A Review of DOE/NETL’s Mercury Control Technology R&D Program for Coal-Fired Power Plants

Mercury exists in trace amounts in coal. In the United States, coal-fired power plants emit about 48 tons of mercury and are the largest point source of emissions. The U.S. Environmental Protection Agency has determined the need to control mercury emissions from power plants. In addition, several legislative proposals have been introduced in the 108 Congress to reduce mercury emissions from the electric-utility sector. Recognizing the potential for mercury regulations, the U.S. Department of Energy/National Energy Technology Laboratory (DOE/NETL) has been carrying out a comprehensive mercury research and development (R&D) program since the early 1990s. Working collaboratively with industry, academia, and EPA, DOE/NETL has helped to advance the understanding of the formation, distribution, and capture of mercury. However, uncertainty remains, particularly related to the overall cost and effectiveness of controlling mercury from a diverse population of coal-fired boilers, as well as the ultimate fate of mercury once it is removed from the flue gas. This paper provides a summary of the status of DOE/NETL’s mercury R&D program, with a focus on the development of advanced emission control technology. The paper also briefly describes research directed at the characterization of mercury in coal utilization by-products (e.g., fly ash) and the transport and transformation of mercury in power plant plumes.