Research progress of Metal-Organic Frameworks (MOFs) in CO2 capture and transformation
LIU Fengsheng,DONG Hao,WANG Tao,HUANG Wei
社会和工业现代化的进步,CO2及其他温室气体的排放日益增加,导致温室效应严重、自然灾害频发。为了减少碳排放,大力发展碳捕集、利用与封存技术(CCUS)势在必行。目前,常用的CO2捕集方法包括吸附分离法、化学吸收法、膜分离法、CO2直接转化等。其中,开发高效、稳定的吸附剂与催化材料是各种捕集技术优化的关键。
详细综述了金属有机骨架材料(Metal-Organic Frameworks,MOFs)在CO2捕集和转化中的应用,分析了目前研究的最新进展,揭示了应用过程存在的问题和解决方法。其中双金属MOFs较单金属具有更多的金属缺陷位及L酸含量,在CO2吸附分离和催化反应中表现出良好的优势。功能化修饰法可以针对不同CO2捕集技术的需求进行对应改性,拥有较高的成功率,尤其是后功能化法,因其改性方法简单、结构维持较好被广泛应用于CO2捕集的各种方法中。前功能化法是最理想的MOFs改性方法,尤其是配体功能化,可以从结构上改变MOFs对CO2的亲和性,但其结构的维持是目前研究的一大难点。MOFs纳米流体吸收剂的制备可有效增加吸收剂内部的传热传质,改善传统纳米颗粒的团聚现象,有利于稳定悬浮液的形成,增加了CO2吸收量,但吸收剂的黏性控制是目前研究的壁垒。另外,作为膜分离法中的填充材料,MOFs因其良好的相容性及丰富的表面官能团,可以有效地提高膜的选择性,同时本身对CO2的高吸附可以提高膜的CO2容量,但MOFs膜的机械性能及循环稳定性还需进一步优化。虽然目前MOFs应用于CO2捕集技术的研究很多,但利用MOFs的CO2捕获系统和经济学分析的文献有限,本研究从MOFs的制备成本、CO2捕集成本和再生成本出发,试图揭示MOFs的化学性质与CO2捕获的过程经济性关系。
With the progress of social and industrial modernization, the emission of carbon dioxide (CO2) and other greenhouse gases is increasing, resulting in serious greenhouse effect and frequent natural disasters. In order to reduce carbon emissions, it is imperative to develop carbon capture, utilization and storage technology (CCUS). At present, the commonly CO2 capture methods and transformation methods include chemical absorption method, adsorption separation method, membrane separation method, and CO2 catalytic reaction, etc. Among them, the development of efficient and stable adsorption and catalytic materials is the key to the optimization of various capture technologies. In this paper, the application of metal-organic frameworks (MOFs) in CO2 capture and conversion is reviewed in detail, the latest progress of current research is analyzed, and the problems and solutions in the application process are revealed. Compared with single metal MOFs, bimetallic MOFs have better metal defect sites and L acid content, showing good advantages in CO2 adsorption separation and catalytic reaction. The functional modification method can be modified according to the needs of different CO2 capture technologies, and has a high success rate, especially the post-functionalization method, which is widely used in CO2 capture due to its simple modification method and good structure maintenance. Pre-functionalization is the most ideal modification method for MOFs, especially ligand functionalization, which can essentially change the affinity of MOFs to CO2. However, the maintenance of MOFs structure is a major difficulty in current research. The preparation of MOFs nanofluid absorbent can effectively increase the heat and mass transfer inside the absorbent, improve the agglomeration of traditional nanoparticles, facilitate the formation of stable suspension, and increase the amount of CO2 absorption. But the viscosity control of absorbent is the barrier of current research. In addition, as a filling material in membrane separation method, MOFs can effectively improve the selectivity of membrane due to its good compatibility and abundant surface functional groups. At the same time, the high CO2 adsorption of MOFs can improve the CO2 capacity of the membrane, but the mechanical properties and cyclic stability of MOFs membrane need to be further optimized. Although there are many studies on CO2 capture technology by MOFs, the literature on CO2 capture system and economic analysis is limited. Starting from the preparation cost, CO2 capture cost and regeneration cost of MOFs, this study attempts to reveal the relationship between the chemical properties of MOFs and the process economy of CO2 capture.
Metal-Organic Frameworks;CO2 capture; adsorption; absorption; catalytic of CO
主办单位:煤炭科学研究总院有限公司 中国煤炭学会学术期刊工作委员会