Abstract:

The mixture of sulfur hexafluoride (SF₆) and nitrogen (N₂) is one of the most important emerging insulating media in the electric power industry, and it is of great significance to separate and recover SF₆ from scrap equipment and waste gas. The adsorption separation is environment-friendly and energy-saving, for the reason that it avoids the phase change process. However, SF₆ and N₂ are both inert nonpolar molecules, making the exploiting of adsorbents that can accurately capture SF₆ very challenging. The currently employed adsorption materials have evolved from traditional zeolites to new types of adsorbents, with metal-organic frameworks as the main type which are highly structurally tunable and can be predictably engineered to exhibit excellent selective adsorption of SF₆. This paper focuses on summarizing the structural characteristics, modulation strategies, separation performance and mechanisms of these materials, and at the same time points out the existing notable problems, including insufficient researches on the kinetic diffusion, mass transfer mechanism and materials stability, incomplete evaluation of the potential of the materials, etc., which should be paid attention to in the future research.

Key words: novel porous materials, adsorption separation, sulfur hexafluoride, metal-organic frameworks

摘要：

六氟化硫与氮气的混合气体是电力工业中最重要的新兴绝缘介质之一，从废弃设备和废气中分离回收六氟化硫具有重要意义。吸附法避免了高能耗的相变过程，具有绿色节能的特点，然而六氟化硫与氮气均为惰性的非极性分子，因此开发能够精准辨识六氟化硫的吸附剂极具挑战。目前获得研究的吸附分离材料已经从传统的沸石分子筛发展到以金属有机框架材料为主的新型吸附剂，这些材料具有结构的高度可调性，可以有预期地对其进行设计，从而体现出优异的选择性吸附六氟化硫的能力。本文重点总结了这些材料的结构特点、调控策略、分离性能及其机理，同时指出一些尚存的重要问题，如对扩散传质规律与材料稳定性的研究不足、对材料潜力的评价不够全面等，应当在未来的研究中引起重视。

关键词: 新型多孔材料, 吸附分离, 六氟化硫, 金属有机框架