燃煤净烟气中共存杂质对膜法捕集CO2影响现状

膜法捕集CO₂是现役燃煤电厂碳减排的重要手段之一,在实际应用中膜法捕集系统通常适合安装在湿法脱硫系统下游,鉴于脱硫净烟气中的颗粒物及气态污染物难以完全脱除,同时水汽接近饱和状态,气相中的共存杂质以及吸收液组分与膜及膜材料相互作用,会对膜法捕集CO₂性能造成严重影响。本文综述了烟气中共存气态、颗粒物组分及液相吸收剂对膜分离、膜吸收宏观性能、膜微结构及材质的影响,以及燃煤脱硫净烟气环境下膜法捕集CO₂长期运行性能及变化规律的研究现状,指出了抑制膜失效的技术方法,以期为突破膜法捕集CO₂技术发展的瓶颈,实现膜的稳定高效运行提供参考。

Present situation of the effect of coexistent impurities in coal fired flue gas on CO2 capture by membranes

Membrane CO₂ capture is one of the important methods to reduce carbon emission in existing coal-fired power plants. In industrial application, the membrane capture system is usually suitable to be installed in the downstream of wet desulphurization system. However, it is difficult to remove all the fine particles and gaseous pollutants from the flue gas, and the water vapor is close to saturation. The co-existing impurities in the gas phase as well as the absorption liquid component have interaction with the membrane and membrane material, which will cause serious influence on the efficiency of membrane CO₂ capture. The effects of co-existing gaseous, particulate and liquid phase absorbents on membrane separation, macroscopic properties of membrane absorption, membrane microstructures and materials were reviewed in this paper. Furthermore, the characteristic of membrane capture performance in a long term operation under the desulfurized flue gas conditions were summarized, and the technical methods to inhibit membrane failure were pointed out. It will provide a reference for breaking through the bottleneck of membrane technology for capturing CO₂ and achieve stable and efficient operation of membrane.