Multisite Langmuir model applied to the interpretation of sorption of n-paraffins in 5A zeolite

Adsorption equilibrium isotherms of n-paraffins from methane to decane on 5 A zeolites (crystals and pellets) were compiled in a wide range of temperat ure and pressure. The data were correlated using the MSL (multisite Langmui r) model for homogeneous surfaces. It is shown that it is possible to corre late all adsorption isotherms by maintaining thermodynamic consistency on m odel parameters. However, for paraffins with more than seven carbons it is necessary to account for the effects of lateral interaction of adsorbed mol ecules. The heat of adsorption for C-1-C-10 paraffins linearly increases wi th the carbon number, ranging from 4.6 kcal/mol for methane up to 23.2 kcal /mol for n-decane.