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MKS Instruments On-Line Product Group 2 Tech Drive, Suite 201 Andover, MA 01810 Tel: 978-482-5364

Ultra Low Level HCl CEMs for Coal Combustion Facilities Using FTIR and Associated Performance Specifications. California Desert Air Working Group CDAWG November 13-14, 2013 Las Vegas, NV. Peter G. Zemek. MKS Instruments On-Line Product Group

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MKS Instruments On-Line Product Group 2 Tech Drive, Suite 201 Andover, MA 01810 Tel: 978-482-5364

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  1. Ultra Low Level HCl CEMs for Coal Combustion Facilities Using FTIR and Associated Performance Specifications California Desert Air Working Group CDAWG November 13-14, 2013 Las Vegas, NV Peter G. Zemek MKS Instruments On-Line Product Group 2 Tech Drive, Suite 201Andover, MA 01810Tel: 978-482-5364 MultiGas™ FT-IR Automated HCl CEM Systems

  2. Discussion • 40 CFR Parts 60 and 63 - (NESHAP) for the Portland Cement Manufacturing Industry and Standards of Performance for Portland Cement Plants - Meet Standard by 2015 • EPA Utility MACT (40 CFR Part60, Subpart UUUUU, EPA – 1,350 Units Affected • Continuous Monitoring (HCl) from new and existing coal and oil-fired (HF) emissions • Cement - 3 ppmv HCl, (3.8 mg/M3 @ 7% O2), EGU – 1 ppmv HCl • Instrument HCl Quantification - Rule of Thumb 20% below Emissions Regulation, So need 0.2 ppm Current MKS FTIR is 50 ppb • Use Performance Specification 15, App B and Procedure 1 of Appendix F until new PS (20 yrs. old) • New PS-18 in development specific to HCl (Spring 2014) • Initial Instrument Qualification • On-going QC promulgated separately

  3. Performance Specifications for FTIR CEMS • PS-15 For Extractive FTIR CEM Systems in Stationary Sources • Reference Method RATA Run Comparisons – Follow PS 2 Specifications and Test Procedures for SO2 and NOX CEM in Stationary Sources – WILL BE CHANGED (M320/ASTM D6348-12) • Draft PS-18 and Test Procedures for HClCEMS in Stationary Sources - Spring 2014 • Tests on-going at EPA RTP-NC • NIST traceable standards now available 1-20 ppmv Bal N2. EPA has a 1 ppm NIST traceable standard. We match against HITRAN - High Resolution Transmission -Air Force Research Laboratories (1960s) Harvard-Smithsonian Center for Astrophysics, Cambridge MA, USA. Worldwide standard of atmospheric molecular transmission and region of the EM spectrum

  4. FTIR Reference Methods for CEMS Validation and RATA • Reference Methods: • Method 301—Field Validation of Pollutant Measurement Methods From Various Waste Media • Method 320* - Measurement of Vapor Phase Organic and Inorganic Emissions by Extractive (FTIR) (Includes FTIR Protocol) • Method 321** - Measurement of Gaseous HCl Emissions at Portland Cement Kilns by FTIR Spectroscopy • ASTM D6348-12 Standard Test Method for Determination of Gaseous Compounds by Extractive Direct Interface Fourier Transform Infrared (FTIR) Spectroscopy *1 of 2 RM for EGU **Only acceptable RM for Portland Cement MACT

  5. PS18 CEM Installation Validation Tests • By MANUFACTURER/Integrator in LAB • Interference Test (Use list in PS18) • Limit of Detection (LOD) Determination • Calibration Error (CE) Test • IN FIELD • Response Time Test • Seven Day Calibration Drift Test • Stratification Test • Relative Accuracy Test or Dynamic Spiking Test

  6. Validation and On-Going HCl CEM PS-18 • Before Installation, instrument manufacturer must perform: • Linearity (Cal Error) 5%, Intercept must be <15% of Span • Detection Limit (LOD) 2-5x est. LOD, then 3 x StdDev 7 (any) rdgs. • Cross Sensitivity (Interference) <3% Total of Cal Span • After Installation to Validate must perform: • (Relative Accuracy Test) RATA Spikes SR >20%, RA >15% • Reference Method Test HCl - EPA-M321 RATA • Includes Dynamic Spike, • 7 day drift test • Response Time Test (t90 Up and Down) (<15 min) • Daily and On-Going (all automated) (Expected) • Zero • Dynamic Spike or Dry Cal Span (Wet or Dry) • Periodic RATA (Relative Accuracy Test) • Provide 30 day rolling avgHCl

