1. Mercury Control for Power Plants Arun Mehta, George Offen, Ramsay Chang, Richard Rhudy Presented to the 2003 Annual ACERC Conference Salt Lake City, UT February 20, 2003

2. 2 EPRI Mercury Control R&D Program Program started with developing understanding of factors affecting mercury emissions Studies of flue gas parameters controlling the effectiveness of control strategies Development & demonstration of a range of options

3. 3 Key Partners Power Producers Allegheny, Cinergy, Duke Power, First Energy, GRE, LG&E, Minnesota Power, MidAmercan Energy Co, NIPSCo, Ontario Power Generation, PG&E NEG, PSEG, Southern Company, TVA, TXU, We Energies, Xcel Agencies NETL/DOE, EPA, ICCI, NDIC Contractors and Laboratories ADA-ES, Apogee, EERC, ISGS, URS Suppliers –Hamon RC, Norit, EnviroCare, EEC

4. 4 Mercury Reductions for Power Plants – Performance Overview -- Bituminous 20-95%, depending on NOx, SO 2 control –SD/BH or SCR/FGD with high Cl  highest  Hg Options to increase Hg removal –Activated carbon injection (ACI) furthest developed –Oxidation catalysts or chemical additives may increase capture by SO 2 controls – under development SCR catalyst age and size may not be critical factors (?) Re-emissions is growing concern

5. 5 Mercury Reductions for Power Plants – Performance Overview – Low Rank Coals Typically  Hg < 25% –Includes plants with SO 2 control ACI again furthest developed, but –Ahead of ESP < 60-70% –Ahead of FF??? Tests planned 2003 –SD/BH impedes ACI performance Possible solutions –Oxidation catalysts ahead of SO 2 control –Chemical additives to enhance capture in SO 2 control or via ACI –Fixed structures coated with sorptive material

6. 6 Full-scale ACI Test Sites Test SiteCoalParticulate ControlStatus Gaston Alabama Power* LSEBHot-side ESP COHPAC FF Completed 2001(2003 long term) Pleasant Praire WE Energies* PRBESPCompleted 2001 Abbott U of Illinois HSEBESPCompleted 2001 Brayton Point PG&E NEG* LSEBESPCompleted 2002 Salem Harbor PG&E NEG* LSEBESPIn Progress Stanton Great River Energy ND lignite SD-BHCompleted 2002 (2003 planned) Laskin Minnesota Power PRBWet particulate scrubber Completed 2002 *DOE-NETL PRDA Projects

7. 7 Field Results – Hg By ACI Ahead of ESPs 0 10 20 30 40 50 60 70 80 90 051015202530 Injection Concentration (lb/Macf) Hg Removal (%) Full-Scale Test (PRB) Full-Scale Test (Lo S Bit) Full-Scale Test (Hi S Bit) Pilot Sites (8) $7M/yr for 500MW

8. 8 SD-BH Reduced Effectiveness of ACI 0 10 20 30 40 50 60 70 80 90 100 02468 Injection Concentration (lb/MMacf) % Hg Removal FGD, SD + BH HOK, SD + BH LAC, SD + BH IAC, SD + BH Average BH

9. 9 Hg o Oxidation Activity (Sub-Bituminous Coal)

10. 10 Mercury Removal Across Wet Scrubber Dependent on Salt Chemical Type Potential impacts –Air heater pluggage –Opacity increase –Scrubber water chloride increase

11. 11 Parallel Plates with sorbent surface Gas Flow MerCAP TM Concepts Carbon honeycomb Currently focusing on post SD/BH with W. fuels 10’ plates believe  90%  Hg Developmental technology

12. 12 Mercury Control: What Next? Next? Long-term (3 months to one year) full-scale ACI tests (with NETL/DOE) –EPRI actively seeking partners – hosts and contractors Short-term full-scale ACI/chemical injection tests on western fuels Emerging technologies (some with NETL/DOE) –Chemical additives –MerCAP™ and other fixed structures/beds –Novel sorbents (from EPA, EPRI, others) –Mercury oxidation catalyst field pilot testing –Other concepts, IECs?