Investigation on the Structure and Fractal Characteristics of Nanopores in High-Rank Coal: Implications for the Methane Adsorption Capacity.

The structure and fractal characteristics of nanopores of high-rank coal were investigated using an approach that integrates N₂ adsorption and field emission scanning electron microscopy (FE-SEM). The results indicated that the high-rank coal of the Shanxi Formation has a complex pore-fracture network composed of organic matter pores, mineral-related pores, and microfractures. The pore type of high-rank coal tends to be complicated, and the main pore types are inkbottle pores and open pores, which are more conducive to methane enrichment.