OP-FTIR: a Versatile and Powerful Technology for Measuring Multiple
Gaseous Compounds
Longdong Zhang1, Dr. Zaher Hashisho1
Dr. Long Fu2, Dr. Quamrul Huda2, Dr. Bonnie Leung2
1 Department of Civil and Environmental Engineering, University of Alberta
2 Alberta Environmental Monitoring, Evaluation and Reporting Agency
CPANS Annual Conference and General Meeting May 26 & 27, 2015
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Portable FID and PID
IR camera
Permanent installation of OP-FTIR
Outline
• Background
– Brief history; Instrumentation
• Capabilities and Limitations
• Applications in Different Areas
• Highlights of Select Projects
– Edmonton and Fort McKay
• Conclusions & Future Work
– Links to Alberta
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1905: a molecule’s IR spectrum can serve as a “chemical fingerprint” (William Coblentz)
1980s and 1990s: (benchtop) FTIR became dominant among IR technologies
1990: OP-FTIR became well developed
1971: Origin of OP-FTIR (Philip L. Hanst)
Background
Today: 44 years
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A picture of a benchtop (extractive) FTIR
Background (cont’d)
Source: GASERA
Gas
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Pump
Background (cont’d)
Schematic of a monostatic OP-FTIR spectrometer (Russwurm and Childers 2002)
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Background (cont’d)
• A typical configuration of air monitoring using OP-FTIR
Courtesy: KASSAY
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• IR absorbance spectra (“chemical fingerprints”) of 6 select compounds in clean air
Water
Nitrous Oxide
Carbon Monoxide
Ozone
Carbon Dioxide
Single Beam
Methane
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Capabilities & Limitations
• About 110 example compounds (U.S. EPA, 2011)
OP-FTIR Multi-
compounds; 24x7;
Digital; Low costs.
Fence-line monitoring
Workplace safety
Accidental spills
Loss prevention
/LDAR
Environmental compliance
Emissions inventories
& others
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Capabilities & Limitations (cont’d)
• Typical chemicals that can be measured:
• The most common criteria air contaminants: SOx, NOx, CO • Volatile Organic Compounds (VOCs): n-butane, ethylene,
formaldehyde, acetone, BTEX • Green House Gases (GHGs): CH4, CO2
• Odour compounds: e.g., ammonia • Detection limits: 1 ppb to tens of ppb
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Capabilities & Limitations (cont’d)
• Unsuitable ambient conditions could cause signal and data loss in field studies
Retro
Water (rain/dew) on a retroreflector
Retro in heavy dust
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Heavy rain
Applications in Different Areas
• Industrial areas – Upstream Oil & Gas Production (Segall et al. 2009); (Hashmonay
2012): Alkanes, BTEX, methanol and CH4
– Petrochemical Complex (Chan 2006): 39 air toxics including toluene, benzene and chloroform
– Paint manufacturing plant (Lin et al. 2008): 7 VOCs (toluene, m-xylene, p-xylene, styrene, methanol, acetone, and 2-butanone)
• Urban areas (Grutter et al. 2003); (Hong et al. 2004) – Trace gases over Mexico City: CH4, CO, propane, acetylene and
ethylene
– Ozone & VOCs in a park surrounded by heavy traffic roads: O3, NH3, CH4, CO and 26 VOC species
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Applications in Different Areas (cont’d)
• Agricultural areas (Karl et al. 2007); (Bai 2010); (Bjorneberg et al. 2009) – Biomass burning fire: About 20 GHGs and VOCs
– Beef & dairy cattle: CH4
• Natural areas (Horrocks et al. 2001); (Burton et al. 2010) – Volcanic emissions: SO2 & HCl
• Laboratories (Li et al. 2002) – Leaking gases: Methylene chloride, chloroform and acetone
• Other areas (Thoma et al. 2010) (Aneja et al. 2012) (Zhang et al. 2014) – Fugitive emissions from landfill applications: CH4
– Biosolids Lagoons: CH4, NH3 13
Applications in Different Areas (cont’d)
• Ongoing example projects involving OP-FTIR
– South Coast Air Quality Management District
– Texas A&M Institute of Renewable Natural Resources: shale gas industry
– Pipeline industry: leak detection
– Beijing, Taiwan and other cities
– Alberta
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Highlights of Select Projects
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2 1 FTIRs
Retro
#1: 125 m #2: 126 m
Prevailing wind
Biosolids Lagoon
Compost Piles
1 2
@ Compost Piles
Highlights of Select Projects (cont’d)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
13:48:00 14:16:48 14:45:36 15:14:24 15:43:12
Co
nc.
