Characterization of Activated Carbons using Liquid Phase Adsorption

A modification of the adsorption integral based on the Dubinin-Radushkevich model is proposed here to account for finite adsorbate molecular size and steric hindrance of the pore walls. The model is successfully applied to both gas and liquid phase adsorption, yielding more consistent and improved data interpretation in both cases. In particular for gas phase adsorption the model yields considerably improved predictions at high pressures, based on our application to the adsorption of various gases on Nuxit activated carbon. For the liquid phase our experimental data on the adsorption of flavour esters on Filtrasorb 400, Norit ROW 0.8 and ROX 0.8 is also found to be better represent by the proposed model, yielding more consistent and realistic parameters values. The ester molecular diameters, being largely unknown were also extracted from fits of the adsorption data, and were found to be consistent with estimates based on critical volumes