Urban Ammonia Source Characterization Using Infrared Quantum Cascade Laser Spectroscopy

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Mark S. Zahniser Urban Ammonia Source Characterization Using Infrared Quantum Cascade Laser Spectroscopy NADP Ammonia Workshop October 2003 AERODYNE RESEARCH, Inc.

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AERODYNE RESEARCH, Inc. Urban Ammonia Source Characterization Using Infrared Quantum Cascade Laser Spectroscopy. Mark S. Zahniser. NADP Ammonia Workshop October 2003. NH 3 DETECTION WITH INFRARED SPECTROSCOPY. Strong infrared absorber  high sensitivity - PowerPoint PPT Presentation

Transcript of Urban Ammonia Source Characterization Using Infrared Quantum Cascade Laser Spectroscopy

Page 1: Urban Ammonia Source Characterization Using Infrared Quantum Cascade Laser Spectroscopy

Mark S. Zahniser

Urban Ammonia Source Characterization Using

Infrared Quantum Cascade Laser Spectroscopy

NADP Ammonia WorkshopOctober 2003

AERODYNE RESEARCH, Inc.

Page 2: Urban Ammonia Source Characterization Using Infrared Quantum Cascade Laser Spectroscopy

NH3 DETECTION WITHINFRARED SPECTROSCOPY

Strong infrared absorber high sensitivity Distinct absorption lines high selectivity Known molecular properties absolute

concentrations without calibration standardsBeer’s Law: A = N l

Methods:– Fourier Transform Infrared (FTIR)– Photoacoustic detection with CO2 laser (PA)– Tunable Infrared Laser Absorption (TILDAS)

» Near-IR » Mid-IR

• Lead-salt diode lasers (cryogenic cooling)• Quantum Cascade Lasers (new- TE cooling)

Page 3: Urban Ammonia Source Characterization Using Infrared Quantum Cascade Laser Spectroscopy

Cryogen-Free Pulsed QC Lasers

ADVANTAGES: Decreased Instrument Size and Weight Improved Laser Mode Stability Unattended Remote Monitoring “Turn-Key” Operation

DISADVANTAGES: Narrow Wavelength Tuning Increased Laser Line Width

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Compact QC Laser Spectrometer

56 m cell 0.1 s response time TE or LN2 Detectors 19 inch rack mount

MULTIPLE GASES– NH3-C2H4 (967 cm-1)

– CO2-N2O (2240 cm-1)– CH4-N2O-H2O (1270 cm-1)

Page 5: Urban Ammonia Source Characterization Using Infrared Quantum Cascade Laser Spectroscopy

NH3 at Iowa Swine Farm Automated single QC laser

instrument at 966 cm-1

Continuous operation for 4 weeks during ETV program

Enormous ammonia signals! 10 Hz data rate suitable for

eddy correlation

Page 6: Urban Ammonia Source Characterization Using Infrared Quantum Cascade Laser Spectroscopy

1.000

0.999

0.998

0.997

TRAN

SM

ISS

ION

967.40967.30FREQUENCY (cm

-1)

NH3 3 ppbpath 210 mP 50 Torr

data fit

AMMONIA IN ROOM AIR

5

4

3

2

1

0

NH

3 (p

pb)

250200150100500TIME (seconds)

55 ppt RMS noise (1 Hz)

Change from "tank" air to room air

AMMONIA DETECTION WITH QCL

Path Length 210 m Line Width 0.006 cm-1

(180 MHz)

PRECISION 55 ppt Hz-1/2

3x10-5 absorbance

Page 7: Urban Ammonia Source Characterization Using Infrared Quantum Cascade Laser Spectroscopy

U. Manchester Inst. Technol. QC-TILDAS

NH3 - NO - NO2 at Chelmsford UK Field Site August 2003

60

50

40

30

20

10

0

AM

MO

NIA

(ppb

)

8:50 AM8/10/2003

8:52 AM 8:54 AM

TIME

HAND AT INLETSILICO-STAINLESS TUBE LENGTH 10 m

Page 8: Urban Ammonia Source Characterization Using Infrared Quantum Cascade Laser Spectroscopy

ViewOpen-path FTIR in Mexico CityOpen-path FTIR in Mexico CityMichel Grutter, Edgar Flores, Roberto Basaldud Centro de Ciencias de la AtmósferaUniversidad Nacional Autónoma de México (UNAM)

Page 9: Urban Ammonia Source Characterization Using Infrared Quantum Cascade Laser Spectroscopy

Set UpOPEN PATH FTIR SPECTROMETEROPEN PATH FTIR SPECTROMETER (Grutter et al.)(Grutter et al.)

Compounds: NH3, O3, CO, NO, N2O, CO2, CH4, HCHO

sample

references

100 – 500 m

detectorspectrometer

Page 10: Urban Ammonia Source Characterization Using Infrared Quantum Cascade Laser Spectroscopy

NHNH3 3 FTIR SPECTRUM in MEXICO CITY (Grutter et al.)FTIR SPECTRUM in MEXICO CITY (Grutter et al.)

