The effects of microcrystal structures

such as the extension of basic structural unit (La) and the number of basic structural unit (N)

as well as the surface structures including different types of defects and oxygen-containing functional groups

on the adsorption and diffusion of coalbed methane were investigated. The adsorption amounts were simulated by using the Monte Carlo (MC) method

and the diffusion coefficients of coalbed methane were simulated by using molecular dynamics (MD) simulation. All of the simulations were conducted in the condition of 303 K and 10 MPa. It can be concluded that the adsorption capacity of methane on unit mass of coal decreases with N increasing

as well as the existence of defects and oxygen-containing functional groups. The diffusion coefficient of methane increased with La extending and shows a complex process influenced by increasing N. The existence of single-defect and C O was favorable of diffusion of coalbed methane. The coalbed methane was easy to diffuse in larger pore of coal. Finally

the micro model of coalbed methane diffusion for the coal particles of radial heterogeneous was proposed base on the micro-influenced factors and macro performance of the migration of coalbed methane.