Mercury speciation measurements on a 10 MW(sub e) coal-fired boiler simulator

摘要

The current trends towards deregulation of electric utilities, air toxic regulations and stringent fine particulate emissions reflect an increased need for coal-based research. In response, Babcock and Wilcox invested in the state-of-the-art 100 million Btu/hr (10 MW, equivalent) Clean Environment Development Facility (CEDF) located in Alliance, Ohio. The representative combustion conditions, flow patterns and residence times permit direct scale-up of CEDF test results to commercial boilers and pollution control devices. In cooperation with the U.S. Department of Energy and the Ohio Coal Development Office within the Ohio Office of Development, B&W is employing the CEDF to conduct a five-year project aimed at the development of practical, cost-effective strategies for reducing the emissions of hazardous air pollutants from coal-fired boilers. The project specifically targets the control of mercury, the trace element under close scrutiny by the EPA. Due to the various forms of mercury emissions from coal-fired boilers, accurate mercury speciation measurements are required to develop mercury control strategies. Current uncertainty in the accuracy and mercury speciation capability of mercury sampling methods led B&W to use both EPA Method 29 and the Ontario Hydro procedures to measure mercury emissions from CEDF pollution control devices. A comparison of the speciated mercury emissions is presented.