Abstract: The application of M⁃MOF⁃74 series in CO₂ removal of natural gas was studied. The skeleton model of M⁃MOF⁃74 was established. The adsorption of pure CO₂ gas and CO₂/CH₄ mixed gas in M⁃MOF⁃74 series adsorbent was calculated by GCMC method. The results showed that the order of adsorption of CO₂ by M⁃MOF⁃74 adsorbent was Mg⁃MOF⁃74 > Ni⁃MOF⁃74 > Co⁃MOF⁃74 > Fe⁃MOF⁃74 > Cr⁃MOF⁃74 > Mn⁃MOF⁃74.When adsorbing mixed gases, the adsorption amount of CO₂ by each adsorbent is consistent with that of pure CO2 adsorption, and the adsorption amount of CH₄ is: Mg⁃MOF⁃74>Ni⁃MOF⁃74≈Co⁃MOF⁃74≈Fe⁃MOF⁃74≈Cr⁃MOF⁃74≈Mn⁃MOF⁃74. The law of isosteric heat of gas on M⁃MOF⁃74 is the same as that of adsorption capacity, indicating that the interaction between gas and M⁃MOF⁃74 is the main factor affecting the adsorption amount. The selectivity of each adsorbent to mixed gas: Ni⁃MOF⁃74>Co⁃MOF⁃74>Fe⁃MOF⁃74>Mn⁃MOF⁃74>Cr⁃MOF⁃74>Mg⁃MOF⁃74. Comprehensive comparison of CO₂ adsorption capacity, regeneration energy consumption, selectivity coefficient and other parameters, Ni⁃MOF⁃74 is more suitable for the adsorption and separation of CO₂ in natural gas.

Key words: Molecular simulation, Adsorption separation, Adsorption capacity, Isosteric heat, Selectivity

摘要： 研究了M⁃MOF⁃74系列吸附剂在天然气脱CO₂中的应用，建立了M⁃MOF⁃74系列吸附剂的骨架模型，并利用GCMC方法计算了CO₂纯组分气体以及CO₂/CH₄混合气体在M⁃MOF⁃74系列吸附剂上的吸附。结果表明，M⁃MOF⁃74系列吸附剂对CO2的吸附量从大到小的顺序为Mg⁃MOF⁃74＞Ni⁃MOF⁃74＞Co⁃MOF⁃74＞Fe⁃MOF⁃74＞Cr⁃MOF⁃74＞Mn⁃MOF⁃74；吸附混合气体时，CO₂吸附量规律与纯CO₂吸附量一致，CH₄吸附量从大到小的顺序为Mg⁃MOF⁃74＞Ni⁃MOF⁃74≈Co⁃MOF⁃74≈Fe⁃MOF⁃74≈Cr⁃MOF⁃74≈Mn⁃MOF⁃74；气体在M⁃MOF⁃74系列吸附剂上的等量吸附热的大小规律与吸附量规律相同，说明气体与M⁃MOF⁃74系列吸附剂之间的相互作用是影响吸附量的主要因素。吸附剂对混合气体的选择性从大到小的顺序为Ni⁃MOF⁃74＞Co⁃MOF⁃74＞Fe⁃MOF⁃74＞Mn⁃MOF⁃74＞Cr⁃MOF⁃74＞Mg⁃MOF⁃74。综合比较CO₂吸附量、再生能耗、选择性系数等参数，Ni⁃MOF⁃74更适合吸附分离天然气中的CO₂。

关键词: 分子模拟, 吸附分离, 吸附量, 等量吸附热, 选择性系数