Sun Apr 06 05:25:08 2003

NH3 100 ppb

92.9 ppb

NH3

MixingRatios (ppb)

100

50

0

Page 11: Urban Ammonia Source Characterization Using Infrared Quantum Cascade Laser Spectroscopy

Mexico City NH3 FTIR Data 0

45

90

135

180

225

270

315

0 0.02 0.04 0.06 0.08 0.1

0 2 4 6 8 10 12 14 16 18 20 22 24

0.000

0.010

0.020

0.030

0.040

0.050

0.060

hrN

H3 (

ppm

)

a) b)

0 0.02 0.04 0.06 0.08 0.1N H 3 (ppm )

360

400

440

480

CO

2 (pp

m)

Fit R e su lts

Fit 1 : L in ea rEqu a tio n Y = 1 16 6 .64 5 6 2 2 * X + 36 3 .02 9 87 4 3N u m b e r o f d a ta p o in ts u se d = 7 2 8 6Ave ra ge X = 0 .02 2 1 8 0 9Ave ra ge Y = 38 8 .9 0 7R e sid ua l su m o f sq ua re s = 1 .4 4 2 4 3 E+0 0 6R e gre ssio n sum o f sq u a re s = 1 .6 5 9 75 E+0 0 6C o e f o f d e te rm in a tio n , R -sq ua re d = 0 .5 35 0 2 8R e sid ua l m ea n sq u a re , sigm a -h a t-sq 'd = 19 8 .0 2 7

DIURNAL CYCLEAPRIL 2003

CO2 CORRELATION0.9 mmol NH3/mol CO2

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MEXICO CITY AIR POLLUTION STUDY, APRIL 2003

QCL (NH3)Dual TDL (NO2, HCHO)

REAR INLET

FRONT INLET

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AMMONIA INLET DESIGN

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650600550500450400

CO2 (ppm)

7:14 PM4/24/2003

7:16 PM 7:18 PM 7:20 PM

80

60

40

20

NH3 (ppb)

80

60

40

20

NH

3 (p

pb)

650600550500450400

CO2 (ppm)

0.12 mmol NH3 / mol CO2

General Traffic & Market AreaMexico City, 2003

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Mexico City Automobile Traffic

Page 19: Urban Ammonia Source Characterization Using Infrared Quantum Cascade Laser Spectroscopy
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BOSTON TUNNEL NH3

1600

1200

800

400

CO2 (ppm)

2:42 PM5/23/2003

2:44 PM 2:46 PM 2:48 PM 2:50 PM

120

80

40

NH3 (ppb)Exit Tunnel

Enter Tunnel

120

100

80

60

40

20

0

NH

3 (p

pb)

16001200800

CO2 (ppm)

0.1 mmol NH3 / mol CO2

Boston 'Big Dig' Tunnel

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460

440

420

CO2 (ppm)

6:15:30 PM5/23/2003

6:16:00 PM 6:16:30 PM

20

15

10

NH3 (ppb)

20

15

10

NH

3 (p

pb)

460440420

CO2 (ppm)

0.2 mmol NH3 / mol CO2

BOSTON HIGHWAY NH3

FREEWAY OVER-PASS

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QUAD-QC OPEN PATH TILDAS

Four QC Lasers with time-multiplexing

NO, NO2, N2O, NH3,CO

CO2 reference Cross-road retro-

reflector Range 200 meters

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AUTOMOBILE EXHAUST PLUME SPECTRA

LASER 12240 cm-1

LASER 2967 cm-1

LASER 31906 cm-1

CO2

N2ONH3

NO

0.02 s

Page 24: Urban Ammonia Source Characterization Using Infrared Quantum Cascade Laser Spectroscopy

Automobile exhaust plume

8

6

4

2

0

CO

2, %

0.80.60.40.20.0TIME (s)

40

30

20

10

0

N2O

, ppm

60

40

20

0

NH

3, p

pm300

250

200

150

100

50

0

NO

, ppm

1994 Mitsubishi mmol/mol CO2 CO2 N2O 0.46 NH3 0.83 NO 3.4

start of plume

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CATALYTIC CONVERTER WARM-UP

0

200

400

600

800

NO

, ppm

0 2 4 6 8 10 12CO2, %

cold start t = 93 s t = 133 s t = 172 s t = 208 s t = 244 s t = 280 s

0

20

40

60

80

NH

3, p

pm

0 2 4 6 8 10 12CO2, %

cold start t = 93 s t = 133 s t = 172 s t = 208 s t = 244 s t = 280 s

NO NH3

REPEATED PASSES OF SAME AUTOMOBILE0 - 5 minutes after cold start

NO emissions decrease

NH3 emissions increase

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CATALYST WARM-UP

0

2

4

6

8

10N

O E

mis

sion

Rat

io (m

mol

/mol

CO

2)

6005004003002001000Time from cold start (s)

0

0.2

0.4

0.6

0.8

1.0

NH

3 an

d N

2O E

mis

sion

Rat

ios

(mm

ol/m

ol C

O2)

0

NH

3 E

mis

sion

Rat

io (m

mol

/mol

CO

2)

*

* *

*

**

*

NO N2O (expanded scale) NH3 (expanded scale)

NO N2O (N2) NH3

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CONCLUSIONS

QC LASER METHOD FOR NH3 – OPEN PATH – EXTRACTIVE SAMPLING

MOBILE “MAPPING” FOR SOURCE IDENTIFICATION AND QUANTIFICATION

AUTOMOBILE EXHAUST IS SIGNIFICANT SOURCE OF URBAN AMMONIA FROM CATALYTIC REDUCTION OF NO

Page 28: Urban Ammonia Source Characterization Using Infrared Quantum Cascade Laser Spectroscopy

Acknowledgments Aerodyne Colleagues

– Joanne Shorter – Scott Herndon – David Nelson– Barry McManus– Quan Shi– Patrick Kirwin– Jeff Mulholland– Chuck Kolb

UNAM (FTIR)– Michel Grutter

M.I.T– Ed Dunlea– Luisa Molina– Mario Molina

US EPA, NSF, NASA, DOE, NISTSmall Business Innovation Research Programs

Alpes Lasers– Antoine Meuller– Yargo Bonnetti

U. Manchester Inst. Tech.– Martin Gallagher– Keith Bower– Jamie Whitehead

Danish Inst. Agriculture Sci– Willem Asman – Anton Thomsen– Kirsten Schelde