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NETL supports research on integrated, multi-task modeling and experimentation that is helping to meet Administration goals for reducing mercury emissions from power plants. The Laboratories' trace metal capture research directly addresses initiatives of the 2005 Clean Air Mercury Rule and Energy Policy Act, and 2002 Global Climate Change and Clear Skies Initiatives. By simulating and studying coal-derived gases, researchers have been able to examine numerous sorbents and their ability to capture mercury and arsenic. Onsite research in the area of trace metal capture now is developing low-cost and effective mercury removal techniques to meet national goals of capturing more than 90 percent of mercury emissions from U.S. coal-fired plants by 2010. This research has led to several NETL patents for trace metal capture - conceived and studied at in-house laboratories - that are now licensed and being demonstrated commercially.

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The Photochemical Oxidation (PCO™) Process is a promising low-cost technology that uses ultraviolet light to capture, oxidize, and enhance the removal of elemental mercury from the flue gas treatment systems of coal-fired power plants. Preliminary bench and field tests have achieved a greater than 90 percent oxidation and capture rate in simulated flue gas streams containing elemental mercury. NETL researchers received the 2005 Award for Excellence in Technology Transfer from the Federal Laboratory Consortium for the PCO method, which has been licensed to Powerspan Corp. for commercial application with subbituminous and lignite fuels.

The Thief Process is a cost-effective alternative to the use of activated carbon injection (ACI) for removing mercury from flue gas. The Thief Process involves extracting partially combusted coal from the plant furnace and re-injecting it as a sorbent. Activated carbons are expensive, ranging from $500–3,000/ton compared to $90–200/ton for Thief carbon sorbents. Laboratory-, bench-, and pilot-scale tests, as well as field tests demonstrate that extracted carbon sorbents are comparable to activated carbons for mercury capture efficiency. The Thief Process has been licensed to Mobotec USA.

PG Sorbents for Trace Metal Capture from Coal-Derived Gases represent the most recent collaborative R&D effort in this area, resulting in a Cooperative Research and Development Agreement (CRADA) between NETL and Johnson Matthey, PLC. Power Generation (PG) sorbents are used to remove mercury, arsenic, and selenium in coal-derived fuel gas streams from coal gasification at high temperatures. NETL has set the foundation for the joint effort by performing initial testing with various mercury-capturing sorbents.

Onsite facilities used to process and analyze sorbents and gases include laboratory-scale and bench-scale packed-bed reactors, catalysts, and photochemical techniques. These state-of-the-art facilities and techniques make it possible for advances to be made in the trace metal treatment and control of coal-derived gas streams.