Study on gas adsorption characteristics of coal under high temperature and high pressure atmosphere

doi:10.16265/j.cnki.issn1003-3033.2024.02.1453

Abstract

Abstract:

Deep mining faces high temperature and pressure environments. In order to understand the adsorption gas characteristics of deep coal bodies, an isothermal adsorption experiment was conducted to study the coal's adsorption characteristics under different temperature and pressure conditions. The experiment examined both macro and micro perspectives of the coal's adsorption behavior, molecular dynamics isothermal adsorption simulation and theoretical analysis. The research results are as follows. When the gas pressure is low, the difference between the absolute adsorption capacity and the excess adsorption capacity is not significant at different temperatures. When the gas pressure is high, the difference between the absolute adsorption capacity and the excess adsorption capacity increases with the increase in temperature. In the process of gas pressure increasing from 0 to 20 MPa, the amount of gas adsorbed by coal is divided into three stages. The growth pattern consists of a rapid increase during the initial stage, followed by short-term stability in the middle stage, and a gradual decline in the later stage. The equal adsorption heat and adsorption capacity of coal meet the exponential function relationship. The temperature-pressure adsorption model based on the equivalent adsorption heat deduction can predict the quantity of isothermal adsorption gas under any temperature and pressure conditions, and the relative error between the measured and predicted values is 10%.

Key words: high temperature and high pressure, adsorption gas of coal, adsorption characteristics, absolute adsorption capacity, excess adsorption, equal adsorption heat

CLC Number:

X936

SHEN Xiaojing, YUE Jiwei, LIANG Yuehui, WANG Chen, XU Jinlin, HAN Qijun. Study on gas adsorption characteristics of coal under high temperature and high pressure atmosphere[J]. China Safety Science Journal, 2024, 34(2): 176-184.

Figures/Tables 16

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真密度/ (g·cm^-3)	视密度/ (g·cm^-3)	孔隙率/%	坚固性系数	煤的工业分析
真密度/ (g·cm^-3)	视密度/ (g·cm^-3)	孔隙率/%	坚固性系数	水分%	灰分/%	挥发分/%
1.42	1.39	5.67	0.94	1.03	8.09	16.98

温度/K	h	i	R²
303.15	0.123 67	13.036 78	0.974 72
323.15	0.125 01	13.183 58	0.975 81
343.15	0.126 73	13.316 5	0.977 17
363.15	0.128 17	13.452 48	0.978 28

V/ (mL·g^-1)	d	C	相关系数	Q_st/ (kJ·mol^-1)
5	-807.25	16.215 5	0.997 73	6.711 3
10	-836.11	17.140 84	0.997 66	6.951 3
15	-875.64	17.835 47	0.997 54	7.280
20	-933.15	18.501 57	0.997 29	7.758