PDF《基于石灰石法脱硫浆液的 K2S2O8 氧化 Hg0 性能》

第50 卷第

1 期 中南大学学报(自然科学版) Vol.

50 No.1

2019 年1月Journal of Central South University (Science and Technology) Jan.

2019 DOI: 10.11817/j.issn.1672-7207.2019.01.004 基于石灰石法脱硫浆液的 K2S2O8 氧化 Hg0 性能 田立江,刘秉坤,李杰,沈晓玲 (中国矿业大学 环境与测绘学院,江苏 徐州,221116) 摘要:利用改进的 Hg0 液相氧化反应器,考察脱硫浆液 pH、K2S2O8 浓度、金属离子浓度、入口烟气 Hg0 和SO2 质量浓度对氧化 Hg0 性能的影响.研究结果表明:低pH 有利于 K2S2O8 高效氧化 Hg0 ,pH 在5.0 左右时,Hg0 氧 化效率能维持在 83%以上.K2S2O8 浓度在

5 mmol/L 时,Hg0 氧化效率高于 90%并呈现很好的运行稳定性.Mn2+ , Ag+ 或Co2+ 的存在均可提高 Hg0 氧化性能, 但提高 K2S2O8 浓度至

5 mmol/L 也能达同等效果. Hg0 氧化效率随浆液 Fe3+ 浓度的增加先增加后趋于稳定,当Fe3+ 浓度增至 2.0 mmol/L 以上时,Hg0 氧化效率再次增加;

Mg2+ 的存在反 而使 Hg0 性能有所降低.Hg0 氧化效率随烟气 SO2 质量浓度的升高先增加后逐渐下降,最高可达 85.57%,且SO2 的存在增强了系统 Hg0 氧化的稳定性. 关键词:石灰石?石膏法;

脱硫浆液;

燃煤烟气;

汞氧化 中图分类号:X511 文献标志码:A 文章编号:1672?7207(2019)01?0023?06 Characteristics of Hg0 oxidation by K2S2O8 based on limestone-gypsum desulfurization slurry TIAN Lijiang, LIU Bingkun, LI Jie, SHEN Xiaoling (School of Environment Science &

Spatial Informatics, China University of Mining and Technology, Xuzhou 221116, China) Abstract: The effects of slurry pH, K2S2O8 concentration, metallic ion concentration, inlet flue gas Hg0 and SO2 mass concentration on Hg0 oxidation were studied based on the modified liquid reactor. The results show that low value of slurry pH is propitious to oxidize Hg0 , and the oxidation efficiency can maintain above 83% when the value of pH keeps around 5.0. The oxidation efficiency of Hg0 can be higher than 90% and keeps stable steadily when K2S2O8 concentration reaches

5 mmol/L. The existence of Mn2+ , Ag+ or Co2+ can improve the Hg0 oxidation capability while it can acquire the same outcome through increasing the K2S2O8 concentration to

5 mmol/L. With the increase of Fe3+ concentration, the Hg0 oxidation efficiency rises firstly, then becomes steady, but the efficiency rises again when the Fe3+ concentration is higher than 2.0 mmol/L. The existence of Mg2+ does not enhance the Hg0 oxidation but weakens the oxidation capability. Hg0 oxidation efficiency rises firstly and then descends gradually, and the highest efficiency can reach 85.57% with the increase of flue gas SO2 mass concentration. The existence of SO2 can enhance the stabilization of the system about Hg0 oxidation. Key words: limestone?gypsum method;

desulfurization slurry;

coal fired flue gas;

mercury oxidation 收稿日期:2018?01?31;

修回日期:2018?05?15 基金项目(Foundation item): 国家自然科学基金资助项目(51208502) (Project(51208502) supported by the National Natural Science Foundation of China) 通信作者:田立江,博士,副教授,从事烟气除尘脱硫脱硝除汞技术研究;

E-mail: [email protected] 中南大学学报(自然科学版) 第50 卷24 我国的能源格局长期以来一直以煤炭为主,煤炭 的使用量居于世界首位. 到2016 年, 中国原煤产量达 34.1 亿t,全国发电装机容量为

164 575 万kW,比上 年末增长 8.2%,其中火电装机容量

105 388 万kW, 增长 5.3%[1] .预计到