Effect of small-molecule organic matter on methane adsorption in anthracite

Abstract

This study employs the grand canonical ensemble Monte Carlo (GCMC) method to investigate the effect of small-molecule organic matter on methane adsorption in anthracite. Specifically, the adsorption characteristics of methane in anthracite are analyzed considering the type and concentration of single-component and multi-component small-molecular organic matter, alongside parameters such as adsorption heat, adsorption potential energy, interaction energy, and charge transfer amount. Results indicate that methane adsorption exhibits physical adsorption behavior, with adsorption heat decreasing with increasing temperature and adsorption potential energy inversely correlated with adsorption capacity. The influence of different types and concentrations of small-molecular organic matter on methane adsorption varies. The presence of small-molecular organic matter alters the charge transfer amount of methane, with a greater absolute value corresponding to enhanced anthracite adsorption capacity. The interaction hierarchy among single-component small-molecule organic compounds and methane is as follows: methyl benzene > tetrahydrofuran > n-hexane. Additionally, in the presence of multi-component small-molecule organic matter, the simultaneous occurrence of methyl benzene and n-hexane or tetrahydrofuran inhibits adsorption due to chemical reactions.