(455c) Quantifying Shifts in Trace Element Emissions from Coal-Fired Power Plants

Coal contains a variety of trace elements that are volatalized when the coal is combusted in coal-fired power plants (CFPPs). These trace elements are emitted to the environment in the exhaust gas, ashes, or in wastewater effluents. The partitioning of trace elements to the gas, solid, or liquid phase is determined to a large extent by installed air pollution control devices (APCDs). CFPPs have changed their installed APCDs and the coal they combust in response to changes in environmental regulations. We combine data from the U.S. Energy Information Administration and United States Geological Survey to build a model that will estimate the solid, liquid, and gas phase emsisions of seven trace elements (As, Cl, Se, Hg, Br, B, and Pb) from all US CFPPs with a capacity greater than 10 MW. We use this model to quantify how the installation of new APCDs has shifted trace element emisssions from the gas phase to the solid and liquid phase over past decades. We also calculate the impact of the shift towards low-sulfur coals on trace elements in the coal combusted at CFPPs and how alternative, hypothetical environmetnal compliance strategies would have produced different trace element emissions patterns.