地质封存CO₂作为理想的减碳技术，有望成为缓解温室效应的重要手段，因此量化评估深部煤层CO₂地质封存潜力与研究超临界CO₂与深部煤岩之间相互作用成为了“双碳”背景下的研究热点。以焦作矿区九里山煤样为试验研究对象，分析了深部煤层超临界CO₂吸附与封存机理，分别开展了35和45 ℃下煤样的CO₂等温吸附试验，解释并校正了CO₂吸附等温线高压异常下拐现象，得到了不同温度下煤样的CO₂实际吸附量。提出了一种新方法计算CO₂地质封存量，能够校正吸附相体积造成的封存量计算误差，并能精确评估不同埋深煤层CO₂理论和有效封存量。研究结果表明：① 当高压吸附饱和时，煤样表面所有的吸附位被完全占据，此时吸附相体积和密度不再发生改变，吸附量应趋于稳定，但实验室测得的吸附量却在高压饱和阶段随压力增大而减小，这并不符合Langmuir吸附原理，因此必须对实验室测试的吸附等温线进行校正，才能应用于深部煤层CO₂封存量评估；② 煤中CO₂封存量主要由吸附和游离封存量组成，吸附封存量需要采用吸附相密度和Gibbs吸附量进行反算，游离封存量则需要掌握煤中游离相占据的孔隙体积，它只能根据煤中孔隙总体积减去吸附相体积进行计算，因此，吸附相是精确评估吸附和游离封存量的决定性因素；③ 采用修正的煤层CO₂地质封存量化方法，以焦作修武研究区800～2 000 m深部煤层为例，得出其单位质量煤中CO₂理论封存量为1.52～2.16 mmol/g，CO₂有效封存总量为11.19×10⁹ m³，换算为封存总质量为21.97 Mt。本研究案例不仅校正了吸附试验数据的物质平衡错误，而且考虑了吸附相占据孔隙空间对游离封存量的影响，这对深部煤层CO₂地质封存量精准评估具有重要的应用意义。

Geological storage of CO₂ as an idea carbon reduction technology is expected to become an important means of mitigating the greenhouse effect. Therefore, quantitatively assessing the potential of geological storage of CO₂ in deep coal seams and investigating the interaction between supercritical CO₂ and deep coal rocks have become a hot research topic. Taking Jiulishan coal sample from Jiaozuo mining area in Henan, China as the experimental research object, we analyse the mechanism of supercritical CO₂ adsorption and sequestration in deep coal seams, carry out CO₂ isothermal adsorption experiments of the coal samples at 35 ℃ and 45 ℃, explain and correct the error of negative adsorption isotherms under high pressure, and obtain the actual adsorption amount of CO₂ of the coal sample at different temperatures. Here, we propose a new method for calculating CO₂ geological storage capacity, which can not only correct the storage capacity miscalculation caused by Gibbs adsorption, but also can accurately evaluate CO₂ theory and effective storage capacity in different burial depths of coal seams. results show that: ① In theory, adsorption saturation means that all adsorption sites have been occupied, the volume and density of the adsorption phase have stabilized, and the adsorption amount should no longer changes. However, all adsorption isotherms measured in the laboratory show that the adsorption amount decreases with the increase of pressure under high-pressure saturation stage, which does not conform to the Langmuir adsorption principle. Therefore, the adsorption isotherm measured in the laboratory must be corrected before it can be applied to the assessment of CO₂ storage capacity in deep coal seams; ② The CO₂ storage capacity in coal mainly consists of the adsorption and free CO₂ amount. The adsorption CO₂ amount needs to be calculated using the adsorption phase density and Gibbs adsorption amount, while the free CO₂ amount needs to know the pore volume occupied by the free phase in coal. It can only be calculated based on the total pore volume in coal minus the adsorption phase volume. Therefore, the adsorption phase is the decisive factor for accurately evaluating the adsorption and free CO₂ storage capacity; ③ Using a modified CO₂ geological storage quantification model and taking the 800-2000 m deep coal seam in the Xiuwu research area of Jiaozuo mining area as an example, it is calculated that The theoretical storage capacity of CO₂ per unit mass of coal is 1.52−2.16 mmol/g, The total effective storage capacity is 11.19×10⁹ m³, which is equivalent to 21.97 Mt. This case not only corrected the mass balance miscalculation of Gibbs adsorption data, but also considered the impact of adsorption phase occupying pore space on free storage capacity, and thus, it has important implication for improving the accuracy of predicting CO₂ geological storage capacity in deep coal seams.