煤体中CH_(4)与CO_(2)竞争吸附特性研究

Study on Competitive Adsorption Characteristics of CH_(4) and CO_(2) in Coal

为探究CO_(2)驱替煤层CH_4过程吸附机理,采用等温吸附方法,使用CH_4、CO_(2)单组分及不同配比的混合气体,研究了不同吸附压力下煤体竞争吸附特性。试验结果表明:单组分气体在煤中的吸附量与体应变呈非线性关系。混合气体在吸附过程中,混合气中CO_(2)的浓度越大,煤体膨胀越显著,混合气的吸附量越大;混合气压力越大,混合气总吸附量越大,CH_4和CO_(2)在煤中的竞争吸附由CO_(2)的强吸附能力主导,混合气吸附过程中,CO_(2)吸附量始终大于CH_4。

In order to explore the adsorption mechanism of CO_(2)flooding coal seam CH_(4)process,the isothermal adsorption method is used to study the competitive adsorption characteristics of coal body under different adsorption pressures by using CH_(4),CO_(2)single component and mixed gas with different propor⁃tions.The results show that there is a nonlinear relationship between the adsorption amount of single compo⁃nent gas in coal and the volume strain.In the adsorption process of mixed gas,the greater the concentration of CO_(2)in the mixed gas,the more significant the coal expansion,the greater the adsorption capacity of the mixed gas.The greater the pressure of the mixed gas,the greater the total adsorption capacity of the mixed gas.The competitive adsorption of CH_(4)and CO_(2)in coal is dominated by the strong adsorption capacity of CO_(2).During the adsorption process of mixed gas,the adsorption capacity of CO_(2)is always greater than that of CH_(4).