Removal of Elemental Mercury from Flue Gas by Thermally Activated Ammonium Persulfate in A Bubble Column Reactor

Publisher Website
Google Scholar
Abstract
In this article, a novel technique on removal of elemental mercury (Hg0) from flue gas by thermally activated ammonium persulfate ((NH4)2S2O8) has been developed for the first time. Some experiments were carried out in a bubble column reactor to evaluate the effects of process parameters on Hg0 removal. The mechanism and kinetics of Hg0 removal are also studied. The results show that the parameters, (NH4)2S2O8 concentration, activation temperature and solution pH, have significant impacts on Hg0 removal. The parameters, Hg0, SO2 and NO concentration, only have small effects on Hg0 removal. Hg0 is removed by oxidations of (NH4)2S2O8, sulfate and hydroxyl free radicals. When (NH4)2S2O8 concentration is more than 0.1 mol/L and solution pH is lower than 9.71, Hg0 removal by thermally activated (NH4)2S2O8 meets a pseudo-first-order fast reaction with respect to Hg0. However, when (NH4)2S2O8 concentration is less than 0.1 mol/L or solution pH is higher than 9.71, the removal process meets a moderate speed reaction with respect to Hg0. The above results indicate that this technique is a feasible method for emission control of Hg0 from flue gas.
Funding Information
  • National Natural Science Foundation of China (51206067)
  • Ministry of Education of the People's Republic of China (20123227120016)
  • Key Laboratory of Efficient and Clean Energy Utilization, College of Hunan Province, Changsha University of Science and Technology