TOXECON RETROFIT FOR MERCURY AND MULTI-POLLUTANT CONTROL-ON THREE 90 MW COAL FIRED BOILERS

With the Nation's coal-burning utilities facing tighter controls on mercury pollutants, the U.S. Department of Energy is supporting projects that could offer power plant operators better ways to reduce these emissions at much lower costs. Sorbent injection technology represents one of the simplest and most mature approaches to controlling mercury emissions from coal-fired boilers. It involves injecting a solid material such as powdered activated carbon into the flue gas. The gas-phase mercury in the flue gas contacts the sorbent and attaches to its surface. The sorbent with the mercury attached is then collected by a particle control device along with the other solid material, primarily fly ash. We Energies has over 3,200 MW of coal-fired generating capacity and supports an integrated multi-emission control strategy for SO{sub 2}, NO{sub x} and mercury emissions while maintaining a varied fuel mix for electric supply. The primary goal of this project is to reduce mercury emissions from three 90 MW units that burn Powder River Basin coal at the We Energies Presque Isle Power Plant. Additional goals are to reduce nitrogen oxide (NO{sub x}), sulfur dioxide (SO{sub 2}), and particulate matter (PM) emissions, allow for reuse and sale of fly ash, demonstrate a reliable mercury continuous emission monitor (CEM) suitable for use in the power plant environment, and demonstrate a process to recover mercury captured in the sorbent. To achieve these goals, We Energies (the Participant) will design, install, and operate a TOXECON{trademark} (TOXECON) system designed to clean the combined flue gases of units 7, 8, and 9 at the Presque Isle Power Plant. TOXECON is a patented process in which a fabric filter system (baghouse) installed down stream of an existing particle control device is used in conjunction with sorbent injection for removal of pollutants from combustion flue gas. For this project, the flue gas emissions will be controlled from the three units using a single baghouse. Mercury will be controlled by injection of activated carbon or other novel sorbents, while NO{sub x} and SO{sub 2} will be controlled by injection of sodium based or other novel sorbents. Addition of the TOXECON baghouse will provide enhanced particulate control. Sorbents will be injected downstream of the existing particle collection device to allow for continued sale and reuse of captured fly ash from the existing particulate control device, uncontaminated by activated carbon or sodium sorbents. Methods for sorbent regeneration, i.e. mercury recovery from the sorbent, will be explored and evaluated. For mercury concentration monitoring in the flue gas streams, components available for use will be evaluated and the best available will be integrated into a mercury CEM suitable for use in the power plant environment. This project will provide for the use of a novel multi-pollutant control system to reduce emissions of mercury while minimizing waste, from a coal-fired power generation system