Presentation Overview Air Quality Regulations Evolution in the U.S. Summary of Current NESHAPS Regulations Mercury Emissions Control and Measurement T

Transcription

1 A Review of the Evolution, Status and Compliance Initiatives Associated with Process Mercury Emissions Monitoring Standards in the United States CEM 2014 International Conference and Exhibition On Emissions Monitoring 14th - 16th May 2014 Istanbul, Turkey by Karl R. Wilber, PE Tekran Instruments Corporation 230 Tech Center Drive Knoxville, TN kwilber@tekran.com

2 Presentation Overview Air Quality Regulations Evolution in the U.S. Summary of Current NESHAPS Regulations Mercury Emissions Control and Measurement Traceability Protocol Example Data Status and Outlook 2

3 U.S. - Clean Air Act 1970 Establishes EPA in December 1970 Air Program called Air Pollution Control Office o Included Office of Air Quality Planning and Standards (still called that today) o As name implies, focus was on development and regulation of control technologies o Included Emissions Measurement Branch R&D program called Research and Monitoring o Branch for test methods research about 10 people 3

4 Some EPA History Established in 1970 with Clean Air Act New Source Performance Standards (NSPS) for Power, Cement Process, etc. New EPA Test Methods o Methods 1-4 (traverses, flow, moisture, MW) o Method 5 (dry PM) o Methods 6, 7, and 8 (SO2, NOx, and H2SO4) o Method 9 (visible emissions, opacity) Only 20 Pages in the Federal Register! 4

5 1990 Clean Air Act Amendments Expanded list of National Emissions Standards for Hazardous Air Pollutants (NESHAPS) from seven (7) to 187! NESHAPS requires Maximum Achievable Control Technology (MACT) Added New Source Performance Standards (NSPS) for new, modified or reconstructed facilities In many cases requires Continuous Emissions Monitoring Systems (CEMS) For each CEM System there is Performance Specification 5

6 2011 Federal Register Notices Mercury and Air Toxics and New Source Performance Standards Electric utility (MATS) and boilers and incinerators NSPS Pollutants o NSPS - SO2, NOx, PM filter o MATS HCl, HF, and Hg o Alternative limits PM, nonhg HAP metals, SO2 Testing and monitoring appendices o Hg CEMS and sorbent trap CMS o HCl and HF CEMS 211 pages o FR notice - 3 column Table of Contents o MATS rule 2 column Table of Contents 6

7 Regulatory and Legal Evolution 1971 NSPS rationale in <1 FR page Administrator s judgment that o Control technologies are available o Control costs are reasonable o 50 page technical information document 2011 MATS rule >150 FR pages to address o Multiple CAA, APA, and FR requirements o >12 separate Acts and EOs o 510 page Regulatory Impact Analysis for MATS o 196 page Hg Risk Assessment 7

8 Drivers for NESHAPS Public Heath $37 90 Billion U.S./year 8

9 In General U.S. emissions limits are established with same methods used for compliance New or different applications of test methods are proposed with applicable rules for comments Federal rules specify compliance test methods o Run duration, process conditions o Operational criteria (e.g., temperature) o Acceptable alternatives 9

10 In the USA, HgCEM Equipment Trials in Real Flue Gas Determines Acceptance There is no equivalent MCERTS or TUV certification process required in the USA for HgCEM equipment. Instead there were: o EPA Field Trials in o Independent Research Group Performance Testing (e.g. EERC) o Field Trials by Power and Cement Companies o Frequent Relative Accuracy Tests Audits (RATA) 10

11 U.S. EPA EGU MATS and Cement MACT Summary [Hg] must be really low ~ 1.5 ug/m 3 for EGUs EPA Electric Generating Unit Mercury and Air Toxic Standards (MATS) promulgated January 2012 The EPA Portland Cement MACT Targeted MACT Pollutants and limits Targeted MATS Pollutants and limits Deadline for Compliance April, 2015 Deadline for Compliance September,

12 Impact of Regulations New Air Pollution Control Strategies New or Improved Monitoring Technologies Proof of Performance of 1 & 2 Compliance Monitoring and Reporting Control Systems Performance Monitoring and Optimization Plant Retirements 12

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14 Example: Mercury Abatement Annual Cost Sorbent Injection 500 MWe Coal-fired Plant Mercury Removal Costs Hg Re emoval Efficii iency 100% 80% 60% 40% 20% 0% Efficiency ug/m3 $1000 The last 15% removal may cost an additional 50%. ($ 1 million/year! ) Low-level measurement accuracy more important than ever! 14

15 Why do plants use Activated Carbon Injection, Bromine, etc.? ACI captures Hg 0, Bromine helps oxidize Hg making it easier to capture on PM or in a scrubber 15

16 Accurately Measuring pptv - Levels of Mercury in Flue Gas 1 µg/m 3 Hg = 112 parts per trillion (v/v) Many potential interferences and losses. Tekran R&D spent 1998 to 2003 understanding flue gas mercury reactions in the laboratory and we re still learning Mercury appears in different species o Elemental - Hg 0 o Ionic - Hg Hg 2+ o Particulate-bound - Hg P Detectors can only measure Hg 0 16

