Effect of internal moisture on CH4 adsorption and diffusion of coal: A molecular simulation study

Abstract To reveal the influence of internal moisture on CH4 adsorption and diffusion is of great significance to the development of coalbed CH4. Here, we use molecular simulation methods to explore the influence of internal moisture on the microporous morphology, adsorption property, and diffusion behavior. The results show that internal moisture can change the structural properties of coal, and the pore structure parameters reduce with increase of the internal moisture. Adsorption property indicators indicate an increased internal moisture can reduce the adsorption property. In addition, a negative correlation between the internal moisture and self- and transport diffusivities coefficient is revealed.