Binary adsorption equilibrium of organics and water on activated carbon

Adsorption isotherms of hexafluoropropylene (HFP), methanol and ethanol wer e measured tinder dry and humid conditions using Norit RI carbon. The Prese nce of water lowered the HFP capacity over the whole pressure range as comp ared to the single component isotherm, while increasing the methanol and et hanol capacity. The Dubinin-Radushkevich equation was applicable for methan ol, and ethanol, and the Dubinin-Astakhov equation gave a satisfactory desc ription for water. The ideal adsorbed solution (IAS) theory satisfactorily described the binary, miscible systems of methanol and ethanol with water. Because water and HFP are not miscible, the IAS theory cannot be used. This binary system was described well by the independent co-adsorption of the t wo components, that is, HFP vapor is adsorbed in the micropore volume left free by water.