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Hg Monitoring And Monitoring WESTAR Fall Meeting

Measuring Total And Speciated Mercury In Process Gas Emissions Solid Sorbent Based Methods: US EPA 324 and FAMS. Hg Monitoring And Monitoring WESTAR Fall Meeting Mercury and Air Quality – Sources, Effects, and Controls San Diego, California September 22, 2005 Bob Brunette

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Hg Monitoring And Monitoring WESTAR Fall Meeting

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  1. Measuring Total And Speciated Mercury In Process Gas EmissionsSolid Sorbent Based Methods: US EPA 324 and FAMS Hg Monitoring And Monitoring WESTAR Fall Meeting Mercury and Air Quality – Sources, Effects, and Controls San Diego, California September 22, 2005 Bob Brunette Frontier Geosciences Inc 414 Pontius Avenue North Seattle, Washington 98109 Bobb@frontiergeosciences.com 206 957 1461

  2. Frontier Flue Gas Adsorbent Mercury Speciation - Topics Covered - • Frontier Geosciences Inc • Hg Control Systems – Do They Work? • Existing Hg Sampling Methods • History Of Solid Sorbent Methods: US EPA 324 and FAMS • Measuring Total and Speciated Hg In Process Gas • US EPA 324 and FAMS Methods • US EPA 1631 & Applications To Coal-Fired Utility • Hg Control Systems Evaluated • Conclusions

  3. History and Background- Frontier Geosciences Inc - • Bob Brunette • Hg Emissions Group Leader • Hg Analytical Lab Director • 10 Years Research Focus On Hg In Process Gas Emissions • Frontier Geosciences Inc • Originally an EPRI Contract Research Laboratory • Specialized Inorganic Research And Consulting • Co-authored US EPA 1631 = Total Hg • Co-Authored US EPA 324 and Authored FAMS Methods • Authored/Co-Authored US EPA 1600 Series Metals Methods

  4. Frontier Geosciences Authored/Co-Authored Methods • US EPA Method 1630: Determination of Methyl Mercury in Water and Tissues by Distillation, Extraction, Aqueous Phase Ethylation, Purge and Trap, Isothermal GC Separation, Cold Vapor Atomic Fluorescence Spectrometry. • US EPA Method 1631: Determination of Mercury in Water by Oxidation, Purge and Trap and Cold Vapor Atomic Fluorescence Spectrometry. • US EPA Method 1637: Determination of Trace Elements in Ambient Waters by Off-Line Chelation, Preconcentration and stabilized Temperature Graphite Furnace Atomic Absorption. • US EPA Method 1638: Determination of Trace Elements in Ambient Waters by Inductively Coupled Plasma-Mass Spectrometry. • US EPA Method 1639: Determination of Trace Elements in Ambient Waters by Stabilized Temperature Graphite Furnace Atomic Absorption. • US EPA Method 1640: Determination of Trace Elements in Ambient Waters by On-Line Chelation Preconcentration and Inductively Coupled Plasma-Mass Spectrometry. • US EPA Method 1669: Sampling Ambient Water for Trace Metals at EPA Water Quality Criteria Levels.

  5. Why Measure Hg At The Sub PPB Range?Historical Perspective – Hg In Waste Water Effluents

  6. How Accurate Is US Utility Hg Emission InventoryBased On Coal Hg Measurements? • 25 Year Record Of Coal Hg Based On ASTM 3684 • 1999 ICR Prescribed The Use Of ASTM 3684 Method • ASTM Method Has Shown High LOD/LOQ Relative To The Range Of Mercury Concentrations Found In Coal. • ASTM Method LOQ = ~ 0.06ppm • Range Of Coal Hg Concentrations: 0.02 – 0.18ppm

