The Adsorption and Desorption Behavior of CH₄ on Jincheng Anthracite Modified in Fe³⁺ and Cu²⁺ Ion Electrolytes

Abstract

The anthracite was electrochemically treated in Fe 2 (SO 4 ) 3 and CuSO 4 electrolytes, and the adsorption capacity and desorption ratio of CH 4 on the anthracite were investigated using adsorption and desorption tests. The experimental results demonstrated that the saturated adsorption capacity of CH 4 on anthracite decreased from 41.49 to 38.31 mL g −1 after being modified by the Fe 3+ ion electrolyte and further decreased to 34.84 mL g −1 after being modified by the Cu 2+ ion electrolyte. The CH 4 desorption ratio increased from 63.43 to 73.66% and 84.87% after modification in Fe 3+ and Cu 2+ ion electrolytes, respectively, and this improvement was caused by the enlargement of the diffusion coefficient D. The effect of the Cu 2+ electrolyte on CH 4 adsorption/desorption was better than that of the Fe 3+ electrolyte, and the mechanism was analyzed by the changes in the surface energy, functional groups, and pore characteristics before and after modification. The results obtained from this work provide a basis for the optimization of ion electrolytes when accelerating methane extraction via an electrochemical method.

Effect of Cyclical Microwave Modification on the Apparent Permeability of Anthracite: A Case Study of Methane Extraction in Sihe Mine, China

“… 70 The peak at 1430 cm –1 is identified as the bending vibration of −CH 3 and the antisymmetric stretching vibration of carbonate groups. 32 The peak near 1030 cm –1 is attributed to the stretching vibrations of Si–O–Si and Si–O–C. 33 The peak near 540 cm –1 corresponds to the vibrations of S–S.…”

Electrochemical Modification on CH4 and H2O Wettability of Qinshui Anthracite Coal: A Combined Experimental and Molecular Dynamics Simulation Study

“…Figure 2b shows the molecular dynamics simulation results; the CH 4 adsorption was also decreased after electrochemical modification (Table 1). diffusion coefficient was also obtained according to eq 2, 17 the results are shown in Figures 4 and 5. i k j j j j j y…”

Pore Fractal Characteristics of Suancigou Long-Flame Coal after Electrochemical Treatment: An Experimental Study through the Implementation of N2 Adsorption and Mercury Intrusion Prosimetry Techniques

“…The fractures of about 91.2 μm of anthracite samples increased after electrochemical modification due to the removal of minerals that filled the fractures; as a result, the gas diffusion distance and desorption time were shortened . The advantages of electrochemical modification fused the controllability of the directions of coal particles and water, uniform distribution of electroosmotic flow, and insensitivity to the pore size. , …”

“…10 The advantages of electrochemical modification fused the controllability of the directions of coal particles and water, uniform distribution of electroosmotic flow, and insensitivity to the pore size. 12,13 The fractal theory combined with LP-N 2 GA tests, NMR tests, mercury intrusion prosimetry (MIP) tests, focused-ion beam-scanning electron microscopy (FIB-SEM), and X-ray computed micro-tomography (X-ray μ-CT) is a good method for characterizing the pore structures of coal and other porous media. 14−18 Su et al discussed the effect of modification on the fractal dimensions of pore structures of long-flame coal, and the results showed a continuously decreasing tendency after cyclical supercritical CO 2 treatment.…”