive. The high agreement of the experimental and calculated data provides the basis for using the adsorption characteristics obtained in the framework of the TVFM for the calculation of differential molar isosteric heats of adsorption.