Microstructure and its influence on CH₄ adsorption behavior of deep coal

In this paper we investigate the influence of microstructure on the CH₄ adsorption behavior of deep coal. The coal microstructure is characterized by N₂ adsorption at 77 K, scanning electron microscopy (SEM), Raman spectroscopy, and Fourier transform infrared spectroscopy (FT-IR). The CH₄ adsorptions are measured at 298 K at pressures up to 5.0 MPa by the the volumetric method and fitted by the Langmuir model. The results show that the Langmuir model fits well with the experimental data, and there is a positive correlation with surface area, pore volume, I_D/I_G, and CH₄ adsorption capacity. The burial depth also affects the methane adsorption capacity of the samples.