Sun Daorong, Li Zhen, Huang Shouqiang, Chi Jiawen, Zhao Songjian
School of Chemistry and Environmental Engineering, Jiangsu University of Technology, Changzhou, Jiangsu 213001, PR China.
School of Chemistry and Environmental Engineering, Jiangsu University of Technology, Changzhou, Jiangsu 213001, PR China.
J Hazard Mater. 2021 Oct 5;419:126423. doi: 10.1016/j.jhazmat.2021.126423. Epub 2021 Jun 22.
The low content of hydrogen chloride (HCl) in flue gas is difficult to meet the request of Hg removal. Here, a small amount of Cl was doped into the crystal lattice of CuO nanocrystals (Cl-CuO), presenting excellent Hg removal efficiency in chlorine-free coal combustion flue gas. SEM, XRD, BET, and XPS characterizations revealed well crystal morphology and structure of Cl-CuO catalyst. Besides, Cl-CuO had smaller sizes and higher BET surface area compared with CuO. Hg removal behaviors were studied using a lab-scale fixed-bed reactor. After doping Cl, Hg removal efficiency was improved obviously and could reach nearly 100% above 150 ℃, indicating chlorine incorporated into the catalyst lattice had a better role for Hg removal. Besides, gas composition effect on Hg removal was analyzed. Cl-CuO had high sulfur resistance capacity, and Hg removal efficiency can still reach above 90% even at 2000 ppm SO. O played a critical role in the Hg removal reaction. Furthermore, a plausible mechanism for Hg removal was analyzed. Doping Cl into the lattice of CuO nanocrystals was beneficial for the activation of molecular oxygen, and generated reactive oxygen species can further activate Cl to participate in the Hg removal reaction.
烟气中氯化氢（HCl）含量较低，难以满足汞去除的要求。在此，将少量氯掺杂到氧化铜纳米晶体（Cl-CuO）的晶格中，其在无氯煤燃烧烟气中表现出优异的汞去除效率。扫描电子显微镜（SEM）、X射线衍射（XRD）、比表面积分析仪（BET）和X射线光电子能谱（XPS）表征揭示了Cl-CuO催化剂良好的晶体形态和结构。此外，与CuO相比，Cl-CuO尺寸更小，比表面积更大。采用实验室规模的固定床反应器研究汞的去除行为。掺杂氯后，汞去除效率明显提高，在150℃以上可达到近100%，这表明掺入催化剂晶格中的氯对汞去除具有更好的作用。此外，分析了气体组成对汞去除的影响。Cl-CuO具有高抗硫能力，即使在2000 ppm SO₂ 时汞去除效率仍可达到90%以上。O在汞去除反应中起关键作用。此外，分析了一种合理的汞去除机理。将氯掺杂到氧化铜纳米晶体的晶格中有利于分子氧的活化，生成的活性氧物种可进一步活化氯以参与汞去除反应。
