MKS Analytical Method for HCl by FTIR

MKS Analytical Method for HCl by FTIR

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FTIR Analysis Method

Analytical Method– Classical Least Squares [CLS]– Predict chemical concentrations using spectroscopy (FTIR) and

linear algebra

Calibration Method– Requires certified gas or liquid standard – NIST Traceable– Collect signal/spectrum from FTIR– Combine and model using CLS– Analysis Region dependant upon component concentration

Determining Sample Gas Concentration– Run sample gas through FTIR gas cell– Collect signal/spectrum from FTIR– Use calibration model to predict sample gas concentration

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Calibration Summary

Region Selection– Select ALL regions where compound is present in the spectrum

Analysis Band– Select the largest peak region– Modify Analysis Band

Other compounds present in Sample Gas and interfereBulk gas or another component fully overlaps any of the analysisregion.

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NO Calibration Regions

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NO Calibration

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0.0%

0.5%

1.0%

1.5%

2.0%

2.5%

3

4

5

6

12

13

1420

21

22

28

29

30

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Machine Independent Calibration

Instrument to Instrument Variation Based on Ethylene Measurements (years 2000 - 2002)

Easily able to transfercalibrations from oneinstrument to another

Demonstration of instrument to instrument variability none of these instruments calibrated for Ethylene

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Analytical Interference Removal

Regions Change with Concentration– Change Analysis Regions

Higher resolution allows analysis in the presence of the interference (usually H20)Spectral Interference Correction (H2O)– Mask Interferences (‘picket fencing’)

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Different Regions for Different Concentrations

8% CO

100 ppm CO

20% CO2

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Low Resolution (2.0 cm-1)

Example of catalyst performance evaluationFigure used with permission from Johnson Matthey plc, Wayne, PA

SampleH2ONO

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High Resolution (0.5 cm-1)

Example of catalyst performance evaluationFigure used with permission from Johnson Matthey plc, Wayne, PA

Sample

H2O

NO

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Removing H2O Interference

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Removing H2O

Sample 150ppm NO in 35% H2O (white) 35% H2O (red)

Sample minus H2O (white) NO calibration (green)

NO Water

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No interference of waterHigh sensitivity

No artificial bias even in very high water (up to 40%)

Low detection limits

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Reduction of Sampling System Interferences

Sample Line TemperatureSample PressureReactive ComponentsMaterial Selection

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FT-IR Sampling System

Heated Probe with filtering– Metal or Glass– <0.1 um recommended (must keep particulate low)

Heated Sampling Line– MKS recommends SS not Teflon for most Apps– Minimum length as possible– Maintain Temp – 191 C normally– Maintain Pressure – 1.0 Atm (+/- 5% recommended)

Sampling Pump– Before or After FT-IR Gas Analyzer

Before be careful about contamination or sample lossAfter be careful not to let pressure go to low

– Additional Filtering Possible if before

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Field Deployable FTIR

Spike Recovery: cal gas 10% total flowCalibrated Gas Run: cal gas 7 lpm if pump pulls 5 lpm

Heated ProbeFilter Box

On-Off Valve

Rotometer

Sampling System

FTIR Gas Analyzer

Cylinder Spike Standardwith SF6 Tracer

Stack

Heated Lines

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Portland Cement Plants Continuous Emission Monitoring

National Emission Standards for Hazardous Air Pollutants From the Portland Cement Manufacturing Industry (40 CFR 63 SUBPART LLL)– Maximum Achievable Control Technology (MACT) Standards

First EPA mandated National Limits to Reduce Mercury and Other Toxic Emissions from Cement PlantsEPA issued final Portland Cement MACT in September 2010

Components required– NOx, SO2, HCl, CO, CO2, PM, THC, mercury

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HCl Measurements with FTIR

EPA Method 321– “Measurement of Gaseous Hydrogen Chloride Emissions At

Portland Cement Kilns by Fourier Transform Infrared (FTIR) Spectroscopy”

– Isolated sample analysis

EPA Method 7E – “Determination of Nitrogen Oxides Emissions From Stationary

Sources (Instrumental Analyzer Procedure)”– Describes general measurements requirements for all gases

when using a continuous instrumental analyzer

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HCl Measurements with FTIR

Sample (white) with 5 ppm HCland 12% water (red)

HCl peaks clearly visible after H2O subtraction

H2O subtraction

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HCl Measurements with FTIR (2)

HClcalibration peaks (red and green)

After HClsubtraction, only noise left

HCl subtraction

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No Interference of WaterHigh Sensitivity

No artificial bias even in very high water (up to 40%)

Low detection

limits

H2O steps up to 40%

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MG2030 CEM Ranges and Detection Limits

Component ppm mg/m3 CH4 0 - 21 0 - 15 CH4 0 - 70 0 - 50 CO 0 - 60 0 - 75 CO 0 - 120 0 - 150 CO 0 - 1200 0 - 1500 CO2 25% 25% H2O 40% 40% HCl 0 - 9 0 - 15 HCl 0 - 55 0 - 90 HCl 0 - 123 0 - 200 HF 0 - 11 0 - 10 N2O 0 - 26 0 - 50 N2O 0 - 51 0 - 100 N2O 0 - 255 0 - 500 NH3 0 - 13 0 - 10 NH3 0 - 99 0 - 75 NO 0 - 149 0 - 200 NO 0 - 299 0 - 400 NO 0 - 1119 0 - 1500 NO2 0 - 24 0 - 50 NO2 0 - 49 0 - 100 NO2 0 - 488 0 - 1000 SO2 0 - 26 0 - 75 SO2 0 - 105 0 - 300 SO2 0 - 699 0 - 2000

Component Detection limit CH4 0.3 ppm CO 0.5 ppm CO2 0.025%H2O 0.25%HCl 0.20 ppm HF 0.25 ppm N2O 0.1 ppm NH3 0.35 ppm NO 0.5 ppm NO2 0.4 ppm SO2 0.6 ppm

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Solution for Compliance of Portland Cement Plants

FTIR designed for Continuous Emission Monitoring– Thermoelectric detector, no need of liquid N2

HCl detection limit of 0.2 ppm– Calculated as 3-sigma in 25% H2O

Typical Gases and Ranges– CH4 0-21 ppm 0-70 ppm– CO 0-60 ppm 0-1200 ppm– CO2 0-25% (soon to 40%)– NOx 0-149 ppm 0-300 ppm– SO2 0-26 ppm 0-699 ppm– H2O 0-40%– HCl 0-9 ppm 0-55 ppm

FTIR associated with FID (THC), PM and mercury sensors for complete solution

Why MKS Over Competitors

Why MKS Over Competitors

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CEM FTIR

Advantages– Multiple species – one instrument

SO2, NH3, NO, HCl, HF, CO, CO2, H2O, and VOCs– Analyze components in high CO2 and H2O– Direct analysis – no chemical conversion or “fudge factors”– Analysis method minimizes interferents– Flexibility in Changing in Method

Customer can easily modify

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WHY MKS?

Fastest Acquisition with High Resolution (0.5cm-1)Smallest gas cell volume with long pathlength– 200 mL for 5.11m Path

Process Instrument– Not a Lab system converted to Process– Engineered for Process Environment– Gas Cell integrated heaters and pressure controller

Provide Method Development as well as Customer Support