天然煤体吸附甲烷的非均匀特征研究

王江芳; 王辰; 冯增朝

天然煤体吸附甲烷的非均匀特征研究

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出版历程
- 发布日期: 2021-07-19

Study on heterogeneous characteristics of methane adsorption by natural coal

摘要

摘要: 为了寻求非均匀势阱煤体甲烷吸附量精准评价的方法，依据朗格缪尔吸附动力学过程，对存在非均匀势阱的天然煤体吸附甲烷特征进行了理论分析与实验研究。研究结果表明：在煤与甲烷吸附平衡状态，煤中甲烷分子倾向于吸附在势阱较深的吸附位置上，不同深度势阱的覆盖率符合以吸附压力与温度为参数的Logistic（S型）曲线规律；天然煤样的朗格缪尔参数a均随吸附压力增加呈增大趋势，朗格缪尔参数b随吸附压力的增加呈减小趋势；不同种类的天然煤样吸附势阱分布的差异性，导致不同吸附压力下的朗格缪尔参数a与b的不同；基于朗格缪尔方程的天然煤体甲烷吸附量计算值在低吸附压力下偏高，在高吸附压力下偏低；利用非均匀势阱等温吸附量计算方法可以使煤中甲烷吸附量的计算误差大幅降低。
- 吸附势阱 /
- 非均匀 /
- 吸附压力 /
- 甲烷吸附量 /
- 计算精度
Abstract: In order to find a method for accurately evaluating the methane adsorption capacity of coal with non-uniform potential wells, this paper based on the Langmuir adsorption kinetic process, carried out theoretical analysis and experimental research on the characteristics of methane adsorption by natural coal with non-uniform potential wells, and obtained the following conclusion: in the equilibrium state of coal and methane adsorption, the methane molecules in coal tend to be adsorbed on the deeper adsorption sites of the potential well, and the coverage of potential wells at different depths conforms to the Logistic（Ｓ－ｔｙｐｅ）ｃurve law with adsorption pressure and temperature as parameters. The Langmuir parameter a of natural coal samples all increase with the increase of adsorption pressure, and the Langmuir parameter b decreases with the increase of adsorption pressure. The difference in the distribution of the adsorption potential wells of different types of natural coal samples leads to the different Langmuir parameters a and b under different adsorption pressures. The calculated value of methane adsorption in natural coal based on the Langmuir equation is higher at low adsorption pressure, and lower at high adsorption pressure. The calculation method of the non-uniform potential well isotherm adsorption capacity can greatly reduce the calculation error of the methane adsorption capacity in coal.
- adsorption potential well /
- non-uniform /
- adsorption pressure /
- methane adsorption capacity /
- calculation accuracy

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参考文献(18)

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