An adsorption isotherm equation for nonideal pure component adsorption based on vacancy solution theory and the Non-Random-Two-Liquid (NRTL) equation is found to be useful for predicting pure component adsorption equilibria at a variety of conditions. The isotherm equation is evaluated successfully by means of pure component experimental data for different adsorbates (methane, ethane, propane, n-butane, ethylene, propylene, carbon dioxide) and different adsorbents (Nuxit-AL active carbon, 13X molecular sieves, BPL carbon and carbon molecular sieve 5A). In order to fully describe the pure component adsorption systems, spreading pressure and isosteric heat of adsorption are also calculated.
Adsorption Science and Technology, Do, D.d. (ed.), 2000