Modeling of adsorption on porous activated carbons using SLD-ESD model with a pore size distribution

The simplified local density (SLD) approach using the Elliott, Suresh, Donohue (ESD) equation of state is developed to model the adsorption on porous activated carbons by consideration of the pore size distribution (PSD). The SLD-ESD approach is used to calculate the local adsorption amount for a given pore width. The total adsorption on porous materials is the sum of all local adsorption amounts over entire range of pore structure sizes. The adsorption of a pure component can be fitted well by this SLD-ESD model for a wide temperature range. The reasonability and reliability of PSDs obtained from different gas probes are characterized. The PSDs determined by the adsorption data of pure components have been used to predict the adsorption equilibria of binary mixtures. By applying to different systems for wide conditions, the predictive capacity of this model was examined. It is shown that the SLD-ESD theoretical model in conjunction with PSD analysis can provide a reasonable prediction for mixture adsorption.

► We firstly improved the simplified local density theory by consideration of pore distributions.
► Porous structures of adsorbents can be characterized through this model.
► This model can reasonably correlate and predict the mixture adsorption equilibria.