Monte Carlo simulation of adsorption of gases in carbonaceous slitlike pores.

Abstract

To obtain the theoretical maximum adsorption isotherms of methane in a slitlike pore of graphite carbon, the single-plane wall model, which allows molecules to be adsorbed on both sides of the graphite basal plane, is considered. The LJ potential function is used for describing interactions between both molecule-molecule and molecule-surface carbon. The equilibrium densities in a pore and in a gas phase are calculated by using the Gibbs ensemble Monte Carlo simulation technique. When the slitwidth is designed such that methane molecules are accommodated in two layers, the theoretical adsorptions in the single-plane wall pore almost quantitatively coincide with the experimental isotherms of methane and ethane on high-surface area carbon M-30 at 298 K, which suggests that carbon M-30 adsorbs methane to almost the theoretical maximum quantity. Comparisons are made with a different slitwidth pore and the double-plane wall model which assumes that only one side of the graphite plane is effective for adsorption.