FTIR CEM Performance Specification Modification Considerations

Transcription

1 FTIR CEM Performance Specification Modification Considerations EPA/ICAC Emissions Measurements Roundtable Meeting September 17, 2013 Peter G. Zemek MKS Instruments Marty Spartz Prism Analytical MultiGas FT-IR Technologies Automated HCl CEM Systems MKS Instruments On-Line Product Group 2 Tech Drive, Suite 201 Andover, MA Tel:

2 Performance Specifications for FTIR CEMS PERFORMANCE SPECIFICATIONS: PERFORMANCE SPECIFICATION 15 - FOR EXTRACTIVE FTIR CONTINUOUS EMISSIONS MONITOR SYSTEMS IN STATIONARY SOURCES RM RATA RUN COMPARISONS FOLLOW PERFORMANCE SPECIFICATION 2 SPECIFICATIONS AND TEST PROCEDURES FOR SO2 AND NOX CONTINUOUS EMISSION MONITORING SYSTEMS IN STATIONARY SOURCES DRAFT PERFORMANCE SPECIFICATION 18 AND TEST PROCEDURES FOR HCL CONTINUOUS EMISSION MONITORING SYSTEMS IN STATIONARY SOURCES

3 FTIR Reference Methods for CEMS REFERENCE METHODS: TO VALIDATE UPON INSTALLATION OR RATA METHOD 301 FIELD VALIDATION OF POLLUTANT MEASUREMENT METHODS FROM VARIOUS WASTE MEDIA METHOD 320* - MEASUREMENT OF VAPOR PHASE ORGANIC AND INORGANIC EMISSIONS BY EXTRACTIVE FOURIER TRANSFORM INFRARED (FTIR) SPECTROSCOPY (INCLUDES FTIR PROTOCOL) METHOD 321** - MEASUREMENT OF GASEOUS HYDROGEN CHLORIDE EMISSIONS AT PORTLAND CEMENT KILNS BY FOURIER TRANSFORM INFRARED (FTIR) SPECTROSCOPY METHOD EXTRACTIVE FTIR METHOD FOR THE MEASUREMENT OF EMISSIONS FROM THE MINERAL WOOL AND WOOL FIBERGLASS INDUSTRIES ASTM D 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

4 Confusion and Errors Between Methods/Specifications? TEST METHOD MEASUREMENT OF VAPOR PHASE ORGANIC AND INORGANIC EMISSIONS BY EXTRACTIVE FOURIER TRANSFORM INFRARED (FTIR) SPECTROSCOPY - (This is already a self-validating Compliance (Reference) Method with its own QA/QC) PS-15 states- For System Validation, Since FTIR CEMS have multicomponent capability, it is possible to perform more than one RM simultaneously, one for each target analyte. Interpretation, If use EPA M320, 321, 301, etc, ASTM D6348 you can RATA w/ftir

5 Comparison PS/RM for FTIR Parameter PS-15 PS-18 Draft EPA M320 ASTM D ,12 M301 Dates Promulgated Feb 2000 Feb 2014? Feb 2000, Protocol 1995 Feb 2003, '10,'12 June 1991, '04, '11 Cal Gas Direct Accuracy 5%, 7% w/bias NA 2% or 5% 5% NA Dynamic Spike Recovery +-30% +-15% +-30% +-30% +-30% to 50% # of Spike Runs 24 (M301), 3 (M320) 6? Interference test No (just mentions them) <3% span combined No bias check No Method Relative Accuracy (DQO) 20% (RM in denom) 15% (Emiss Limit in denom) SO2 (10% Emiss Limit) PS2 < 15% 2.5% 2% Acc 10% Prec 5% t-test comparison "Bias" Correction Yes? ">30% is not valid method", but apply a corr factor May Yes, above 10% Calibration Error Test 10% 3 pt, <5%, intercept <15% of Span No One Knows No depends on RM Dry Cal check YES (All Compounds) Daily? Yes, but select set..no HCl Yes, but select set..no HCl depends on RM 7-Day Drift No 3% of span/day No No No Detector linearity 3 point, 2%/5% yes? 3 point, 2%/5% 3 point, 2%/5% NA Detection Limitations depends on RM LOS, MDC#3, LOD MAU, OFU MDC#1, MDC#2*, MDC#3 Cell Volumes per Data Pt. 10 spiking, 5 sample 5? 5 5 NA PLQ*, LOD Conf Intervals depends on RM 99%? 95% 95% 99% LOD, 95% t-test * Reviewed/Revised Manual Data Verification NA (Yes RATA RM) NA (Yes RATA RM) YES YES NO Calibration Transfer Standard (CTS) 5%? 5% 5% NA *MDC #2 = PLQ (no longer used)

6 FTIR is a Special Case Most of the Methods/PS were written with traditional CEMs in mind Traditional CEMS/GC are destruction techniques and as such change daily due many factors, i.e. ionization plates, fuel, gas conditioning FTIR is an optical technique where sample is not changed in any way Therefore, it DOES not change unless it is not operating properly If one compound does not perform 1 day, all of the compounds will be biased, but if one compound does perform, they will all perform EPA has stated, If EPA library reference spectra are not available, use calibration standards to prepare reference spectra according to Section 6 of the FTIR Protocol EPA is stating that, if the spectra are good, the numbers will be good Important point! Initial certification pass = very little ongoing QA/QC needed

