Molecular Dynamics Simulation of Methane Adsorption and Diffusion: A Case Study of Low-Rank Coal in Fukang Area, Southern Junggar Basin

Adsorption and diffusion are the key factors affecting coalbed methane (CBM) accumulation, resource assessment production prediction. To study adsorption mechanism of Fukang low-rank coal at microscopic level, samples were collected, elemental composition, carbon type distribution functional group structure determined by analysis (Ea), Fourier-transform interferometric radiometer (FTIR), X-ray photoelectron spectroscopy (XPS) 13C nuclear magnetic resonance (13C NMR) experiments to construct a 2D molecular 3D macromolecular model. The characteristics researched giant regular Monte Carlo (GCMC) dynamics (MD) simulation methods. results showed that excess amount increased then decreased with increase in pressure. two stages increasing pressure: sharp decrease coefficient from 0.5 5.0 MPa slow 15.0 MPa. lower pressure, larger effective radius CH4 C atoms, higher temperature, more pronounced radius.