  7. Coal Mercury Measurements Variation Between Laboratories and Methods

  8. Benefit Of Low-Level Sensitive Analytical Methods “EPA is now aware of several studies in which the techniques employed in the above guidance (EPA-1631 CVAFS and other 1600 series methods) have been applied and have been of great benefit in determining that either an environment problem does not exist or that the magnitude of the problem is considerably less than initially envisioned. Therefore, the added costs associated with the sample handling and quality control protocols contained in the draft guidance are often trivial when compared to the cost saved by avoiding unnecessary pollution controls that might otherwise have been required.” • Source - U.S. EPA Fact Sheet – March 1996

  9. Hg Control Systems – Do They Work? • Evaluate Existing and Proposed Hg Controls • Measure Hg Concentrations Throughout Existing APCD • Direct Measurements For Each Application To Facility • Each System (Existing or Installed) Should Be Tested To Understand Optimal/Routine Efficiencies • Measure Total Hg and Hg Speciation • How Does Mercury Behave In This System? • Engineering Controls – Do The Results Make Sense? • Manufacture Specifications – Are They Achieved?

  10. Barrier To Evaluate Hg Control Systems -Diagnostic Tools Needed To Evaluate Control Systems • Existing Impinger Methods: (Ontario Hydro/101A/M29) • Difficult To Implement In Field • Expensive • Poor Field QA/QC • Few Data Points Generated For Effort/Cost ($10K/Sample for ~ 3-4 Runs) • Field and Analytical Methods Are Antiquated (CVAA) • High Detection Limit • EPRI/DOE Hg Measurement Workshop – retire OH? • Not Capable Of Continuous Emission Monitoring • Hg Continuous Mercury Monitors (CMM): • Alpha/Beta Development Stage • Having Difficulty Applied To Coal Fired Flue Gas • Expensive (Cost, O&M, Dedicated CEM Staff) • Smelter/Roaster Process Gas Too Complex – High Level Hg

  11. US EPA Method 324 and FAMSFully Validated Methods • US EPA PBMS Validation Study – 2000 • Validation Against Gold Standard – ASTM Ontario Hydro Method • US Dept Of Energy Validation Study – 2001 • Validation Against Gold Standard – ASTM Ontario Hydro Method • US EPA 301h Validation Study - 2004 • Validation Against Gold Standard – ASTM Ontario Hydro Method • US Dept Of Energy Validation Study – 2004 • US EPA 301h Validation – 2004 (FAMS Pending) • 40 CFR Part 75, Appendix K – March 2005

  12. US EPA Method 324- Trap View - Quality Control Hg(0) + Hg(II) PHg

  13. US EPA 324 – Short Term Sampling

  14. US EPA 324 – Spiked Trap

  15. US EPA Method 324- Principles Of Operation - • High Purity Solid Sorbent • Captures All Species Of Gas Phase Mercury FSTM = PHg (Semi-Iso) + Hg(0) + Hg(II) • Variable Flow Rate (0.10 – 4.0 slpm) • Fast (5-15L in 15-30 min) Total Mercury Determination • No Temperature Constraints (> dew point to 1000F) • Highly Standardized Blank (0.25ng Hg +/- 0.25ng) • Trap Hg Capacity - 5% (of the mass of the trap) Hg(0) = 7mg/trap Hg(II) = 1mg/trap (Or a 1 Hour Test @ 233,000 ug Hg/m^3)

  16. US EPA 324 Sampling Diagram

  17. US EPA 324 Probe Design

  18. US EPA Method 324 - Total Hg Sampling Options - • Short Term Sampling: • 6 mm - EPA 324 Trap • 15 minute to 24 hour Sampling • Continuous Emission Monitoring: • 10 mm – EPA 324 Trap • Continuous Integrated Sampling • 1 Day to 12 Day Sampling

  19. Flue Gas Adsorbent Mercury Speciation (FAMS) Sample Trap View

  20. US EPA 324 and FAMS Special Features • Fixed Probe – No traversing stack • Gas Phase Constituents Do not Behave Like Particles • Gas Phase Constituents Are Not Influenced By Gas Velocity • Traverse and Iso-Kinetics Designed For Capturing Particulate • Greater Than 95% Of Hg In Flue Gas Is Gas Phase • Total Hg – Keep Trap Above Dew Point • Speciated Hg – Keep Trap @ 95C +/- 5C • Maintain 0.25-0.50 Flow Rate

