针对沼气分离过程中甲烷浓度低、能耗高的问题，设计和合成了具有高比表面积、高吸附容量的新型高性能吸附剂，并从分子模拟和实验方面研究了其吸附性能。以金属-有机骨架材料为例，详细综述了纳微结构材料用于气相分离的计算化学方法进展，为生物甲烷气体系的分离材料的设计与开发，提供了理论指导。采用混合配体方法，成功合成了具有能选择性脱除含甲烷体系(CH4/CO2)中的CO2的ZIF-9-67杂化膜，在此基础上，研究了气体在纳微结构材料中的扩散机理及温度对分离性能的影响；采用计算与实验相结合的方法，研究了液相体系中小分子苯胺和大分子甲基橙和亚甲基蓝在MOFs材料中的吸附机理，提出了设计新型纳微结构材料的新策略，为扩展MOFs在液相体系中吸附分离应用奠定了一定的基础。 以MOFs材料为研究对象，研究开发了一种常温常压快速制备金属有机骨架材料的方法，为大规模运用MOFs材料进行CH4/CO2分离的研究和应用提供了实验基础。通过层层自组装等方法在氧化钛晶须上进行MOF材料的包覆，制备了MOF/TiO2复合材料，在此基础上，进一步开展了TiO2负载型材料的研究，实现了氧化钛表面微环境的构筑。通过溶液环境的调控，实现了Cu-BTC材料多孔到无孔结构的快速可逆转变，开发了MOF材料微环境的调控方法。 针对离子液体吸收CO2速率慢的问题，研究了离子液体在担载和微乳化后的CO2的吸附性能，从非平衡热力学角度出发，负载和微乳化两种方法能够显著提高气液的接触界面，通过增加传质面积和减小平衡化学位的方法提高了CO2的吸收/解吸速率，在生物甲烷净化方面有较好的应用前景。Towards the problems of low concentration of methane and high energy cost during the separation of biogases, novel high-performance adsorbents with high surface area as well as high adsorption capacity were designed and synthesized, and their adsorption properties were investigated by a combination of molecular simulations and experimental measurements. Taking metal-organic frameworks (MOFs) as examples, we comprehensively reviewed the important advances in the computational methodologies developed with respect to MOFs up to now, which can provide the theoretical guidance for the design of novel materials in connection with the separation of biomethane systems. In addition, the mixed-ligands method was used to successfully synthesize a ZIF-9-67 hybrid membrane, and it can selectively remove CO2 from CH4/CO2 mixtures. Furthermore, the adsorption mechanisms of guests with different sizes in MOFs were also probed, and some new strategies were proposed for the design of novel nanoporous materials. These can provide a foundation for extending the adsorption/separation applications of MOFs under liquid-phase environments.On the basis of the above findings, a method for rapid preparation of MOFs under ambient conditions was developed, which offers an experimental base in a large-scale study of MOFs for CH4/CO2 separation. A MOF/TiO2 composite was also prepared via layer-by-layer self-assembly methods in which MOFs were wrapped up on the TiO2 whiskers. By probing the properties of such a composite, the construction of microenviorments on the TiO2 surface was achieved. Additionally, a reversible transition between porous and nonporous structures of Cu-BTC was realized through regulating the conditions in the solutions, leading to a novel method for tailoring the microenviroments of MOFs.Considering the drawbacks of ionic liquids with a slow rate for CO2 absorption, their adsorption properties after the supported and microemulsion treatments were examined. From the non-equilibrium thermodynamics point of view, it was found that the two methods can significantly increase the gas/liquid contacting interface. By increasing the mass-transfer area and decreasing the chemical potential, the absorption/desorption rate can be greatly enhanced, showing promising applications for biogas purification.
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