Effects of types of zeolites on adsorption of organic solvent vapors using the gas chromatographic technique

Abstract

Adsorption equilibrium constants of dilute toluene and o-xylene vapors on 4A, 13X and NaZSM-5 zeolites were measured under chromatographic conditions, at selected temperatures. Chromatographic pulse responses were analyzed by the method of moment in order to determine adsorption equilibrium constant for linear isotherm and adsorption rate constant at the selected temperatures within the range of 80-225℃. Under a selected condition, toluene vapor was able to be adsorbed preferably on 13X, NaZSM-5 and 4A, respectively. While the same amount of o-xylene was adsorbed on those adsorbents. The adsorption of both adsorbates were able to be enhanced by exchanging Na+ with NH4+ and H+. Furthermore, both toluene and o-xylene were adsorbed additionally on binder of 4A and 13X. Both toluene and o-xylene were adsorbed on 4A more fast than other zeolites. The adsorption rate constants for both vapors on each zeolite were almost independence of temperature. The heats of adsorption of both vapors on all studied zeolites were close to the heats of condensation of both toluene and o-xylene.