The adsorption of coal to CH4, CO2 and its multi-component gas is one of the basic parameters of CO2-ECBM technology, and it is also the basis for evaluating CO2 storage and CH4 gas production. Aiming at the cumbersome and time-consuming experiment of coal adsorption mixed gas, the adsorption isotherms of CO2, CH4 and their mixed gases were measured by isothermal adsorption experiment and the adsorption coefficients of mixed gases a, b and CO2 volume fraction were proposed. By fitting the equation, the prediction method of CO2 and CH4 mixed gas adsorption amount is obtained. The main conclusions are as follows: the equilibrium time of CO2 adsorption by C13 coal in Huainan Mining Area is about 24 h, which is much higher than the adsorption equilibrium time of CH4; the adsorption capacity of C13 coal for CO2 is more than twice that of CH4. The adsorption amount of C13 coal to the mixed gas increases with the increase of CO2 volume fraction; the adsorption constant a, b values and carbon dioxide volume fraction are in quadratic function relationship. According to the fitting equation, the Langmuir equation can be used to calculate the adsorption capacity of CO2 and CH4 mixed gas in any volume ratio.%煤对CH4、CO2及其多元混合气体吸附量是CO2-ECBM技术的基础参数之一,也是评价CO2封存量和CH4产气量的基础.针对煤吸附混合气体试验繁琐、耗时长的问题,采用等温吸附试验分别实测了煤样对CO2、CH4及其混合气体的吸附等温线,并提出了混合气体吸附常数a、b与CO2体积分数的拟合方程,得出了CO2和CH4混合气体吸附量预测方法.主要结论如下:淮南矿区C13煤吸附CO2的平衡时间约为24 h,远高于对CH4的吸附平衡时间;C13煤对CO2的吸附能力是CH4的2倍以上.C13煤对混合气体的吸附量随CO2体积分数的增大而增大;吸附常数a、b值与二氧化碳体积分数符合二次函数关系,可根据拟合方程,结合朗格缪尔方程计算任意体积比的CO2和CH4混合气体吸附量.
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