Abstract
An adsorption model combining localized and nonlocalized adsorptions is presented to interpret the adsorption isotherms of water and methanol in zeolitic sorbents of type A. The Langmoir equation is used for the localized adsorption of water and the van der-Waals-type equation is suggested for nonlocalized adsorption. For methanol adsorption the extended form of the Langmuir equation based upon the model in which one molecule occupies two adjacent sites, plays a significant role. Single-component adsorptions of water and methanol on Molecular Sieve 4A are represented fairly well by means of two adjustable parameters, an adsorption equilibrium constant and a physical interaction parameter. The theory can predict the selective adsorption of water from aqueous methanol solutions without any adjustable parameters.
