Citation

Hong L, Wang W, Gao D, Guo Y, Ma H. China Saf. Sci. J. 2022; 32(4): 51-58.

Copyright

(Copyright © 2022, China Occupational Safety and Health Association, Publisher Gai Xue bao)

DOI

10.16265/j.cnki.issn1003-3033.2022.04.008

PMID

unavailable

Abstract

In order to study coal adsorption theory and adsorption mechanism of coalbed methane, six coal samples of different ranks were selected for low⁃temperature N2 adsorption experiments to explore CPSD of filled N2 molecules in coals. Then, experimental isotherm characteristics were analyzed through density functional theory (DFT) and theory of volume filling of micropore (TVFM), and critical filling pressure (CFP) and CPSD for micropore fillings were obtained. Finally, relative pressure segmentation method was used to verify the results by fitting of Langmuir equation⁃Dubinin⁃Astakhov (D⁃A) equation⁃ Brunauer⁃Emmet⁃Teller (BET) equation. The results show that N2 adsorption/ desorption isotherm of coal samples, from low to high rank, transitions from type II to type I. And proportion of N2 molecules present in forms of micropore filling and monolayer adsorption in low⁃rank coals is greater than that of high⁃rank ones. CPSD decreases first and then increases as coal rank goes from low to high. The higher the rank is, the smaller CPSD range of 6 coal samples will be, which is between 1. 61-2. 19 nm. © 2020 China Safety Science Journal. All rights reserved.

Language: zh