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The Chinese Journal of Process Engineering ›› 2023, Vol. 23 ›› Issue (10): 1446-1457.DOI: 10.12034/j.issn.1009-606X.222344

• Research Paper • Previous Articles     Next Articles

Preparation of calcium-based composite absorbent and simultaneous removal performance of SOx and NOx from flue gas

Yang LI1,2,  Yang LIU2,  Changming LI3,  Liangliang FU1,  Jian YU2*   

  1. 1. College of Chemical Engineering, Shenyang University of Chemical Technology, Shenyang, Liaoning 110142, China 2. State Key Laboratory of Multiphase Complex System, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China 3. School of Ecology and Environment, Beijing Technology and Business University, Beijing 100048, China
  • Received:2022-09-16 Revised:2023-02-06 Online:2023-10-28 Published:2023-10-30
  • Contact: Jian Yu yujian@ipe.ac.cn

钙基复合吸收剂的制备及烟气同时脱硫脱硝性能

李洋1,2， 刘洋2， 李长明3， 付亮亮1， 余剑2*   

  1. 1. 沈阳化工大学化学工程学院，辽宁 沈阳 110142 2. 中国科学院过程工程研究所多相复杂系统国家重点实验室，北京 100190 3. 北京工商大学生态环境学院，北京 100048
  • 通讯作者: 余剑 yujian@ipe.ac.cn

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Abstract: In order to solve the technical problems of simultaneous desulfurization and denitrification of flue gas at ultra-low temperatures (<120℃) by dry process, this work prepared several calcium-based composite absorbents by coupling different strong oxidants with lime of high specific surface area, which can realize the efficient simultaneous removal of sulfur oxides (SOx) and nitrogen oxides (NOx) from flue gas at ultra-low temperature (<120℃). The results of desulfurization and denitrification performance evaluation of calcium-based composite absorbers with different oxidant types and loadings showed that the addition of strong oxidants not only improved the desulfurization performance of Ca(OH)2 but also achieved simultaneous denitrification with Ca(OH)2. The type and amount of oxidant had a significant influence on the simultaneous desulfurization and denitrification of flue gas, and the appropriate moisture and oxygen contents of flue gas were beneficial to improve the desulfurization and denitrification efficiency. According to the characterization results of crystal structure, thermal decomposition, microstructure, and specific surface area of calcium-based composite absorbers before and after the flue gas purification reaction, it can be found that SO2 and NO are first oxidized by strong oxidants, and then react with hydrated lime to generate corresponding sulfates and nitrates, improving the desulfurization and denitrification efficiency. This study is expected to provide a new purification material and process for the upgrading of the intrinsic engineering process or purification of small industrial boilers to achieve ultra-low emission requirements.

Key words: Simultaneous desulfurization and denitrification, Calcium-based absorbers, oxidizer, Reaction mechanism

摘要： 针对干法超低温(<120℃)烟气同时脱硫脱硝技术难题，本工作将强氧化剂与高比表面积消石灰耦合制备钙基复合吸收剂，实现了超低温(<120℃)烟气干法高效同时脱除硫氧化物(SOx)和氮氧化物(NOx)。不同氧化剂种类和负载量的钙基复合吸收剂烟气脱硫脱硝性能评价结果表明，强氧化剂的加入不仅提升了消石灰脱硫性能，还能与消石灰协同实现同时脱硝；氧化剂种类、添加量对烟气同时脱硫脱硝影响显著，而且烟气具有适当的水分含量和氧含量有利于提升脱硫脱硝效率。根据钙基复合吸收剂烟气净化反应前后的晶相结构、热分解、微观形貌、比表面积等表征结果可发现，SO2和NO首先被强氧化剂氧化，然后与消石灰反应生成相应的硫酸盐和硝酸盐，提高了脱硫和脱硝效率。本研究有望为烟气超低排放升级改造或小型工业锅炉烟气净化提供一种新的净化材料与工艺。

关键词: 同步脱硫脱硝, 钙基吸收剂, 氧化剂, 反应机制