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

MKS InstrumentsOn-Line Product Group2 Tech Drive, Suite 201

Andover, MA 01810Tel: 978-482-5364

MultiGas™ FT-IRAutomated HCl CEM Systems

California Desert Air Working Group

November 13-14, 2013Las Vegas, NV

Peter G. Zemek, Ph.D.

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

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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 HCl CEMS 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

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

Validation and On-Going HCl CEM PS-18

1. Before Installation, instrument manufacturer must perform:a. Linearityb. Detection Limitc. Cross Sensitivity

2. After Installation to Validate must perform:a. RATA Test on Other than HCl compoundsb. Reference Method Test HCl - EPA-M321 RATA

a. Includes Dynamic Spikec. 7 day drift test

3. Daily and On-Going (all automated)a. Zerob. Dynamic Spike or Dry Cal Span (Wet or Dry)c. Periodic RATAd. Provide 30 day rolling avg HCl

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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)

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What is 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 an Interferogram.

A computer converts the Interferogram to an Absorbance spectrum which is Linear

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MKS IR Spectroscopy Hardware

• Source: Blackbody (Hot Silicon Carbide ~ 1300 K)

• Modulator: Interferometer • Sample: Vapor (Gas Cell, 10, 5.11m, 35cm, or 2cm path lengths)

• Detector: Mercury Cadmium Telluride (MCT) Quantum Detector cooled by Thermoelectrically (TE) Peltier

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IR SourceTo Gas Cell & Detector

Beamsplitter Moving Mirror

Fixed MirrorHeNe Laser monochromatic light

Creating the InterferogramThe FT-IR Light Modulator

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FTIR From Igram to Spectrum

Interferogram Single Beam Normal ModeAbsorbance Spectrum ready for speciation

Apodizing then FFT

A = -Log(I/Io)

1. Create Interferogram then send to detector (Modulator)2. Amplify Interferogram (preamp) then digitize it (A/D converter)3. Send digital signal to computer (PC)4. Apply Fourier Transform math to Interferogram, result is Spectrum (I)5. Remove background noise signals (Io) from Sample (I) 6. Result is Absorbance gas spectrum (A) used to identify the

different species

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Background and Sample

BACKGROUND (Io)N2 Purge

SAMPLE (I)1000 ppm NH3

Absorbance = - Log (I/Io)

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Absorbance is Proportional to Concentration

FFT of Sample1000 ppm NH3

Absorbance = - Log (I/Io)Absorbance = • C • path

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FTIR Analysis MethodAnalytical Method

– Classical Least Squares (CLS) thenBeers Law, Abs = a b c measured spectruma absorptivity coefficient or ε from calibrationb 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

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Classical Least Squares

1 1 1

2 2 2

a a b b

a a b b

A K C K C

A K C K C

Based on Beer’s Law Relatively fast computationally More complex mixtures Wavelengths used need to be

greater than #components Noise reduced as #s increase

1 2

a

b

a+b

WAVELENGTH

AB

SOR

BA

NC

E

CLS Spectral Analysis Finds factors for all reference spectra in method/recipe to recreate the sample spectrum

Powerful Technique - CLS for HCl Measurements with FTIR

Sample (white) with 5 ppm HCl and 12% water (red)

HCl peaks clearly visible after H2O subtraction

H2O subtraction

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Powerful Technique - CLS for HCl Measurements with FTIRHCl calibration peaks (red and green)

After HCl subtraction, only noise left

HCl subtraction

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Examples of Pre-Abatement Coal Fired (Cement Plant) Gas Concentrations Measured by FTIR

Plant 1 Plant 2 Plant 3 Plant 4 Plant 5 Plant 6

HCl 5-300 0-5 0-4 <1 <1 2-4SO2 0-60 0-200 0-240 0* 300-400 <1

NOx 250-450* 300-600 100-400 100-300 ~ 150 ~ 800CH2O 5-25 0-3 3-9 2-3 ~ 20 ~ 3

*NH3 0-150 0-40 0-80 0-50 ~30 0-15

CO 200-400* 100-600* 100-200* 100-600* ~ 300 300-700

CH4 ~ 2 ~ 2 ~ 2 ~ 2 ~ 2 ~ 5

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* 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)

19 19Time

HC

l Con

cent

ratio

n (p

pm)

Examples of HCl Concentration Profiles at Cement Plants – RM

On/OffRaw Mill OFF Raw Mill ON

TÜV ranges & uncertainties MKS 2030D TE9 CEM FTIR

Gas comp.

