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Robin Mills Ridgway, PhD. P.E.

Mercury Emissions Rules Overview of Hoosier Environmental Council’s Petition and EPA’s Utility Mercury Rule. Robin Mills Ridgway, PhD. P.E. Purdue University Physical Facilities Environmental Regulatory Consultant rmridgway@purdue.edu. Overview. Rule language and motivation

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Robin Mills Ridgway, PhD. P.E.

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  1. Mercury Emissions RulesOverview of Hoosier Environmental Council’s Petition and EPA’s Utility Mercury Rule Robin Mills Ridgway, PhD. P.E. Purdue University Physical Facilities Environmental Regulatory Consultant rmridgway@purdue.edu

  2. Overview • Rule language and motivation • What is known about mercury and chlorine in coals nationally • What is known about mercury and chlorine in Indiana coals • The problem of variability • EPA’s mercury rule • Summary

  3. Coal’s Role in Energy Production From ABEC (http://www.balancedenergy.org/state/in.asp)

  4. Motivation: • HEC’s proposed mercury rule language includes Purdue (recent word from IDEM indicates that the petition’s scope may have changed) • “Coal Fired Electric Utility”: Title V permit, generate electricity, >10% heat input from coal • 0.6 lb/TBtu or 90% reduction by 2008 • Compliance demonstrated with mercury CEMS (continuous emission monitoring system) • In addition, Purdue’s boilers are subject to “Boiler MACT” containing a mercury limit of 9 lb/TBtu • Purdue University burns Indiana coal. • First homework assignment on the path to Boiler MACT compliance by September 2007: understand our fuel

  5. Coal in the Wild #1:Coal deposited in a stream system; note trees for scale Courtesy K.D. Ridgway, Purdue University

  6. Coal in the Wild #2:Coal deposited in a stream environment; person for scale Courtesy K.D. Ridgway, Purdue University

  7. Mercury in Coal • Where in coal does mercury occur?The primary association is in pyrite, as indicated by indirect leaching studies, direct determinations by microanalysis, and limited XAFS data. • What other forms can be present?Include an organic association, and in some unusually mercury-rich coals, HgSe (tiemannnite), HgS (cinnabar), and even native mercury. Slide courtesy Allan Kolker, USGS

  8. NEXT:Several very distilled, simplified, summarized, organized depictions of the mercury (and other stuff) content of coals in the US probably prepared by a control-freak engineer like me

  9. But First: A Primer on Units of Measurement • “ppm”: • “parts per million”; • one part per million parts, • a very dry martini -1 drop of vermouth per 16 gallons of gin • “lb/TBtu” or “lb Hg/1012 btu”: • lb Hg/1012 btu = lb Hg/1,000,000,000,000 btu • Pounds per trillion Btu • One pound of coal has approximately 11,000 Btu; 2000 lbs of coal per ton • HEC’s proposed 0.6 lbs/TBtu is 0.6 lb per 46,000 tons of coal • Therefore: 0.6 lb Hg/TBtu ≈ 0.0066 ppm Hg in the coal

  10. Courtesy Allan Kolker, USGS COALQUAL mercury loadings for selected U.S. coal regions. Mercury and Btu/lb calculated to as-received (moisture containing) basis.

  11. USGS COALQUAL DATA(mean = 0.17 ppm; median = 0.11; standard deviation = 0.17) n = 7,430 [One outlier is removed] Slide courtesy Allan Kolker, USGS

  12. Take home message: • Mean of 0.17 ppm is 26 times the limit proposed by HEC • Therefore a source burning “mean”, or average, quality coal would have to reduce mercury emissions by 96% to meet 0.6 lb/TBtu

  13. Comparison of Average Mercury Concentrations in Coal (courtesy EERC) 0.14 14 0.12 12 0.1 10 0.08 8 Mercury, ppm Mercury, lb/TBtu 0.06 6 0.04 4 Hg, ppm 0.02 2 Limit proposed by HEC Hg, lb/Tbtu 0 0 App Int Bit. West. W. Sub. FU Lig. Gulf Bit. Bit. Lig.

  14. 35,000 1600 Ca, ppm 1400 30,000 Fe, ppm 1200 25,000 Cl, ppm 1000 20,000 Ca and Fe, ppm, dry Cl, ppm, dry 800 15,000 600 10,000 400 5000 200 0 0 App. Int. Bit. West. W. FU Lig. Gulf Bit. Bit. Sub. Lig. Comparison of Average Coal Characteristics (slide courtesy EERC)

  15. Mercury Variability in Coal Beds • Mercury content of coals can vary by coal basin, by rank, and within individual beds. • Within coal beds, zones that greatly exceed mean values tend to be localized. • Distribution of mercury reflects geologic processes, such as fluid migration, that operate on various scales, and can occur in the peat stage, during coalification, and/or post-date coal formation. Slide courtesy Allan Kolker, USGS

  16. Mercury Levels in U.S. Coals (courtesy EERC) HEC’s 0.6 lb/TBtu Take home messages: 1. ICR data represents only a subset of all coal 2. Note variability How to read the box plot J.C. Quick, T.C. Brill, and D.E. Tabet, Mercury in US coals: observations using COALQUAL and ICR data, Environmental Geology (2003) 43:247-259.