  21. US EPA 324 and FAMS Applications To Sources • Coal-Fired Utilities • Coal-Fired Boilers • Municipal Solid Waste Incinerators • Cement Kilns • Steel Mills • Smelter/Roasters • Landfill Gas • Oil/Gas Refineries • Mercury Retort

  22. Hg Emission Controls • Existing Hg Controls: Smelter/MSW Incinerator • Key To Hg Emission Control: Chemistry/Measurements • Coal-Fired Power Hg Emissions Control • Coal: Cleaning/Switching/Blending/Additives/Combustion • Co-Benefit APCD Mercury Removal • Enhancing Existing APCD Co-Benefit Hg Removal • Mercury-Specific Emission Controls • Activated Carbon Injection

  23. Existing Hg Controls: Zn Smelter Hg Control • Calomel Process: Hg Removal Tower HgCl2 + Hg(0) - > Hg2Cl2 • Inexpensive to operate • 40 foot Calomel Tower Lifetime = 10 yrs • 99% efficient at removing Hg

  24. Hg Tower / Polishing System

  25. Hg Removal Efficiency – Hg Tower and Polishing System

  26. Existing Mercury Controls Activated Carbon Injection – MW/MSW Hg Control • * Source – US EPA Web Site (www.epa.gov)

  27. Hg Control In Coal-Fired Flue Gas Hg Emission Controls Governed By: • Coal Plant Design • Existing Air Pollution Control Device • Source Type: Type Of Coal Combusted

  28. Hg Control: A Function Of Hg Chemistry • Particulate Bound Hg = PHg • < 5% Of Total Hg In Coal-Fired Flue Gas • Gaseous Oxidized Hg = Hg(II) • Water Soluble • Easily Removed By Existing FGD/SDA • Gaseous Elemental Hg = Hg(0) • Not Water Soluble • Requires Hg Removal System To Remove

  29. Coal Type: Hg Speciation and Concentration • East: Bituminous ~ 60% Gaseous Hg(II) [Water Soluble] ~ 30% Gaseous Hg(0) ~ 30% Higher Mercury Than Western Sub Bit/Lignite • West: Subbituminous or Lignite ~ 20-30% Gaseous Hg(II) [Water Soluble] ~ 70-80% Gaseous Hg(0)

  30. “Co-Benefit” Hg Removal • Existing APCD Not Designed For Hg Control • Selective Catalytic Reduction (SCR) = NOx Control < Shown To Convert Hg(0) to Hg(II) > • Flue Gas Desulfurization (FGD) = SOx Control < Removes Water Soluble Hg(II) > • ESP/Baghouse = Particulate Control < Removes Hg Bound To Fly Ash >

  31. Hg Removal From Existing Air Pollution Control Devices (APCD) ~ Ave = 35% DOE NETL - Feeley, et al

  32. Examining “Co-Benefit” Of Existing APCD – Via US EPA 324 and FAMS Methods Flue Gas Sample Location #1 Flue Gas Sample Location #2 Flue Gas Sample Location #3 Flue Gas Sample Location #4 Flue Gas Sample Location #5 Stack Pulverizer Boiler SCR Air Pre-heater ESP FGD Coal SBS • Fly Ash • B. Ash • Limestone • Gypsum • Supply H20 • Scrubber H20 • Scrubber Slurry