7 FTIR Do not Drift or Change Response MKS Instruments 7

8 FTIR has come far (err mid) FTIR Requirements for CEM has been burdened to the point that much of the daily QA/QC and initial certification is unwarranted and will prevent its use in industry as newer technology QA/QC becomes more efficient (FTIR Rules Outdated)-Discriminatory 40 CFR Parts 72 and 75 [FRL ] RIN 2060 AG46 Acid Rain Program; Continuous Emission Monitoring Rule Revisions 75.33(d) would make it a violation of the primary measurement requirement 75.10(a) to allow the annual monitor data availability to drop below 80.0 percent for SO2, NOX, or CO2. (Docket A 97 35, Item II B 16). Consistent with current practices, the Agency would continue to expect CEMS to achieve high data availability.., monitor downtime in excess of 5.0 percent may warrant appropriate investigation and follow-up activities. Uptime = Credits = $

9 Current PS-15 Requirements not necessary today PS-15 Required Reason Whats Changed Detector Linearity Manufacturer performed New Boards and Algorithms and Performance Based Cell leak test X-axis accuracy Resolution Check CTS will determine if leaks present Redundant Will fail relative accuracy Only 1 manufacturer has a problem and dynamic spike test Will fail relative accuracy Redundant and dynamic spike test Audit Spike Dynamic spike with Audit is Good if conc correct 100%T Line 5% Req Current algorithms correct for this Used in place of Dynamic Spike Faster computers/more stabile Temperatures Audit Spectra Silly Not possible unless all spectral functions are provided Submit Spectra for Analysis to EPA Really? Signal to Noise Calculation Meaningless Need multiple soft wares and training. No one else is required to do this Will be determined by LOD/LOS Daily Dry Zero, Mid, Span or ALL TARGET COMPOUNDS Does not represent actual target compound response (Need H2O), Contaminates System Need to measure HCl, NH3, CH2O, HF, HCN and other polar species at very low levels If dry cal gas spans/etc are required, then certain cmpds will take hours

10 Cement Plant CEM Data with no Filter Change/Back-Purge for 3 Months- End of Period Test A steady-state is reached until the moisture changes Once dry, HCl is liberated in very high concentrations

11 Recommended On-Going PS-15 On-Going QA/QC Performance Specifications (After Initial Installation Certification): QA/QC Checks that should be required on a daily basis or other basis are as follows: Background Times are at the Discretion of Manufacturer Daily CEM System Zero (2% of 1 st Span) Daily - CTS indirect gas check, preferably using Ethylene or dilution of CO2/H2O (System Check) Daily - Dynamic spike check based on a minimum of at least 1 target compound. (Preferably the component that is expected to be the hardest to recover during the dynamic spiking test due to its chemical or reactive nature, adherence to the wetted components, or has the highest spectral interferences) (20% Recovery at 10% 50% expected or 5x MDL * Special Cases Options should exist for HCl/NH3 streams) Semi-Annual - RATA test with an acceptable reference method (Beware traditional CEMs such as Chemiluminesense or CO/CO2

12 Calibration Transfer Standard (CTS) The FTIR CEM, once validated is accurate and precise if functioning properly Indirect CTS gas checks the instrumentation and sampling system functionality Used to determine: Leaks within the sampling system T95 Rise and Fall times Instrument performance results for Resolution Signal to noise ratio (SNR) Linearity Frequency accuracy Sample cell path-length Instrument Line Shape (ILS) Noise Equivalent Area (NEA) Detection Limit (DL) Spectral limits Ensures that the correct Analytical Method is loaded

13 CTS Ethylene Wet or Dry

14 Detection Limits - Which One? Needs Modification and Consistent Terminology 1 set of data MKS Instruments 14

15 PS-15/PS-18 Detection Limitations Modifications Updating (~LOS) M301 The PLQ is a limit determined by the standard deviation of an estimate of a concentration; if the standard deviation of the estimate exceeds a threshold, then that estimate is unacceptable. The LOD is a limit determined by the estimate of the concentration itself (therefore PLQ = MDC#2) The LOD is clearly a threshold. An estimate that cannot be distinguished from one resulting from a blank sample is unlikely to provide meaningful results. 1. Prepare 7 samples standard LOD1 2. Std Dev = S1 3. LOD0 = 3S1 4. LOD1 2LOD0, then S0 = S1 5. LOD1 > 2LOD0, then: 6. 2 additional standards <LOD samples std dev each = S2, S3 8. Plot S1, S2, S3 as f(conc) 9. Draw Regression Line 10.Extrapolate to zero HCl Std Dev as f(conc) y = x LOD = 0.02 ppm Std as f(c) Linear (Std as f(c))

16 Span? Must be Defined for FTIR Each Cal Point is a Span Multi-Span in 1 Method Must Define Span PS15

17 % Recovery For Your Consideration? Typical dynamic spike involves diluting the CEM sample flow by 10% to get 50% addition 5 ppm native, use 25 ppm HCl cylinder diluted 10x = ~2.5 ppm added to 5 ppm native Theoretical CEM response = ~ 7.5 ppm HCl High NH3 slip Recovery vs. Spike Level (5 ppm native HCl) (10 percent dilution) ppm added to 5 ppm native HCl Greater than 50% Rule (162%) Matrix Effect - is it wrong? Spike Level (ppm) ASTM allows up to150% of Native Conc. Fail because not 10% DF? Why? Still reports 5 ppm at stack correct 50% of Native Rule or 10% Flow Rule Wrong?

18 Recommendations Rewrite/Modify/Update PS15 Allow substitution of ASTM D for M320 or Correct/Modify/Update M320 Standardize on Terminology Establish a sub-committee of outside interested parties/stakeholders made up of experienced field technicians/scientists/engineers in FTIR to provide recommendations to EPA on changes to PS15 and M320 Make it understandable to the layman Try to keep the Politics Out of the Science MKS Instruments 18