In response to the 2013 Mercury and Air Toxics Standards (MATS) regulations, many utilities have implemented mercury control technologies that include some form of bromine additive, whether pre-applied with the coal or injected downstream of the furnace as brominated-activated carbon. Mercury control is also of particular interest in oxy-fired combustion systems because it can amalgamate with aluminum surfaces in gas processing units slated for use in CO_2 separation processes. Some research groups have reported the potential for enhanced corrosion when mercury control additives are used when air, or oxy-firing coal. EPRI has reported that a large fraction of plants using bromine for mercury control have issues with air heater corrosion. To determine the impacts of CaBr_2 additive, pilot-scale mercury capture and corrosion testing was performed in the University of Utah's 1500 kW pulverized coal furnace. Both a PRB (Black Thunder) and a bituminous coal (Pratt - North River mine) were used and each combusted in an air-fired and oxy-fired environment. Results from this study verify that addition of CaBr_2 can significantly increase corrosion rate. However the extent of bromine additive impact is dependent on metal temperatures and HBr concentrations in the flue gas.
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