ADSORPTION EQUILIBRIUM-CONSTANTS AND INTRAPARTICLE DIFFUSIVITIES IN MOLECULAR-SIEVES BY TRACER-PULSE CHROMATOGRAPHY

A perturbation chromatography technique using radiotracer gases has been developed to determine the adsorption equilibrium constants and diffusivities in molecular sieves. The ethane and ethylene 13X molecular sieve systems were studied in regions of high concentration. The data obtained by this technique are shown to be in agreement with equilibrium data obtained by static methods and with kinetic data obtained by adsorption uptake and chromatographic methods, but not with kinetic data obtained using NMR techniques. The tracer-pulse chromatographic technique is much more efficient for obtaining gas adsorption equilibria and intraparticle diffusivities and is considerably easier to adapt to wide pressure and temperature ranges than the conventional methods.