多孔碳结构调控及其在二氧化碳吸附领域的应用

CO_2大量排放引发的温室效应已成为当今世界面临的重要环境问题。燃煤发电厂是CO_2的集中排放源,其排放量约占总排放量的42%,因此,燃煤发电厂烟道气中CO_2的高效捕集迫在眉睫。吸附技术操作简便、能耗低,易于实际应用,被认为是最具前景的烟道气CO_2捕集技术。近年来,多孔碳吸附剂因原料来源广、理化特性可控性强以及目标吸附质适应性高等优点,成为当前CO_2捕集技术的研究热点。综述了近年来多孔碳的制备方法,物理活化法、化学活化法、炭气凝胶法和模板法等,以及制备方法对孔径结构、杂元素掺杂缺陷和多孔碳表面性能的调控;并阐述了孔径结构、元素掺杂和表面官能团改性对CO_2吸附量、循环稳定性、烟道气中CO_2吸附选择性的影响,归纳了多孔碳吸附在实际应用中亟需解决的问题和关键技术。可进一步深入研究机理,协同制备出更高效且适用于CO_2吸附的多孔碳。

Porous carbon structure control and its application in the field of carbon dioxide adsorption

The greenhouse effect caused by the massive emission of CO 2 has become a significant environmental problem in the world today.Coal-fired power plant is a centralized source of CO 2 emissions,which accounts for about 42%of the total emissions.Therefore,efficient capture of CO 2 in the flue gas of coal-fired power plants is imminent.The adsorption technology is considered as the most promising CO 2 capture technology for flue gas,due to simple operation,low energy consumption,easy practical application.In recent years,porous carbon adsorbents have become the current research hotspot of CO 2 capture technology due to the advantages of a wide range of raw materials,strong controllability of physical and chemical properties,and high adaptability of target adsorbates.In this paper,the preparation methods of porous carbons such as physical activation,chemical activation,carbon aerogel and template methods in recent years were reviewed.The effects of preparation methods on pore structure,element doping defects and surface properties of porous carbon were investigated.Besides,the effects of different pore structure,element doping and surface functional group modification on CO 2 adsorption capacity,cycle stability,and CO 2 adsorption selectivity in the flue gas were also described.The problems and critical technologies of porous carbon adsorption in practical application were summarized.The mechanism can be further studied in the future to prepare more efficient porous carbon for CO 2 adsorption.