Cert. range Supp. range 1

Supp. range 2

ELV U/C U/C req.

NH3 0-10 mg/m3 0-75 mg/m3 - 10 mg/m3 6.2% 30.0%

CO 0-75 mg/m3 0-300 mg/m3 0-1500 mg/m3 50 mg/m3 6.2% 7.5%

SO2 0-75 mg/m3 0-300 mg/m3 0-2000 mg/m3 50 mg/m3 7.0% 15.0%

NO 0-200 mg/m3 0-400 mg/m3 0-1500 mg/m3 130 mg/m3 6.8% 15.0%

NO2 0-50 mg/m3 0-100 mg/m3 0-1000 mg/m3 50 mg/m3 4.1% 15.0%

HCl 0-15 mg/m3

0-10 ppmv0-90 mg/m3 0-200 mg/m3 10 mg/m3 8.1% 30.0%

HF 0-3 mg/m3 0-10 mg/m3 - 1 mg/m3 19.3% 30.0%

CH4 0-15 mg/m3 0-50 mg/m3 - 10 mg/m3 7.0% 22.5%

CO2 0-25% - - 0-25% 3.3% 7.5%

H2O 0-40% - - 0-40% 3.4% 7.5%

N2O 0-50 mg/m3 0-100 mg/m3 0-500 mg/m3 50 mg/m3 4.5% 15.0%

1 ppm HCl = 1.49 mg/m3

FTIR Suppliers - TÜV Ranges & UncertaintiesSO2 Cert. range Supp. range 1 Supp. range 2 Rel. U/C

MKS 0-75 mg/m3 0-300 mg/m3 0-2000 mg/m3 7.0% of 50 mg/m3

Comp 1 0-75 mg/m3 0-300 mg/m3 0-1500 mg/m3 9.4% of 50 mg/m3


Comp 3 0-75 mg/m3 0-300 mg/m3 - 9.4% of 50 mg/m3


HCl Cert. range Supp. range 1 Supp. range 2 Rel. U/C

MKS 0-15 mg/m3 0-90 mg/m3 0-200 mg/m3 8.1% of 10 mg/m3



Comp 3 0-15 mg/m3 - - 12.8% of 10 mg/m3


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 possibleSCR, 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

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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

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NEW: High-Sensitivity FTIR HCl Analyzer for CEM

HCl detection limit 0.03 ppm (30 ppbv) plus biasHot and Wet – 200mL Sample VolumeNo liquid nitrogen (LN2) neededNo N2 Background → easier integration than

standard FTIR – turn on and goNo Calibration Needed– “Canned” MethodCan measure HCl, CH2O, HF, H2O, N2O, CH4 with

similar high sensitivity – or ELIMINATE Spectral Regions of no concern –hardware based

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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

Transferrable Hardware & Software

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Detector/Hardware InfluencesHigh Sensitivity System HCl, HF, CH4, H2O, N2O, CH2O

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TE9u CEMLN2-16u MCT (77K)TE-HS CEM

Sensitivity (signal)

<noise

>S/N

IR Band-pass Filters

spectral region

0

20

40

60

80

100

120

140

0

200

400

600

800

1000

1200LN2-16 - HCl

HCl ppm (100) 191C H2O% (40) 191C CH4 (3000) 191C (2of2)

Time

HCl B

itum

coa

l wet

ppm

vC

H4 ppm

v

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EXAMPLE of No Cross Sensitivity

No change in HCl concentrationSpike @ 900 ppm CH4 and 6% H2O

Staged Blowback Filtration 80 psig

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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%

MKS FTIR CEM Data 15 Days

H2O vs. HCl in CEM Cement Extractive SystemNo 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%

HCl CEM Dynamic Spiking

EPA Method 320 Calculations and LOD Calculations

Parameter:

Formaldehyde

Reference ID R000008 slope 6.81 x 10-7Reference Conc. (ppb-m/k) 0.38071066 interc -0.00194Reference Band Area 0.007 CL (at Ls, 250F) 1.00Reference FCU 10 FL (cm-1) 2735.72LS (m) 1 FU (cm-1) 2843.67DL (ppb-m/k) 0.025445 FU-FL 107.95DL (Ls, 250F) 10.0 Scaling Factor for AAI 0.006667AU 0.1 AAI (abs cm-1) 0.000700CL (ppb-m/k) 0.0025 RMSD 0.0000254eqna 0.002745 MAU (ppb-m/k) 0.0100

MAU (at Ls, 250F) 3.93

Which LOD/LOQ/MAU/MDC?

