Liu Xiaolong, Zou Yang, Geng Ran, Zhu Tingyu, Li Bin
CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Innovation Academy for Green Manufacture, Chinese Academy of Sciences, Beijing 100190, China.
Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China.
ACS Omega. 2021 Oct 22;6(43):28804-28812. doi: 10.1021/acsomega.1c03572. eCollection 2021 Nov 2.
In this work, steel slag slurry was used in combination with O oxidation for the simultaneous removal of SO and NO in a laboratory-scale wet flue gas desulfurization process. The effects of the oxidation temperature, steel slag concentration, initial SO concentration, and pH value on the desulfurization and denitrification efficiencies were studied. The results showed that the highest NO removal efficiency occurred at an oxidation temperature of 90 °C. With an increase of the oxidation temperature above 90 °C, the denitrification efficiency decreased due to the decomposition of NO. The effect of the SO concentration on denitrification was complicated. When the concentration of SO was 500 ppm, generation of SO promoted the absorption of NO. However, higher SO concentrations strengthened the competitive absorption of SO and NO . In the pH range of 8.5-4.5, the denitrification efficiency was maintained at about 96%. The component analyses of the aqueous solution and the solid residue were conducted to investigate the compositions of the absorption products. The results showed that NO and SO were the major anions in the aqueous solution. The nitrogen balance was analyzed to be 95.8%, clearly illustrating the migration and transformation path of nitrogen. In the solid residue, most alkaline substances were consumed, and the final products were mainly CaSO and FeO. Accordingly, the reaction mechanism of simultaneous desulfurization and denitrification using steel slag combined with ozone oxidation was proposed.
在这项工作中，在实验室规模的湿法烟气脱硫过程中，钢渣浆液与臭氧氧化联合用于同时去除SO和NO。研究了氧化温度、钢渣浓度、初始SO浓度和pH值对脱硫和脱硝效率的影响。结果表明，在氧化温度为90℃时，脱硝效率最高。当氧化温度高于90℃时，由于NO的分解，脱硝效率降低。SO浓度对脱硝的影响较为复杂。当SO浓度为500 ppm时，SO的生成促进了NO的吸收。然而，较高的SO浓度增强了SO和NO的竞争吸收。在pH值为8.5 - 4.5的范围内，脱硝效率维持在96%左右。对水溶液和固体残渣进行了成分分析，以研究吸收产物的组成。结果表明，NO和SO是水溶液中的主要阴离子。氮平衡分析为95.8%，清楚地说明了氮的迁移和转化途径。在固体残渣中，大部分碱性物质被消耗，最终产物主要是CaSO和FeO。据此，提出了钢渣与臭氧氧化联合同时脱硫脱硝的反应机理。
