(419c) The Diffusion of CO2 and N2 in 13X Zeolite Particles of Different Sizes Using a 100 Hz Volumetric Frequency Response System

Frequency response methods have been developed as an alternative technique for the determination of mass transfer mechanisms controlling the transport of gases into and out of microporous adsorbent materials. Recent results in the literature are showing that this technique seems to be the best for discriminating the controlling mechanism. It is also possible to reveal two or more different controlling mechanisms that may dominate in different frequency ranges. This presentation will focus on the operation of a new 100 Hz volumetric frequency response (VFR) system for exploring the diffusion of CO₂ and N₂ in 13X zeolite particles of different sizes.

It is well established that the transport of both N₂ and CO₂ in 13X zeolite is macropore limited. A newly developed volumetric frequency response analyzer that can operate up to 100 hz is utilized to evaluate the role of the adsorbent particle size on the adsorption kinetic of these two species on 13X at temperatures of 30 and 50 ^oC and pressures of 100, 200 and 760 kPa. The experimental results are evaluated against kinetic models to assess the possible transition from a macropore into a micropore limited transfer of these species as the adsorbent particle size decreases. The latest results of this study will be presented.