A Model for Adsorption Capacities of Charcoal Beds: II. Challenge Concentration Effects

Equilibrium and kinetic capacities of charcoal beds for adsorbed toxic gases and vapors depend on the concentrations of those gases and vapors. Water vapor also affects these capacities. The assumption of competitive (vapor vs. water vapor) equilibria for adsorption led to a mathematical model that quite successfully described relative humidity effects on adsorption capacities of water-immiscible vapors. This same model now has been demonstrated to describe published and new data on vapor concentration effects equally well. Parameters obtained from fits of experimental data with the model can be used for comparisons of charcoal characteristics, adsorbate-charcoal interactions and water-charcoal interactions. Correlations by this model are useful for extrapolating data to untested vapor concentrations and relative humidity conditions.