Experimental measurements and theoretical analysis of the uptake and surface temperature were presented for adsorption of water by synthetic NaX zeolite pellets of different sizes. It was shown that, under the present experimental conditions, the heat dissipation effect plays a dominant role in the adsorption kinetics, after a short initial stage which was controlled essentially by both the macropore diffusion and the micropore diffusion. An excellent agreement was obtained between the experimental data and theoretical results given by a non-isothermal model for a bi-disperse structure, both for the uptake and for the surface temperature curves. The values of diffusivities determined by the curve-fitting method over an initial stage were of the order of 3 x 10−5m2/s for

macropore diffusion. These values exhibited an independence of the pellet size for all the tested pellets. Furthermore, it was demonstrated that the use of an effective model for the monodisperse structure may also give a good agreement, but the values of diffusivities determined by the best fit were not very meaningful because of their dependence on the pellet size.

Nonisothermal Adsorption of Water by Synthetic NaX Zeolite Pellets. K.Abdallah, P.Grenier, L.M.Sun, F.Meunier: Chemical Engineering Science, 1988, 43[10], 2633–43