Binary gas adsorption on molecular sieves. Experimental data for the adsorption of oxygen, nitrogen and oxygen-nitrogen mixtures on five molecular sieve adsorbents at various temperatures and pressures and a comparison with theoretical models.

摘要

A study of adsorption equilibria of oxygen, nitrogen andudoxygen-nitrogen mixtures on types 4A, 5A, 13X and Na-Mordenite molecularudsieve pellets has been made.udPure component isotherms, using a volumetric apparatus, haveudbeen measured for each gas on each adsorbent at pressures up to 9 barudand for temperatures of 278.15,293.15 and 303.15 K.udCurve fitting of the pure canponent isotherms has been attemptedudusing the kinetic model of Gonzalez and Holland, the vacancy solutionudmodel, the statistical thermodynamic model and a mathematical equationudsimilar to the Hill-de Boer model. With the exception of the kineticudmodel, good curve fitting was obtained.udBinary equilibria data have been measured, using a constantudvolume method, for mixtures of oxygen and nitrogen at pressures ofud1.7 and 4.4 bar and at temperatures of 278.15,293.15 and 303.15 Kudfor each of the adsorbents. These results have been presented graphicallyudas equilibrium phase compositions and corresponding totaludadsorption loadings.udThe binary experimental equilibria data have been examinedudagainst values predicted by mixture models (kinetic model, the extendedudvacancy solution model, the statistical thermodynamic model, the Cookudand Basmadjian model, and the ideal adsorbed solution theory) usingudregression parameters obtained from the pure component isotherms. Theudstatistical thermodynamic model and the ideal adsorbed solution theoryudgave the best representation of the experimental data.udThe activity coefficients of the adsorbed phase for the binaryudexperimental data have been calculated and the results showed noudappreciable deviation of the adsorbed phase from ideality.