469446 Mercury Oxidation over Cu-SSZ-13 Catalysts Under SCR Conditions for Power Plant Applications
In this study, SSZ-13 and Cu-exchanged SSZ-13 are compared to a commercial SCR catalyst with respect to their Hg oxidation activity under a variety of flue gas compositions and temperatures. A simulated flue gas environment is created through the combustion of methane in air in a high-temperature furnace. Other pollutants common to coal-combustion flue gas, such as HCl, SO2, NO, and NH3 are injected downstream of the furnace but upstream of the packed-bed reactor housing the catalyst. Concentrations of elemental and oxidized mercury were measured using a PS Analytical mercury analyzer to determine the amount of mercury oxidation. Initially, the flue gas composition was varied to examine the effect of individual flue gas components on Hg oxidation with the catalysts kept at 375°C, an intermediate SCR temperature. The compositions investigated include flue gas only (CO2+H2O+N2+O2), flue gas with HCl, with HCl+SO2 and with HCl+NO+NH3. Finally, the temperature effect was studied by varying the temperature between 300-450°C, representative of standard operating temperatures in SCR units for coal-fired power plants.