  17. Comparison ofUSGS and EPA ICR Data Sets • EPA ICR database reflects mercury content of commercial coals delivered in 1999 to U.S. power plants  25 MW. • USGS database includes data for about 40 elements and many coal-use parameters. • Subsets1 give averages of 0.10 ppm for ICR and 0.17 ppm for COALQUAL. 1 Quick et al. , 2003,Environmental Geology Slide courtesy Allan Kolker, USGS

  18. So, what about Mercury in Indiana Coal? M. Mastalerz, et al., 2004

  19. Mercury in Indiana Coal vs. US Total HEC’s proposed limit= 0.0066 ppm thus requiring 94% reduction for sources burning Indiana coal M. Mastalerz, et al., 2004

  20. Chlorine Content of Indiana Coals M. Mastalerz, et al., 2004

  21. Chlorine in Indiana Coal vs. US Total M. Mastalerz, et al., 2004

  22. HEC’s proposal Indiana Average

  23. Summary (for geologists)- Mercury in Coal • Mercury content of coal varies by coal basin, by rank, and within individual coal beds. Variation is a consequence of geologic processes. • Pyrite (FeS2) is the primary host for mercury in bituminous coals. An organic association is common in some low-rank coals. • Averages: 0.17 ppm Hg for in-ground coals (USGS COALQUAL database); 0.10 ppm Hg for coals delivered to U.S. coal-fired power stations. • Mercury loading is a function of mercury content and calorific value. Coals should be compared on a common energy-equivalent basis. Slide courtesy Allan Kolker, USGS

  24. Summary (for the rest of us): Mercury in Coal • Why not buy coal with low mercury content? • Coal-fired units are designed based upon specific fuel characteristics, therefore switching coal types is not an option • Mercury content is not the only variable in choosing a fuel: cost, availability, sulfur, and heating value are key. • Fuel variability must be taken into account when considering regulatory schemes. • Wide margins of error must be built into pollution control designs.

  25. What About EPA’s Mercury Rule? The Clean Air Mercury Rule (“CAMR”)

  26. Timeline to Federal Mercury Regulation • 1998 – EPA issued Information Collection Request (ICR) to utilities • 1999 – Data collection for ICR • EPRI later developed Hg emission prediction correlations from 88 units tested and coal samples taken from all units • 2000 – EPA decides to regulate utilities under MACT • 2002 – Utility MACT working group met 14 times from August 2001 to March 2003 • 2003 – EPA proposed draft rule issued on December 15 • 2005 – EPA to issues final rule mid March • 2010 – Mercury compliance begins for utilities

  27. Final CAMR Overview • Establishes cap-and-trade program under CAA §111 for new and existing sources • Cap of 38 tons/year in 2010 and cap of 15 tons/year in 2018 • EPA justifies phase 2 due to new sources having control requirements and push for new technology, with U.S. role as world leader • Unlimited banking allowed • New sources are subject to cap-and-trade rule

  28. CAMR Overview (continued) • Establishes “standards of performance”: • New units: emission rate standard • Existing units: cap-and-trade program • Builds on CAIR to allow power industry to address Hg, SO2 and NOx in coordinated effort • EPA projects annual costs to the power industry of $160 million in 2010, $100 million in 2015, and $750 million in 2020 ($1999) • EPA projects annual benefits of approximately $0.2 million to $3 million through 2020 ($1999)

  29. CAMR Timeline • October 31, 2006: initial state allocation decisions to EPA • November 17, 2006: state programs due to EPA • January 1, 2009: emissions monitoring/reporting begins (plants in operation before July 1, 2008) • January 1, 2010: Phase 1 cap-and-trade program begins • January 1, 2018: Phase 2 cap-and-trade program begins

  30. Mercury Rule Compliance: Issues to Consider • Whether Boiler MACT, Indiana Mercury Rule (HEC petition), and/or CAMR, issues are the same: • Coal properties (e.g., chlorine content) impact potential Hg capture performance • Significant variability in baseline Hg capture of existing pollution controls has been observed • The mercury capture “darling”: Activated Carbon Injection effectiveness depends on coal type and plant configuration • More long-term evaluation of ACI is necessary to determine realistic cost and performance estimates for various plant arrangements

  31. Mercury Rule Compliance: Issues to Consider (continued) • Uncertainties remain regarding capture effectiveness with various coal ranks and existing pollution control configurations, balance-of-plant impacts, and byproduct use and disposal • Baseline Hg capture performance for lignite and PRB coal-fired plants with ESP or SDA/FF is relatively low and untreated ACI performance is limited • Hg capture may be enhanced through addition of halogens via coal blending, coal additives, or use of chemically-treated activated carbon

  32. …and just when you think the rules are final and you can get on with compliance… here come the lawyers…

  33. The CAMR Litigation Landscape: • Numerous challenges to both §112 Revision decision and CAMR • Several environmental groups requested a stay on §112 Revision decision – denied by Court • 14 States have sought review of §112 Revision decision in D.C. Circuit • 14 States have challenged CAMR • 6 states filed in support of EPA • Court decision(s) likely in late 2006 or early 2007

  34. Summary • Various layers of regulations to consider: • For utilities, CAMR and Indiana Mercury Rule • For non-Utilities, Boiler MACT and Indiana Mercury Rule • Complex issues regarding fuel characteristics and control technologies • Potential impacts on mining and reclamation cannot be discounted

  35. Many Thanks to: • Allan Kolker, U.S. Geological Survey, Eastern Energy Resources Team, Reston, VA 20192 • Energy and Environmental Research Center (EERC); http://www.eerc.und.nodak.edu/ • Maria Mastalerz (Indiana Geologic Survey), A. Drobniak, G. Filipelli: “Distribution of Mercury in Indiana Coals and Implications for Mining and Combustion, Final Report to the Indiana Department of Commerce, July, 2004 (http://igs.indiana.edu/) • Dr. Kenneth D. Ridgway, Purdue University Department of Earth and Atmospheric Sciences • Gary Spitznogle, AEP, Advanced Technology and Control

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