Catm Annual Report Listing of Catm Projects

Project Description The EERC is performing fundamental research to understand mechanisms responsible for conversion of mercury to other chemical species within combustion and gasification flue gas. This research is imperative for development and validation of improved mercury emission measurement, monitoring, and control. Several tasks are devoted to understanding mercury transformations. Unburned carbon particles from two carbon-rich fly ashes derived from full-scale coal-fired utility boilers are being separated from inorganic ash fractions. The fly ash samples were selected based on a high propensity for effective capturing of mercury. Carbon concentrates are being characterized in detail to determine which physical and chemical properties may be important in capturing mercury. A portable bench-scale entrained-flow reactor (EFR) is being used to determine mercury oxidation and particulate formation rates as a function of coal type (at least two highly differing in rank and composition), flue gas residence time, and flue gas temperature. Sulfur species in unburned carbon from coal or tire rubber are being explored as possible reaction sites for oxidizing and stabilizing gaseous mercury. Chemical additives are being investigated in combination with tetrasulfide flue gas injection to determine the impact on mercury oxidation and capture. Finally, the effects of SO 2 , SO 3 , and HCl on mercury speciation in the presence of selective catalytic reduction catalyst material and a coal flue gas environment will be tested in a bench-scale system. Goal The overall goal of this project is to develop a fundamental understanding of Hg transformations in flue gas for the purpose of developing more effective mercury control strategies. Specific objectives to accomplish this goal include: