ADSORPTION OF TRACE GASES (PROPANE, BUTANE AND FREON-12) FROM CARRIERGASES (HELIUM, NITROGEN AND CARBON-DIOXIDE) ON ACTIVATED CARBON

Adsorption at ppm concentrations of propane, n-butane and dichlorodifl uoromethane (Freon-12) gases and their mixtures from carrier gases hel ium, nitrogen, and carbon dioxide was measured on activated carbon at atmospheric pressure and 290 K. The experimental data are compared wit h predictions for an ideal-adsorbed-solution based upon single-gas (SG ) and single-solute (SS) standard states. The SG standard states under estimate the adsorption of trace components with an average error of 2 5%. Average errors from SS standard states are only 8%, but new experi mental isotherms are required for each trace component if the carrier gas is changed. Adsorbed-phase non-idealities observed for these syste ms can be explained by differences in size between large trace-gas mol ecules and small carrier-gas molecules.