为研究Virial、V-d-W、R-K、S-R-K、P-R、童景山等6种工程常用气体状态方程中适合煤吸附CO₂压缩因子最优方程及快速计算模型，以3种不同变质程度煤样为研究对象，采用容量法实测了试验温度为30 ℃时应用以上6种方程所得煤的CO₂吸附量、CO₂吸附常数及吸附等温线。研究表明：与美国国家标准技术研究所（NIST）提供的CO₂压缩因子相比，采用Virial状态方程得到的CO₂压缩因子最大、绝对误差最小，为0.38%；吸附等温线拟合优度最高，CO₂吸附常数$a$值绝对值误差最小，确定出煤吸附CO₂压缩因子最优方程为Virial方程；同时，提出试验温度为30 ℃时，CO₂压缩因子一种简便快捷计算模型，经检验，该模型相对美国标准计算所得CO₂吸附常数$a$值绝对值误差最大不超过1%，且操作简便，快速精确。

In order to study the optimal equation and fast calculation model of CO₂ compression factor suitable for coal adsorption among 6 kinds of gas state equations commonly used in engineering, such as Virial, V-d-W, R-K, S-R-K, P-R and Tongjingshan, three coal samples with different metamorphism degrees were taken as research objects. The CO₂ adsorption capacity, CO₂ adsorption constant and adsorption isotherm of coal obtained by using the above six equations at the test temperature of 30 ℃ were measured by volumetric method. The research shows that: compared with the CO₂ compression factor provided by the National Institute of Standards and Technology (NIST), the maximum absolute error of CO₂ compression factor obtained by Viral state equation is 0.38%. The adsorption isotherm has the highest goodness of fit; the absolute value error of the measured CO₂ adsorption constant $a$ is the smallest, and the optimal gas state equation to determine the adsorption CO₂ compression factor of coal is the Viral equation. At the same time, a simple and fast calculation model of CO₂ compression factor is proposed when the test temperature is 30 ℃. After testing, the absolute error of the absolute value of the CO₂ adsorption constant $a$ calculated by the US standard is less than 1%, and the operation is simple, fast and accurate.