Adsorption characteristics of micropores in coal at low temperature and pressure

doi:10.16265/j.cnki.issn1003-3033.2018.12.013

Abstract

Abstract: To explore the relationship between the power source of coal and gas outburst and coal microporous adsorption, coal samples low-temperature nitrogen adsorption experiments were carried out by means of a physicochemical adsorber. Based on the theory of micropore filling and multi-layer adsorption, the demarcation point between micropore filling and adsorption on mesoporous surface of coal was analyzed by using the non-linear fitting method. The micropore filling rate of coal and the pressure of gas in the process of desorption were calculated with the aid of the Dubinin-Radushvich (D-R) equation and the ideal gas equation of state. The results show that the demarcation point between micropore filling and multi-layer adsorption of coal is the relative pressure of 0.01, that more than 48% of the microporous volume is filled with gas (methane), that the pressure generated by the gas during desorption is over 30.38 MPa, which will lead to the fragmentation of the coal, induce a release of a large amount of gas, and provide a power source for coal and gas outburst.

Key words: coal, nitrogen adsorption experiment, micropore filling, multi-layer adsorption, adsorption isotherm, desorption pressure

CLC Number:

X936

HONG Lin, GAO Dameng, WANG Jiren, ZHENG Dan, DU Yuanhong. Adsorption characteristics of micropores in coal at low temperature and pressure[J]. China Safety Science Journal, 2018, 28(12): 77-82.

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