Simulation study of sorption of CO[sub(2)] and N[sub(2)] with application to the characterization of carbon adsorbents

Improved approaches to the micropore structure characterization problem have been recently developed based on molecular level theories and statistical mechanics based simulations. In particular, density functional theory (DFT) in a sufficiently elaborate form has been used to provide an accurate description of simple fluids in geometrically simple confined spaces and develop practical methods for the evaluation of the pore structure over a wide range of pore sizes [7-12]. To capture more accurately the behavior of the adsorbates in micropores, it is often necessary to model them as non-spherical molecules with electrostatic interactions. Given the limited capabilities of DFT in this context, molecular simulation based on the Grand Canonical Monte Carlo technique has been established lately as an efficient alternative approach for the generation of adsorption isotherms in carbons and the subsequent determination of PSDs [13-21]. Some authors have combined these studies with structural investigations for the densification process in carbon nanopores using spherical molecules, ethane and carbon dioxide and accounting for effects of pore shape and size, temperature, quadrupole interactions and molecule length [19,22-24].