EPRI's TOXECONTM Mercury Control Process 


    The Electric Power Research Institute (EPRI) earned a runner-up spot in the Environment category of the Wall Street Journal's 2004 Technology Innovation Awards for its patented TOXECONTM mercury control process-an improved means of reducing mercury emissions from coal-fired power plants. This promising new technology can capture more than 80% of the mercury in the flue gas.
    For many power plants, the most developed technology specifically designed for controlling mercury emissions is to inject a sorbent such as activated carbon into the flue gas. The sorbent bonds with the mercury and is removed along with the incombustible coal matter as fly ash. Fly ash can be recycled for beneficial purposes, such as a partial replacement for portland cement in the manufacture of concrete. 
    This not only avoids the need to dispose of the ash in a landfill but also eliminates the CO2 that would have been emitted during the production of the portland cement replaced by the ash. The problem for plants that inject a sorbent for mercury control is that the fly ash containing sorbent cannot be used in the manufacture of concrete. TOXECONTM separates the capture of the fly ash from the collection of the mercury containing sorbent, thus maintaining the usefulness of the fly ash.
    Another benefit of TOXECONTM is that it uses a small filter (called a baghouse) to capture the sorbent; therefore, the sorbent has greater contact with the mercury-containing flue gases than if it were simply mixed with the flowing gas. As a result, most power plant configurations would require significantly less sorbent in a TOXECONTM application than one where the sorbent is simply injected ahead of the plant's particulate control.
    Innovators worldwide are eligible for consideration in a dozen categories for the awards, termed the "Best and the Brightest". Selections are based on three major criteria: First, projects must address major challenges, for which new solutions would have wide impact. Second, top contenders must offer a truly novel solution, rather than just a modest improvement over existing practices. Finally, entries must be supported by rigorous data on their real-world performance.
    George Offen, technical executive at EPRI says, "We completed the first full-scale test of TOXECONTM in early 2002 and a longer-term full scale test, over about 9 months, this summer. We've now licensed five companies to use the system, and We Energies has purchased the technology to install in their Presque Isle Station in upper Michigan."
    The Presque Isle installation is co-funded under DOE's Clean Coal Power Initiative, a program that encourages the use of new technologies by sharing their cost with private industry, and is expected to come on line in 2005.
    Full-scale tests of the technology (co-funded by DOE with tests conducted by ADA-Environmental Solutions) were awarded an R&D 100 Award in 2003, and the process has been recognized by the U.S. EPA as a leading candidate for reducing emissions in reports to Congress and background documents for the mercury rules proposed on December 15, 2003.
    EPRI, with major locations in Palo Alto, CA., and Charlotte, N.C., was established in 1973 as an independent, non-profit center for public interest energy and environmental research.
    EPRI's collaborative science and technology development program now spans nearly every area of power generation, delivery and use. cl

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