Adsorption energy and pore-size distributions of activated carbons calculated using Hill's model

Abstract

An integral equation derived using a statistical physics treatment by considering the adsorption energy distribution (AED) was used to model the adsorption of ethylene and ethane on resorcinol-formaldehyde-based activated carbon xerogels. Hill's model was taken as a local adsorption isotherm. This model was based on a grand canonical ensemble. Then a relationship between the energetic and the structural heterogeneities is used to determine the pore-size distribution (PSD) function. The AED and PSD obtained illustrate the greater affinity of activated carbon for adsorption of ethylene compared to ethane. In addition, this method was applied to determine the PSD of the British Drug House (BDH) activated carbon. The behaviour of the obtained PSDs at different temperatures was examined and related to the adsorption capacity of BDH activated carbon towards ethane, methane and nitrogen.