  33. “Co-Benefit” Examination: FAMS And US EPA 324 Total Hg Across SCR/ESP/FGD

  34. Co-Benefit Examination: FAMS Method Hg Speciation Across SCR/ESP/FGD FGD SCR/ ESP U2

  35. “Co-Benefit” ExaminationHg Removal Efficiency Assessment

  36. Coal and Coal Combustion Modifications • Coal Cleaning ~ 33% Removal Before Combustion (EPRI) • Coal Switching (Low Hg Coals) ~ 66% Reductions (EPRI) • Coal Blending ~ 80% Reductions (EPRI) • Produce Higher Water Soluble Hg(II) – Removal By FGD/SDA • Bit. and Subbit. Mix – High Unburned Carbon = ESP/BH/FGD • Combustion Operation Parameters ~ 50-80% (EPRI) • Burn Coal Less Efficient – Unburned Carbon Economic Viability Of These Solutions Difficult To Quantify Plant-By-Plant Evaluation

  37. Enhancing Existing APCD Co-Benefit Hg Reductions 25% Of Existing Coal-Fired Power Plants Have an FGD/SDA • Liquid Polymer Additive • Used Affectively For Hg Wastewater Removal • Oxidizes Elemental Hg And Retains – 1 step • Proof Of Concept: 15-25% Hg(0) Hg Removal • Application To Existing Wet Scrubber/FGD/ESP • No Additional Capital Equipment • Add Polymer To Reservoir/Add Water • Additionally Removes Suite Of Metals From Wastewater Down To 95% Reductions (As, Cd, Cr, Cu, Ni, Pb, Zn)

  38. Coal-Fired - Hg Specific ControlsActivated Carbon Injection • The Most Studied And Promising Technology • EPRI/DOE Funding and Research 2000-2007 • Phase I and II (Full Scale Evaluations 2003-2007) • Activated Carbons - • Chemically Impregnated Carbons • Brominated Carbon • Regenerable Sorbents (Nobel Metals) • Silica Based Chemically Based Sorbents

  39. Challenges Of Carbon Injection In Coal-Fired Flue Gas Activity Carbon Injection (ACI) • Large Mass Of Carbon Required To Adsorb Hg • Limited Hg Capacity (3%) • Low Mercury Capture Efficiency (contact time) • Limited Temperature Operation Range (> 75C) • Only Operates Well In Dry Gasses • Mixed Carbon/Fly Ash Can Not Be Used For Cement Generally Not Commercially Viable In Application To Most Coal-Fired Power Plants

  40. High Capital Equipment Expense Additional Capital Equipment - Retrofit DOE NETL - Feeley, et al

  41. Activated Carbon Injection – Lower Capital Equipment – Preserves Valuable Fly Ash Market DOE NETL - Feeley, et al

  42. Conclusions • US EPA 324 and FAMS – Accurate, Inexpensive, Precision, High Data Generation Method • Family Of Activated Carbons: • Most Promising Technique To Date (Coal-Fired) • Phase II – Long Term Tests To Aid In Longevity of Sorbents • Most Promising Sorbent (Halogenated/Silica Based Sorbents) • Low Cost/Low Impact Injection System Preserves Fly Ash • Baseline Cost: $50K-$70K/lb Hg Removal • Goal To Reduce Cost By 25-50% Through 2010

  43. Conclusions (Cont’d) • Most Emissions Sources Don’t Know Their Source Hg Concentrations or Emissions With Confidence • Recommend Hg Baseline Study Prior Hg Control Decisions • “Co-Benefit” Hg Removal From Existing APCD • Average Hg Removal Is 30% Across Industry • Recent Tests: SCR/ESP/FGD Removes 85% • Other Industry Specific Show 99% Hg Removal • Hg Specific Controls Are In Phase II Assessment • “Long Term Effectiveness Of Controls Uncertain • Economy Of Hg Specific Controls Uncertain • Phase III Testing DOE/EPRI/EPA 2005-2010

  44. Hg Monitoring And Monitoring WESTAR Fall Meeting Mercury and Air Quality – Sources, Effects, and Controls San Diego, California September 22, 2005 Bob Brunette Frontier Geosciences Inc 414 Pontius Avenue North Seattle, Washington 98109 Bobb@frontiergeosciences.com 206 957 1461

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