High pressure methane adsorption of medium and high-rank coal in southern Qinshui basin

Methane adsorption is a physical process occurring in the inner-surface of coal pores. The pore network in coals provides plenty of accommodation for medium and high-pressure methane adsorption. In this study, we conducted high-pressure methane adsorption on southern Qinshui medium and high rank coals. We further discuss the relationship between adsorption parameters obtained from modified D-R model and coal properties and porosity characters. The results indicate that the effect of coal properties on the maximum adsorption capacity and heat of adsorption is a multi-factor-related superimposition. There is a discernible positive correlation between the maximum adsorption capacity with micropore volume and the revised parameter of adsorption amount with specific surface area of macro-mesopore. Methane molecule may display different adsorption behavior according to the pore width on the coal inner surface. On the basis of above observations, a primary understanding of high-pressure methane adsorption in relation to different pore width was proposed, which may provide a new insight of methane adsorption mechanism.