(443a) Investigation of Adsorption Equilibria of Pure Gases (Co,Co2,Ch4) and Their Binary and Ternary Mixtures at T=293 K for Pressures up to 1.1 Mpa on Activated Carbon (Acal)

Adsorption equilibria of the pure gases carbon monoxide (CO), carbon dioxide (CO2) and methane (CH4) and their 3 binary mixtures (CO-CO2, CO2-CH4, CH4-CO) and their ternary mixture (CO, CO2, CH4) on a microporous activated carbon (ACAL) have been investigated experimentally and analytically at 293 K for pressures up to 1,1 MPa. Volumetric-gravimetric measurements have been performed using a magnetic suspension balance (Rubotherm GmbH, Bochum, Germany, 3-site-type), which allows simultaneous adsorption and density measurements of the sorptive gas. From these measurements adsorption equilibria of pure gases and binary gas mixtures can be determined numerically, whereas ternary gas mixture adsorption equilibria require additional measurements of the sorptive gas concentrations in equilibrium by a gas chromatograph or a mass spectrometer [1]. Two thermodynamic models, the two-site Langmuir adsorption isotherm (2LAI) and the Ideal Adsorbed Solution Theory (IAST) have been used to correlate/fit adsorption equilibria data of the pure gases and their mixtures. The parameters determined from pure gas adsorption isotherms have been used to predict coadsorption equilibria data. The relative mean deviation (fm) and the relative dispersion (R) of calculated and measured amounts of gas adsorbed have been calculated. From these (fm, R) data it clearly can be seen that coadsorption equilibria of the above mentioned mixtures can not be predicted or calculated accurately from pure gas adsorption isotherm data by any of the models used. The experimental equipment, procedure of measurement and the data are presented and discussed to a certain extend.

[1] Keller, J. U., Staudt R. Gas Adsorption Equilibria, Experimental Methods and Adsorption Isotherms, p.422, Springer, New York etc., 2005.