Adsorption equilibrium isotherms of n-hetpane

n-octane and n-decane on 5A zeolites with intracrystalline mesopores were studied by gravimetric technique at 293

308 and 318 K

and were compared with that on microporous 5A zeolite. The adsorption data from the three n-paraffins on mesoporous 5A zeolites are well correlated by the Langmuir-Freundlich and Toth models. Due to the coexistence of micropores and mesopores on mesoporous 5A zeolites

the maximum adsorption capacity is higher and the energetic heterogeneity is more obvious

while the affinity to the adsorbent evaluated by Henry's constant and the heat of adsorption at zero coverage decrease in the presence of mesopores in zeolite crystals. The isosteric heat of adsorption calculated by Clausius-Clapeyron equation decreases with the increase of surface coverage of n-paraffins. The change of decane is most obviously.