Work

Changes in Pore Structure and Gas Adsorption–Desorption Characteristics of Coal Under High-Voltage Electric Pulses

Year: 2025

Type: article

Abstract: High-voltage electrical pulses (HVEPs), a new technology designed to enhance the permeability of coal seams, have received significant attention for their application in gas extraction from low-permeability coal seams. This study designed a high-pressure adjustable electrical pulse experimental system to investigate the effects of HVEPs on the pore structure and gas adsorption–desorption characteristics of bituminous coal samples. The results revealed that HVEPs effectively restructured pore morphology in coal samples through the opening of previously sealed and partially enclosed pores. This led to a significant increase in the average pore diameter, total pore volume, and porosity. However, the increase in total specific surface area was minimal. Moreover, the connectivity of pores was continuously enhanced. As the discharge voltage increased, the pore structure significantly improved. However, HVEP treatment slightly increased the adsorption pores (micropores and transition pores) and significantly increased the seepage pores (mesopores and macropores), which facilitated the free flow of gas within the coal samples. Additionally, HVEP treatment significantly reduced both the adsorption rate and the maximum gas adsorption capacity of the coal samples, indicating a strong inhibitory effect of HVEPs on gas adsorption. Conversely, HVEPs significantly increased the gas desorption capacity and desorption rate, suggesting that HVEPs facilitated the rapid desorption and release of gas from the coal samples. Furthermore, HVEP treatment increased the gas diffusion coefficient of the coal samples, which reduced their resistance to free diffusion after desorption and promoted gas extraction from the coal seam.

Source: Processes

DOI: 10.3390/pr13061662

Authors: Changxing Li, Guosheng Xu, Huanying Yao, Chengpeng Xin, Fei Liu

Institutions: Guizhou University of Engineering Science, University of Science and Technology of China, Wuhan University of Technology

Language: English

Topic: Coal Properties and Utilization

Subfield: Ocean Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Affordable and clean energy

Open Access status: gold

Estimated APC paid: $2,896