17 EERC Study Low-Level Level Measurements (funded by EPRI, ICCI, CATM) 17

18 Oxidized mercury conversion and interference prevention: The Tekran approach (pat d) Task: quantitatively convert all Hg 2+ to Hg 0 with no back reactions in the presence of high concentration redox compounds and reactive surfaces Proprietary thermal converter material set at 700C DI water mist injected into tail of thermal converter to fix Hg 0 from potential back reactions and eliminate interferences Gas is rapidly chilled, water condenses carrying away reactive compounds, and Hg 0 in a clean gas matrix goes to the analyzer 18

19 New 3300xi HgCEMS Same trusted components with improved physical design 3300 HgCEM 3300Xi HgCEM S 2537Xi+ Analyzer System controller Xi Hg 0 Calibrator 3321 Conditioner Controller Oxidizer Option 19

20 Tekran New Generation HgCEM System 3321 Sample Conditioner and Control Unit Converter Conditioner Components Modular Power Panel Modular Umbilical Heaters Probe Control Hardware Modular Electronics HgCl 2 Generator Oxidizer Type Optional Wall-mounted - cabinet closed 20

21 HgCEMS Evolution Example of Challenges Heated Umbilicals (a) Tekran and Major Umbilical Supplier combined forces on 26 modifications to the early heated lines (>$2M invested) 21

22 Cabinet-Based Tekran 3300Xi HgCEMS Interior 3300Xi HgCEMS Cabinet Cabinet for HgCEMS 22

23 Tekran 3300Xi Dual Port Sampling Applications: Mercury control technology o Research and development o Acceptance testing at new installations o Optimization and performance monitoring Regulatory monitoring of multiple, close-proximity emissions stacks. 23

24 Method 30B This method is only intended for use only under relatively low particulate conditions (e.g., sampling after all pollution control devices) This method is designed to measure the mass concentration of total vapor phase Hg in flue gas, including elemental Hg (Hg 0 ) and oxidized forms of Hg (Hg 2+ ), in micrograms per dry standard cubic meters (µg/dscm) Sorbent Traps have: o mineral wool section (intended for PM), o primary capture section, o secondary (breakthrough) capture section o final mineral wool section Hg P that is captured in the trap is included in the analysis 24

25 EPA Schematic of Basic Dual Sorbent Trap Sampling System 25

26 The Electronic HgCEMS vs. Sorbent Trap Feature Electronic HgCEMS Sorbent Trap Capital Cost (including installation) 2+ times higher than Sorbent Trap $75-$100K Operations and Maintenance Lower than Sorbent Trap -Requires routine retrieval and Costs analyses of traps (see next slide) -Traps are consumables Training and Complexity Real-time feedback for Process and APCD Higher Level Training more complex Valuable for real-time assessments and process feedback and control -Comparatively simple to operate - No capability for real-time feedback - data only available after days of exposure and analytical processing delays 26

27 The Electronic HgCEMS vs. Sorbent Trap Total Cost of Ownership HgCEMS 27

28 NIST Traceability Protocol Elemental Hg generators used vs. Hg cylinder gas. NIST Traceability involves unbroken chain of calibrators and ongoing adherence to U.S. EPA traceability protocol. EGU s typically 0-10 µg/m 3 Portland Cement - two levels o Mill On e.g. (0-30 µg/m 3 ) o Mill Off e.g. (0 300 µg/m 3 ) Corrections Required in Emissions if Calibration Fails 28

29 NIST Traceability Protocol for Hg Generators Unbroken Chain of Comparisons 1 NIST Prime Vendor Prime Field Reference Generator User or Field Generator 1 Slide courtesy of Jeff Ryan, U.S. EPA Clean Air Markets 29

30 NIST Hg Generator Calibration Levels (as received from NIST Dec. 2013) National Institute of Standards and Technology (NIST) Mercury Generator Calibration Points Low-Level (µg/m3) High-Level (µg/m3) Typical Levels of Interest for EGU MATS and many Mill-On PC MACT Conditions Likely levels for Portland Cement Mill- Down Conditions 30

31 Where Are We Now in the U.S.? New parameters to be measured including PM, Hg, HCl, THC Low-level measurements and Reference Methods challenges Compliance deadlines in 2015! 31

32 Broader Landscape U.S. Landscape o Coal-Fired Power - more pollution control and monitoring systems. Some plants retiring. o Cement Plants on similar timeline but few retiring. o Open items relative to compliance o Resources required to support compliance? o Low- level accuracies and RATA testing? o Ability to consistently achieve ongoing compliance? International Landscape o Regions adding more pollution control and monitoring equipment o Changing Energy Sources -conversion to renewables and natural gas o Some regions assessing U.S. initiatives to evaluate lessons learned 32