Effects of CS₂ Solvent Extraction on Nanopores in Coal

This study investigates the effects of the carbon disulfide (CS2) extraction on nanopores of the anthracite samples. Comprehensive pore measurement techniques, including high-pressure mercury intrusion (HPMI), low-temperature nitrogen adsorption (LTNA), and low-temperature CO2 adsorption (LTCA), were employed to analyze the variations of nanopore structure and fractal characteristics. After CS2 extraction, the macropore average diameter and volume increase, while the macropore area and fractal dimension decrease, indicating the pore-enlarged and fractal dimension-reduced effects of CS2 extraction on macropores. The pore-generated and fractal dimension-increased effects of CS2 extraction on mesopores induce reduction in the average diameter and an increase in mesopore volume, area, and fractal dimension. The pore-enlarged and fractal dimension-reduced effects of CS2 extraction on micropores cause an increase in the average diameter and reduction in micropore volume, area, and fractal dimension. These effects of CS2 extraction on nanopore structure are conducive to enhancing CBM transport. This study can provide a theoretical basis on the chemical reservoir stimulation technique with CS2 extraction.