Study on Elemental Mercury Oxidation by Non-thermal Plasma with Calcium Chloride Enhancement
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Converting of elemental mercury (Hg0) into oxidized mercury compounds is considered to be an effective method for prompting mercury removal of conventional flue gas treatment systems. The technology of non-thermal plasma (NTP) with CaCl2 treatment was utilized to oxidize Hg0 in this paper. The effects of input energy and different flue gas components like O2, NO and SO2 on Hg0 oxidation were investigated. The results showed that the Hg0 oxidation efficiency with CaCl2 treatment was increased obviously compare with single NTP treatment, and would be more than 90% when the input energy was 120 J/L. The O2 in simulated flue gas played an important role for mercury oxidation. The Hg0 oxidation efficiency and O3 outlet concentration were increased with the increase of O2 content. However, both NO and SO2 inhibited Hg0 oxidation due to their competitive consumption of O3 and O. Compare with single NTP technology, the effects of NO and SO2 on Hg0 oxidation under NTP with CaCl2 treatment were decreased obviously. The technology of Temperature-Programmed Decomposition and Desorption was utilized to analyze the mercury speciation adsorbed or deposited on AC and CaCl2 surface. The results concluded that the main Hg0 oxidation products by NTP with CaCl2 treatment were HgO, Hg2O and HgCl2, which indicated that the chlorine of CaCl2 surface was the main reason for enhancement of Hg0 oxidation.
KeywordsNon-thermal plasma Calcium chloride Elemental mercury Mercury chloride
This work was supported by the Doctor Special Foundation of Nanjing College of Information Technology (YB20170301), National Nature Science Foundation of China (51376046, 51576044), Natural Science Foundation of Jiangsu Province High Education (16KJB430034).
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