  7. Advantages of FTIR • Measurements done Hot-Wet • Required for polar components HCl, HF • Works with High CO2 and H2O • No Chemical Conversions • Multiple components Simultaneously • THCs, HCl, HF, VOCs, NOx, SO2, etc. • Additional components: • No hardware change • Can be added in the field • Simple Operation • No daily maintenance • No Daily Calibration • High sensitivity gas cell • small volume (200mL) • long path length (5.11m) • No training needed • Software alerts to any malfunction • Only laser replace and cell cleaning • Fast (1 Hz or 5 Hz) Hz = per Second

  8. Whatis FTIR? • Fourier Transform Infrared Spectroscopy (Spectrometry) • Fourier Transform: mathematical conversion from the time domain to the frequency domain • Infrared: Low energy wavelengths longer than visible light (heat) • Spectroscopy: study of the electromagnetic spectrums electrical and magnetic fields • FTIR uses an “Interferometer” -- a device which splits focused light, optically retards it and recombines it to produce an optical interference pattern resulting in anInterferogram. • A computer converts the Interferogram to an Absorbance spectrum which is Linear

  9. MKS IR Spectroscopy Hardware • Source: Blackbody (Hot Silicon Carbide ~ 1300 K) • Modulator: Interferometer • Sample: Vapor (Gas Cell- 10m, 5.11m, 35cm, or 2cm path lengths) • Detector: Mercury Cadmium Telluride (MCT) Quantum Detector cooled by Thermoelectrically (TE) Peltier • NOT DTGS Photo-detector - Not sensitive enough

  10. Fourier Transform Infrared (FTIR) 2 1 Water H2O 3 1Symmetric 2Symmetric 3Asymmetric

  11. The FT-IR Light Modulator Creating the Interferogram HeNe Laser monochromatic light Fixed Mirror Beamsplitter Moving Mirror IR Source To Gas Cell & Detector

  12. Interferometer For one wavelength, where B(n) = Intensity at wavenumber n (n=1/l in cm) and I(d) = the corresponding interferogram For many wavelengths, one can extend I(d) as an interferogram and the original spectrum is then the Fourier transform of the interferogram. A is a constant of the integration.

  13. FTIR From Igram to Spectrum • Create Interferogram then send to detector (Modulator) • Amplify Interferogram (preamp) then digitize it (A/D converter) • Send digital signal to computer (PC) • Apply Fourier Transform math to Interferogram, result is Spectrum (I) • Remove background noise signals (Io) from Sample (I) • Result is Absorbance gas spectrum (A) used to identify the different species

  14. Background and Sample BACKGROUND (Io) N2 Purge SAMPLE (I) 1000 ppm NH3 Absorbance = - Log (I/Io)

  15. Absorbance is Proportional to Concentration Absorbance = - Log (I/Io) Absorbance =  • C • path FFT of Sample 1000 ppm NH3

  16. FTIR Analysis Method • Analytical Method • Classical Least Squares (CLS) then Beers Law, Abs = a b c  measured spectrum a absorptivity coefficient or ε  from calibration b path length  fixed (5.11 meter) c sample concentration (calculated) what we want • Canned Method - No user input necessary • Hot and Wet, No sample change – No ionization • No pressure drop across sample cell • 1 scan/second - 1 data point every 30 seconds • 40 sample cell turnovers per minute • Self -validating sample method • Cement – Only acceptable reference method EPA M321

  17. 1 2 a+b a ABSORBANCE b WAVELENGTH Classical Least Squares Model • Based on Beer’s Law • Relatively fast computationally • More complex mixtures • Wavelengths used need to be greater than #components • Noise reduced as #s increase CLS Spectral Analysis  Finds factors for all reference spectra in method/recipe to recreate the sample spectrum

  18. Powerful Technique - CLS for HCl Measurements with FTIR Sample (white) with 5 ppm HCl and 12% water (red) H2O subtraction HCl peaks clearly visible after H2O subtraction

  19. Powerful Technique - CLS for HCl Measurements with FTIR HCl calibration peaks (red and green) HCl subtraction After HCl subtraction, only noise left

