Mechanism Analysis on the Effect of Liquid Water on Coal Adsorbing Methane
ZHANG Shi-yin
SANG Shu-xun
YANG Zhi-gang
Abstract：For studying the mechanism of effect of liquid water on methane adsorption on coal, the isothermal adsorption experiments were completed using dry, equilibrium moisture and wa-ter injection samples of different coal ranks. Based on the intermolecular force calculation the Virial equation was used to fit isothermal adsorption curves. The results show that wetting de-gree of coal matrix is a main factor of liquid water influencing methane adsorption on coal. For dry coal samples, intermolecular force between coal and methane is much higher than that be-tween methane molecules. The second Virial coefficient is lower and adsorption capacity is higher compared to other two types of coal samples. For equilibrium moisture coal samples, hydrogen bond force between coal and water is higher than their van der waals force, which re-sults in competition of gaseous water and methane molecules in the process of adsorption. The second Virial coefficient of the equilibrium moisture coal sample is slightly higher and its ad-sorption capacity is lower than that of the dry sample. For water injection coal samples, the sum of the long-rang force between coal and methane molecules and the short-range force be-tween methane and water molecules is less and equivalent to the intermolecular force among methane. The second Virial coefficient is the highest and its adsorption capacity is the lowest a-mong three types of samples. With the increasing of coal rank, the polarity and wetting degree of coal surface are decreased, and so does the second Virial coefficient.
Keywords：adsorptioncoal rankVirial equationmethaneintermolecalar force
Publication Date：2009-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 707-712 )