吸附分离CH4/N2是实现低浓度煤层气高效利用的重要手段。针对目前变压吸附存在N2吸附量和选择性低的问题，本项目基于N2分子与具有空电子轨道的金属离子间的强相互作用，提出以离子液体负载型金属有机骨架(IL@MOF)为吸附剂。通过调控MOF拓扑结构、表面特性、有机配体及金属离子种类，强化N2与吸附剂间的相互作用，提升N2吸附量；进一步调节IL负载量对吸附剂孔隙结构进行精细调控，提高CH4分子扩散阻力，降低其吸附量，从而实现CH4/N2的高效分离。从低浓度煤层气吸附相平衡数据出发，研究各因素对低浓度煤层气吸附相平衡特性的影响规律，揭示IL-MOF协同作用对低浓度煤层气分离性能的影响机制，建立考虑两者协同作用的气体吸附相平衡方程，阐明IL@MOF结构特性—IL-MOF协同作用—CH4/N2分离性能之间的内在联系。本项目体现了多学科的交叉融合，其成果将为变压吸附分离低浓度煤层气技术的发展奠定基础。

Adsorption separation of CH4/N2 mixture is an important method for efficient utilization of low-concentration coal bed methane. To solve the problem of low N2 adsorption quantity and selectivity in traditional pressure swing adsorption, this project proposes ionic liquid supported metal-organic frameworks (IL@MOF) can be used as an efficient adsorbent, base on the strong interaction between N2 molecules and metal ions with empty electron orbital. By controlling topology, surface properties, species of ligands and metal ions of metal-organic frameworks, enchancing the interaction between N2 molecules and adsorbent, thus increasing the N2 adsorption quantity. Furthermore, the pore structures of adsorbent are finely controlled by adjusting IL loading, which increase the diffusion resistance of CH4 molecules and decrease its adsorption quantity, so as to realize the efficient separation of CH4/N2 mixture. On the basis of the phase equilibrium data, this project focuses on exploring the influence of various factors on the phase equilibrium properties of low-concentration coal bed methane, revealing the influence mechanism of synergy effect of IL-MOF on the separation properties of low-concentration coal bed methane, establishing the phase equilibrium equation with synergy effect of IL-MOF, illuminating the internal relations among the structural properites of the IL@MOF, synergy effect of IL-MOF and separation properties of CH4/N2 mixture. This project shows the intercross and coalescence among multi-subjects, the achievements will promote the development of pressure swing adsorption in the separation of low-concentration coal bed methane.