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• 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

ASTM D6348-98 LOD CalculationsFormaldehydeForm-MDL Temperature & Pressure Adjusted (ppbv)

Form. Error +- (ppb) (X-X mean) (x-xmean)^21 std deviation

T0000003 6/19/02 15:30 0.7224 0.05157 0.00482 2.32E-05T0000004 6/19/02 15:30 0.7275 0.05144 0.00992 9.84E-05T0000005 6/19/02 15:31 0.71756 0.05317 -2E-05 4E-10T0000006 6/19/02 15:31 0.72292 0.05368 0.00534 2.85E-05T0000007 6/19/02 15:32 0.71942 0.0568 0.00184 3.39E-06T0000008 6/19/02 15:32 0.71047 0.05921 -0.00711 5.06E-05T0000009 6/19/02 15:33 0.70279 0.05997 -0.01479 0.000219

0.71758 0.05512 -9.5E-17 6.04E-05MDC = Minimum Detectable Concentration

MDC (ppm)= 3*sqrt{((1/P)sum(C mean-C mp)}

FormaldehydeMDC= 0.023316 ppbplus error bias * 0.078436 ppb*method #1 of Annex A2 of ASTM D6348-98 (revision)Resolution 1.0 cm-1 at 128 sc background, 1atm, 1gain, 121CApodization- triangular, phase correct- mertz, baseline- linear

NIOSH Method 3800 LOD Calculation

LOD (ppb) = {(CCP) x (RSA)} / {(L) x (Ar)}

CCP = Reference Spectrum Concentration Pathlength Product (ppb-m) RSA = Residual Squared Area after subtraction of interfering species, primarily two water spectra (abs-cm-1) L = Cell Pathlength (M) Ar = Absorption Area of a Reference Spectrum in the region chosen for analysis (abs-cm-1)

Formaldehyde Ref Spectrum Midac 1.0 cm-1 Region Selected (L,R) 2843.67 2735.72 CCP 1500 ppb-m Interfering Spectra 1 H20 2 7 % moisture Interfering Spectra 2 H20 4 10 % moisture Pathlength 10 meters Ar Baseline Adjusted 0.073 abs-cm-1

RSA Baseline Adjusted 0.003 abs-cm-1

RSA*(x) (conservative Factor) x= 1 0.003 abs-cm-1

Formaldehyde LOD = 6.16 ppbv

Detection Limits - Which One?

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1 set of data

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

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Manual CheckTE-HS LODSoftware Included

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CH4 12 ppm

HCl 30 ppb

Goodness of Fit-2x sigma

Comparison of HCl CalibrationsPrecision

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0.00 20.00 40.00 60.00 80.00 100.00 120.00 140.00 160.00 180.000

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5TE-HS, TE9

TE5 HClTE9 HCl

Elapsed minutes (min)

HCl P

erm

Tub

e pp

mv

wet

Diff 3.5/3.3 = 5.7%Teflon Lines w/cold spots

Q= 50 sccm

Hitran and Hovacal Calibration

Comparison of MKS FTIR Analyzers Solutions for HCl

HCl DL*(30 sec)

Main Components

MeasuredInformation

Broadband CEMTUV CertifiedEPA Certified

<300 ppb

HCl, SO2, NOx, CO, CO2, H2O, NH3, HF, N2O, CH4, CH2O

• No LN2 needed• Requires daily N2

Zero

High-sensitivityHCl FTIR

EPA Certified

<30 ppb HCl, Formaldehyde, HF, CO, CO2, CH4

• No LN2 needed• No daily N2 Zero• Uses Auto-Reference

method

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* Detection Limit based upon 3σ in 30% H2O and 25% CO

mks instruments on-line product group 2 tech drive, suite 201 andover, ma 01810 tel: 978-482-5364

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