Title: Pore structure and its impact on CH₄ adsorption capability and diffusion characteristics of normal and deformed coals from Qinshui Basin

Authors: Shou-qing Lu; Yuan-ping Cheng; Wei Li; Liang Wang

Addresses: National Engineering Research Center of Coal Gas Control, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China ' National Engineering Research Center of Coal Gas Control, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China ' Faculty of Safety Engineering, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China ' Key Laboratory of Gas and Fire Control for Coal Mine, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China

Abstract: In this study, the pore structure, adsorption/desorption kinetics and thermodynamics of normal and deformed coals are compared. The total pore volume and porosity of deformed coal are 2.84 to 2.91 times greater than those of normal coal, whereas the micropore volume and specific surface area of normal coal are 1.15 to 1.35 times greater than those of deformed coal. Langmuir volume of normal coal is greater than that of deformed coal. Δσ of normal coal is slightly greater than that of deformed coal which indicates that the unit area of normal coal CH₄ adsorption capacity is also greater than that of deformed coal. At the early stage of the desorption process, the mass diffusivity of deformed coal is ten times greater than that of normal coal. Then it decreases rapidly, while that of normal coal decreases very slowly. At last, it will be less than that of normal coal. [Received: January 5, 2013; Accepted: April 30, 2013]

Keywords: normal coal; deformed coal; pore structure; surface free energy; mass diffusivity; methane; CH4; adsorption capability; desorption; kinetics; thermodynamics.

DOI: 10.1504/IJOGCT.2015.070042

International Journal of Oil, Gas and Coal Technology, 2015 Vol.10 No.1, pp.94 - 114

Received: 20 Jan 2013
Accepted: 30 Apr 2013
Published online: 26 Jun 2015 *

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