EFFECT OF SURFACE ENERGETIC HETEROGENEITY ON THE KINETICS OF ADSORPTION OF GASES IN MICROPOROUS ACTIVATED CARBON

A model allowing for surface energetic heterogeneity is presented to d escribe the adsorption and desorption kinetics of gaseous adsorbates i n large microporous particles. The effects of surface energetic hetero geneity on both sorption kinetics and equilibrium (rather than on equi librium only) are studied. Parameters extracted from single component fittings are used to predict the multicomponent sorption dynamics. Sin gle and multicomponent experimental data of sorption dynamics of ethan e and propane in Ajax activated carbon, which are obtained by using a differential adsorption bed, are used to demonstrate the potential of the proposed model. It is found that the role of energetic heterogenei ty is not important in the model fittings of adsorption kinetics of si ngle component, but it plays a vital role in the predictions of desorp tion kinetics of single species and adsorption and desorption processe s of multicomponent gases in microporous particles. This finding has a far reaching consequence as all adsorption systems of industrial inte rest involve interaction of many adsorbates.