Title: Microscopic characteristics of the methane occurrence state in coal

Authors: Zhian Huang; Zhenzhen Ma; Rui Yang; Yukun Gao; Yinghua Zhang; Xuejiao Gong

Addresses: State Key Laboratory of High-Efficient Mining and Safety of Metal Mines, University of Science and Technology Beijing, Ministry of Education, Beijing, 100083, China; Work Safety Key Lab on Prevention and Control of Gas and Roof Disasters for Southern Coal Mines, Hunan University of Science and Technology, Xiangtan, 411201, China ' State Key Laboratory of High-Efficient Mining and Safety of Metal Mines, University of Science and Technology Beijing, Ministry of Education, Beijing, 100083, China ' State Key Laboratory of High-Efficient Mining and Safety of Metal Mines, University of Science and Technology Beijing, Ministry of Education, Beijing, 100083, China ' State Key Laboratory of High-Efficient Mining and Safety of Metal Mines, University of Science and Technology Beijing, Ministry of Education, Beijing, 100083, China; Work Safety Key Lab on Prevention and Control of Gas and Roof Disasters for Southern Coal Mines, Hunan University of Science and Technology, Xiangtan, 411201, China ' State Key Laboratory of High-Efficient Mining and Safety of Metal Mines, University of Science and Technology Beijing, Ministry of Education, Beijing, 100083, China ' Publicity Department, The People's Government of Sijiqing Town of Beijing, Beijing, 100195, China

Abstract: The regulation of methane occurrence is critical for gas control. Through liquid nitrogen adsorption, isothermal adsorption/desorption of methane and electrical experiments with undeformed and deformed coal, this paper studies the microscopic characteristics of methane occurrence. The results show: the median-pore-dominant deformed coal has less specific surface area and pore volume than the undeformed coal, which has mainly micropores and small pores; the deformed coal has greater methane absorption ability than the undeformed coal, and the negative influence of temperature on the former is more notable; the resistivity of deformed coal is three to seven times that of undeformed coal, and when adsorbing the resistivity of both coals decreases before being stable, whereas their dielectric constant rises first, then slightly declines. The results of the three experiments are in good accordance. The research is basic for coalbed gas and may provide a new thought for gas control.

Keywords: pore structure; adsorption-desorption; methane; electrical parameters.

DOI: 10.1504/IJMSI.2018.093908

International Journal of Materials and Structural Integrity, 2018 Vol.12 No.1/2/3, pp.151 - 178

Received: 29 Dec 2017
Accepted: 16 Apr 2018
Published online: 08 Aug 2018 *

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