  20. Examples of Pre-Abatement Coal Fired (Cement Plant) Gas Concentrations Measured by FTIR * Also includes periodic high concentration spikes • All values in ppmv (or ppm) • Includes data from non-US plants • Concentration ranges e.g. min reading. Note: max reading, not rolling averages • Data spanning few minutes to few days • H2O and CO2 also measured with targets (cost effective) • * - Not measured with high sensitivity instrument (but can do high levels)

  21. Raw Mill ON Raw Mill OFF HCl Concentration (ppm) Examples of HCl Concentration Profiles at Cement Plants – RM On/Off Time 22

  22. TÜV ranges & uncertainties MKS 2030D TE9 CEM FTIR 1 ppm HCl = 1.49 mg/m3

  23. FTIR Suppliers - TÜV Ranges & Uncertainties

  24. EPA Test Facility – PS18 RTP, NCMKS Reference Method -Anchor • ORD’s Multi-Pollutant Combustion Research Facility • 4M Btu/h down-fired combustor firing coal and/or NG • Multiple pollution control configurations possible • SCR, ESP, FF, Wet Scrubber • Duct injection of gases to control emission profiles and combinations • HCl, SO2, NOx, CH4, CO, NH3, H2O, CH2O • All CEMS and RM measurements from same basic location

  25. EPA REFERENCE METHODS – MKS FTIRs - Anchors for Testing (EPA and Industry) • Looking at 3 different high resolution FTIR analyzers • Focus on DLs, measurement quality and RM performance at very low HCl levels LN2, TE9, HS • Point of reference for HCl Gas Standards

  26. NEW: High-Sensitivity FTIR HCl Analyzer for CEM • HCl detection limit 0.03 ppm (30 ppbv) plus bias • Hot and Wet – 200mL Sample Volume • No liquid nitrogen (LN2) needed • No N2 Background → easier integration than standard FTIR – turn on and go • No Calibration Needed– “Canned” Method • Can measure HCl, CH2O, HF, H2O, N2O, CH4 with similar high sensitivity – or ELIMINATE Spectral Regions of no concern –hardware based

  27. Installations -Two CEM systems two Cement Plants –Passed PS18 RATA 1 is almost 1 year old and 2 other HCl CEM going in -Two in Hildago, Mex. CEM PS-15 Cal Data 2 years Running

  28. Transferrable Hardware & Software

  29. Detector/Hardware InfluencesHigh Sensitivity System HCl, HF, CH4, H2O, N2O, CH2O Sensitivity (signal) TE9u CEM LN2-16u MCT (77K) TE-HS CEM >S/N IR Band-pass Filters <noise spectral region

  30. EXAMPLE of No Cross Sensitivity No change in HCl concentration Spike @ 900 ppm CH4 and 6% H2O

  31. Staged Blowback Filtration 80 psig

  32. MKS FTIR CEM Data 15 Days • RM and PS18 require a Dynamic Spike • Replace 10% CEM flow with spike material • Spike10 x 50% of what’s found (3 ppm native, 15 ppm spike) • Result Theoretical ~3+1.5 = 4.5 ppm HCl CEM • Recovery +-20%, RM is 30%

  33. H2O vs. HCl in CEM Cement Extractive System No Filter Change or Blowback – 4 months CEM passes PS-15/Draft 18 with Sig Filter Cake, until Dry Gas is introduced Dropping H2O to < 0.5%, Filter cake sublimes to HCl gas, Conc. Inc. rapidly Then, comes back to Steady-State when H2O > 0.5%

  34. HCl CEM Dynamic Spiking

  35. Which LOD/LOQ/MAU/MDC? • ASTM D6348-98/03 LOD – Measure of Precision • EPA Method 320 – Max Anal Uncertainty (MAU) MDC =2 stdev at 95% CI from Residual • NIOSH 3800 Method 1 - LOD (ambient) Examines Interference Residuals

  36. Detection Limits - Which One? 1 set of data

  37. Compliance SoftwareMDC/LOD/MAU/OFC EPA-M320,ASTM D6348-12

  38. Manual CheckTE-HS LODSoftware Included Goodness of Fit-2x sigma CH4 12 ppm HCl 30 ppb

  39. Comparison of HCl CalibrationsPrecision

  40. Comparison of MKS FTIR Analyzers Solutions for HCl * Detection Limit based upon 3σ in 30% H2O and 25% CO

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