Performance of a pilot-scale wet electrostatic precipitator for the control of sulfuric acid mist

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• 作者：Jiayu Huang ; Hongmei Wang ; Yingjie Shi…
• 关键词：Wet electrostatic precipitator (WESP) ; Sulfuric acid mist ; Wall ; cooled collection electrode ; Ultrafine aerosols ; Plasma ; induced effect ; Condensation ; induced aerosol growth
• 刊名：Environmental Science and Pollution Research
• 出版年：2016
• 出版时间：October 2016
• 年：2016
• 卷：23
• 期：19
• 页码：19219-19228
• 全文大小：1,527 KB
• 刊物类别：Earth and Environmental Science
• 刊物主题：Environment
  Environment
  Atmospheric Protection, Air Quality Control and Air Pollution
  Waste Water Technology, Water Pollution Control, Water Management and Aquatic Pollution
  Industrial Pollution Prevention
  
• 出版者：Springer Berlin / Heidelberg
• ISSN：1614-7499
• 卷排序：23

文摘

The use of a wet electrostatic precipitator (WESP) is often regarded as a viable option to reduce sulfuric acid mist emitted from the wet flue gas desulfurization (WFGD) tower in coal-fired power plants. In this study, a pilot-scale wet electrostatic precipitator equipped with a wall-cooled collection electrode is investigated for the control of sulfuric acid mist from a simulated WFGD system. The results show that due to partial charging effect, the removal efficiency of sulfuric acid aerosol decreases when the aerosol size decreases to several tens of nanometers. Moreover, due to the plasma-induced effect, a large number of ultrafine sulfuric acid aerosols below 50 nm formed at a voltage higher than 24 kV inside the WESP. The percentages of submicron-sized aerosols significantly increase together with the voltage. To minimize the adverse plasma-induced effect, a WESP should be operated at a high gas velocity with an optimum high voltage. Even at a high flue gas velocity of 2.3 m s−1, the mass concentration and the total number concentration of uncaptured sulfuric acid aerosols at the WESP outlet are as low as ca. 0.6 mg m−3 and ca. 104 1 cm−3 at 28 kV, respectively. The corresponding removal efficiencies were respectively higher than 99.4 and 99.9 % and are very similar to that at 1.1 and 1.6 m s−1. Moreover, the condensation-induced aerosol growth enhances the removal of sulfuric acid mist inside a WESP and enables a low emission concentration of ca. 0.65 mg m−3 with a corresponding removal efficiency superior to 99.4 % even at a low voltage of 21 kV, and of ca. 0.35 mg m−3 with a corresponding removal efficiency superior to 99.6 % at a higher voltage level of 26 kV.