Open AccessPore Fractal Characteristics of Suancigou Long-Flame Coal after Electrochemical Treatment: An Experimental Study through the Implementation of N2 Adsorption and Mercury Intrusion Prosimetry Techniques
Author(s) -
Xiaoyu Zhang,
Jian Cheng,
Liankun Zhang,
Tianbai Zhou,
Tianhe Kang,
Ligong Li
Publication year - 2021
Publication title -
acs omega
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.779
H-Index - 40
ISSN - 2470-1343
DOI - 10.1021/acsomega.1c04231
Subject(s) - materials science , electrochemistry , adsorption , coal , mesoporous material , chemical engineering , dissolution , macropore , fractal , mineralogy , electrode , chemistry , organic chemistry , mathematical analysis , mathematics , engineering , catalysis
The application of electrochemical treatment in coal seams for enhancing coalbed methane (CBM) recovery can also decrease the risks of outburst disasters. The long-flame coal samples were electrochemically modified with 0, 1, 2, and 4 V/cm electric potential gradients, and the pore structures were measured and analyzed by combined low-temperature nitrogen gas adsorption, mercury intrusion prosimetry, and fractal theory. The experimental test results indicated that the pore volumes of macropores (>50 nm) and mesopores (2-50 nm) increased after electrochemical modification and further increased with the increase in electric potential gradient. The fractal dimensions of pores showed a decreasing trend except for the slight fluctuation of the mesopores with a size of 2-4.5 nm after modification, which indicated that the overall roughness and irregularity index of pores decreased. The evolution mechanisms of pore size distributions and their fractal dimensions were explained by the dissolution of minerals and the falling off of alkane side chains in the coal surface, which would expand and connect the pores during the electrochemical modification process. The results obtained from this work were crucial for CBM exploration via an electrochemical method.