Laboratory of Carbon Capture and Efficient Utilization,School of Chemistry and Chemical Engineering,InnerMongolia University of Science & Technology
Inner Mongolia Key Laboratory of CoalChemical Engineering & Comprehensive Utilization,Inner Mongolia University of Science & Technology

MgO吸附剂因其成本低廉、来源广泛、再生能耗低等优势在CO2吸附领域应用广泛,但比表面积低限制了其吸附性能。以高表面积、多级孔结构的含膦多孔有机聚合物POL-PPH3为载体,采用浸渍煅烧法和超声煅烧法制备得到POL-PPH3负载的MgO吸附剂(MgO/POL-PPH3),用于CO2捕集。探究制备方法、煅烧温度、煅烧时间等制备条件对MgO/POL-PPH3吸附剂上CO2吸附性能的影响。研究发现,浸渍煅烧法优于超声煅烧法,且随着煅烧温度和煅烧时间增加,MgO/POL-PPH3样品上CO2吸附容量逐渐降低。采用浸渍煅烧法,煅烧温度300℃,煅烧时间1h时,MgO/POL-PPH3-300-1吸附剂上获得最优CO2吸附量,达0.55mmol/g。在组成为12%CO2,其余为氮气的模拟烟道气中,MgO/POL-PPH3-300-1吸附剂上CO2吸附容量达0.02mmol/g,200℃吸附60min,370℃脱附15min条件下,该吸附剂稳定循环使用5次后,CO2吸附容量仍保持不变。结合N2物理吸附、热重、FT-IR、XRD、SEM-EDX等表征手段,阐明MgO/POL-PPH3吸附剂上吸附CO2的构效关系。动力学模型分析表明采用浸渍煅烧法不同煅烧温度下获得的3种吸附剂上CO2吸附以物理吸附为主,而不同煅烧时间下获得的3种吸附剂包括MgO/POL-PPH3-300-1吸附剂上CO2吸附行为以化学吸附为主。高比表面积及多级孔道结构有利于暴露更多的活性位点及CO2传输与扩散,进而增大MgO/POL-PPH3吸附剂的CO2吸附容量。MgO在载体上高度分散也有利于增强与CO2的接触,以加快CO2吸附速率。

MgO adsorbent has been widely used in the field of CO2 adsorption due to its advantages of low cost, wide source and low regenerative energy consumption, but its adsorption performance is limited by its low surface ratio. In this paper, a phosphine-containing porousorganic polymer POL-PPH3 with high surface area and hierarchical pore structure was used as a carrier, and POL-PPH3-loaded MgO adsorbent (MgO/ POL-PPH3) was prepared by impregnation-calcination and ultrasonic calcinations to obtain the MgO adsorbent (MgO/POL-PPH3) for CO2 capture. Effects of preparation conditions such as preparation method, calcination temperature and calcination timeon the CO2 adsorption performance on MgO/ POL-PPH3 adsorbents were investigated. It is found that the impregnation calcination methodis superior to the ultrasonic calcination method, and the CO2 adsorption capacity on the MgO/ POL-PPH3 samples gradually decreases withthe increase of calcination temperature and calcination time. The optimum CO2 adsorption capacity of 0.55 mmol/ g on MgO/ POL-PPH3-300-1 adsorbent is obtained when the impregnation calcination method is used with a calcination temperature of 300 ℃ and a calcinationtime of 1 h. In the simulated flue gas with a composition of 12% CO2 and the rest of nitrogen, the CO2adsorption capacity of 0.02 mmol/ gon the MgO/ POL-PPH3-300-1 adsorbent is obtained. Under the conditions of adsorption at 200 ℃ for 60 min and desorption at 370 ℃for 15 min, the CO2 adsorption capacity of this adsorbent remains unchanged after five times of stable recycling. The structure-property relationship of CO2 adsorption on MgO/ POL-PPH3 adsorbent was elucidated by combining N2 physical adsorption, thermogravimetric, FT-IR, XRD, SEM-EDX and other characterization methods. Kinetic modelling analysis of the CO2 adsorption behaviours on the three adsorbents obtained at different calcination temperatures by impregnation calcination method is dominated by physical adsorption, whereas thoseof the three adsorbents obtained at different calcination times, including the MgO/ POL-PPH3-300-1 adsorbent, are dominated by chemical adsorption. The high specific surface area and hierarchical pore structure are conducive to the exposure of more active sites and thetransport and diffusion of CO2, which in turn increases the CO2 adsorption capacity of the MgO/ POL-PPH3 adsorbent, and the high dispersion of MgO on the support is also benificial to the enhancement of the contact with CO2 to accelerate the CO2 adsorption rate.

内蒙古科技大学基本科研业务费专项资金资助项目(2023QNJS061,2023QNJS064,2024XKJX002)

田甜,张学奇,王玉清,等.含膦多孔有机聚合物负载氧化镁的制备及其CO2吸附性能[J].洁净煤技术,2024,30(4):146-156.

TIAN Tian,ZHANG Xueqi,WANG Yuqing,et al.Preparation and CO2 adsorption performance of a phosphine-containingporous organic polymer supported magnesium oxide[J].Clean Coal Technology,2024,30(4):146-156.