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STUDY OF THE FUNDAMENTALS OF MERCURY SPECIATION IN COAL-FIRED BOILERS UNDER SIMULATED POST-COMBUSTION CONDITIONS
Citation:
Ghorishi, S. STUDY OF THE FUNDAMENTALS OF MERCURY SPECIATION IN COAL-FIRED BOILERS UNDER SIMULATED POST-COMBUSTION CONDITIONS. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-99/026 (NTIS PB99-144347), 1999.
Description:
The report discusses a continuation of the study on mercury speciation initiated in the fiscal year 1997 (FY97). The previous study found that cupric oxide (CuO) and ferric oxide (Fe2O3) in the presence of hydrogen chloride (HCl) promote elemental mercury oxidation in simulated flue gas. Efforts were made in the FY98 study to better understand the speciation behavior of mercury under conditions simulating coal-fired boilers more closely than those for the FY97 study. In the follow-up FY98 work, calcium oxide (CaO) was added to the model fly ashes containing three components which were tested previously. The rate of oxidation of elemental mercury with four-component ashes was found to be much slower than that achieved with the three-component ashes. The detrimental effect of CaO on the Deacon reaction catalysts of CuO and Fe2O3 was demonstrated. Elemental mercury oxidation over three field-collected coal fly ash samples was studied, and only one sample containing high iron and copper content exhibited modest elemental mercury oxidation activity. A field-collected cement kiln dust sample containing 29 wt% calcium (Ca) exhibited catalytic behavior of oxidized elemental mercury similar to that of a Ca-containing model fly ash tested in FY97. The elemental mercury oxidation activity of cuprous chloride was investigated.