Physical adsorption of gas mixtures of 2,2-dimethylpropane and n-butane on Vycor glass and on Spherisorb silica

Abstract

A combined volumetric/gravimetric method for accurate measurement of the physical adsorption of gas mixtures at constant total equilibrium pressure is described. The correction for non-ideal gas behaviour is shown to be a major factor and failure to allow for this can lead to incorrect results. Results for mixtures of 2,2-dimethylpropane and n-butane adsorbed at sub-monolayer coverage on Vycor glass and on Spherisorb silica show that 2,2-dimethylpropane is preferred to n-butane over the whole range of compositions, and that the adsorption of each component of the mixture is depressed by the presence of the second component.