CaO基吸附剂捕集CO2及其抗烧结改性研究进展

Research progress of calcium-based adsorbents for CO2 capture and anti-sintering modification

  • 摘要: 利用CaO基吸附剂直接从高温烟气中捕集CO2因成本低、吸附性能好等优点成为CCUS(碳捕集、利用与封存)的重要技术之一。但CaO基吸附剂在碳酸化/煅烧吸脱附循环过程中存在易烧结的问题,导致其吸附性能急剧下降。本研究针对CaO基吸附剂全面总结了其吸附CO2的动力学、热力学及烧结机理,并重点综述了世界各国研究者在CaO基吸附剂抗烧结改性方面所做的研究,指出了各种方法的优点及其局限性。结果表明,水合作用改性可使吸附剂崩塌而获得更大的比表面积;酸溶液改性会在制备过程产生更多的气体和小分子物质提高吸附剂孔隙率;掺杂改性可以促进CaO对CO2的吸附和扩散,还可作为骨架分离CaO颗粒。经比较,掺杂改性工艺简单、性能好,是比较有前景的改性方法,以含钙固废制备抗烧结改性吸附剂是发展方向。

     

    Abstract: As one of the important solid adsorbents for CCUS (CO2 Capture, Utilization and Storage), the calcium-based adsorbents have attracted wide attention because they can directly capture CO2 from high-temperature flue gas and have a low cost and good adsorption performance. However, the calcium-based adsorbents are easy to sinter during repeated adsorption-desorption cycles, which will cause a sharp drop in adsorption performance. In this work, the reaction kinetics, thermodynamics and the sintering mechanism of the calcium-based adsorbents were summarized. At the same time, the advantages and limitations of various anti-sintering modification methods were compared and analyzed. The results show that the hydration modification can cause the adsorbent to collapse and obtain a larger surface area. The acid solution modification will generate more gas and small molecules during the preparation process to increase the porosity of the absorbent. Doping modification can promote the adsorption and diffusion of CO2, and the dopant can be acted as a framework to separate CaO particles. It can be concluded that the doping modification is a relatively promising modification method due to its simple process and good performance; and the use of calcium-containing solid waste for preparation of anti-sintering modified adsorbents has great potential for application.

     

/

返回文章
返回