Kinetics of adsorption in bi-porous molecular sieves. Part II: Comparison of theory and experiment for batch systems

Experimental kinetic uptake curves for two sorbates (cis-2-butene from the gas phase and n-heptane from the liquid phase) have been measured in a variety of 5A molecular sieve pellets. Conditions were selected to fulfil either the linear isotherm approximation of the Ruckenstein(3) model or the rectangular isotherm approximation of the preceding paper. For these systems both macropore and micropore diffusional resistances are significant and it is shown that the theoretical models provide a satisfactory interpretation of the experimental uptake curves. Time constants for both macropore and micropore diffusion, calculated by matching experimental and theoretical uptake curves, are consistent with independently measured values. On a mesure, pour differentes particules de tamis moleculaire 5A, les courbes de vitesse d'absorption experimentale de deux sorbats, a savoir le cis-2-butene en phase gazeuse et l'heptane normal en phase liquide. On a choisi des conditions qui pouvaient repondre soit a l'approximation de l'isotherme lineaire du modele de Ruckenstein(3), soit a celle de l'isotherme rectangulaire un travail precedent. Pour ces systemes, les resistances a la diffusion dans les macropores et les micropores sont importantes et Ton montre que les modeles theoriques fournissent une interpretation satisfaisante des courbes d'absorption experimentale. Les constantes de temps relatives a la diffusion dans les macropores, calculees en faisant coincider les courbes d'adsorption experimentale et theorique, s'accordent avec les valeurs mesurees independamment.