(p
pm
)
Time (HH:MM:SS)
NH3 UA #4 NH3 ESRD #4
Ratio: 0.9 to 1.1 (94% of data points)
16 @ Compost Piles
𝑛 ≡𝑈𝐶
𝑄= 𝑛𝑡 ≡
1
𝑁 2𝑈
𝑤0
𝑁
𝑖=1
Emission Rate: Q
Touchdown at U and w0
Sensor
Sonic Anemometer
A backward Lagrangian Stochastic model
Figure inspired by the teaching of Atmospheric Boundary Layer by Dr. John D. Wilson
U: mean horizontal wind speed (m/s) C: gas concentration N: number of particles released w0: vertical touchdown velocity nt: theoretical value of n Software: WindTrax (Thunder Beach Scientific) 17
@ biosolids lagoons
w2 w1
CO2/H2O analyzer
CH4 analyzer
Sonic anemometer
Path centres at 2.24 m
𝐹 ≈ 𝜌 𝑑𝑤′𝐶′
• ρd: mean air density; • w’: fluctuations of vertical
wind speed; • C’: fluctuations of gas
concentration
Software: EddyPro (LICOR)
C1
C1
C2
C2
Time 1 Eddy 1 Time 2 Eddy 2
air air
Reproduced from (Burba 2013)
The general principle is to measure • The number of molecules moving
downward and upward over time • Travelling speeds of these molecules
(Burba 2013)
@ biosolids lagoons 18
Highlights of Select Projects (cont’d)
Date Time CH4 IDT CH4 ECT IDT/ECT
10-3 kg/(m2-d) 10-3 kg/(m2-d) Ratio
Day 3 13:30 4.66 4.18 1.11
Day 3 14:00 5.23 4.31 1.22
Day 3 14:30 4.26 3.30 1.29
Day 3 15:00 4.49 4.04 1.11
@ biosolids lagoons
Note: IDT stands for Inverse Dispersion Technique; ECT stands for Eddy Covariance Technique.
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OP-FTIR at AMS1 in Fort
McKay
FTIR
Retro-reflector
177 x 2 m
FTIR
Retro-reflector
3.1 m 1.5 m
• August 22, 2014 – October 15, 2014 (54 days). Round-trip pathlength was 354 m; Sampling frequency was 1-min/sample, continuously; Heights of FTIR and retro-reflector were 3.1 m and 1.5 m, respectively.
@ Fort McKay AMS1 20
Highlights of Select Projects (cont’d)
0
20
40
60
80
08
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_0
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92
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_1
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_1
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31
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_2
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_1
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_0
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Co
nc.
(p
pb
)
Date_Time (MMDD_HHMM)
n-Butane n-Octane Ammonia Formaldehyde Methanol
Compound n-Butane
(ppb) n-Octane
(ppb) Ammonia
(ppb) Formaldehyde
(ppb) Methanol
(ppb)
Min 5.2 2.1 3.8 4.3 6.9
Max 73 44 22 5.7 14
Average 24.1 16.2 10.1 5.1 10.2
Median 19 14 4.5 5.2 10
No. of Hours Quantified 109 192 3 8 4
AAAQOG (1-hour) NA NA 2,000 53 2,000
Total Hours 1300 (54 days)
Total Effective Hours 1080 (83% of total hours)
21 @ Fort McKay AMS1
• Consistent trends of Non-Methane Hydrocarbon (NMHC) episodes between OP-FTIR and 55i (Thermo Fisher Scientific)
• NMHC by OP-FTIR = 3 x [n-butane (propane)] + 0 x [n-octane] (factor 3, propane (C3H8)).
-100
100
300
500
700
900
09
03
_1
63
4
09
03
_1
71
4
09
03
_1
75
4
09
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_1
61
0
09
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_1
65
0
09
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_1
73
0
09
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_1
81
0
09
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_1
85
0
09
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_1
93
0
09
06
_2
01
0
09
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_1
32
5
09
15
_1
40
5
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_1
44
5
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_1
52
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_1
60
5
09
16
_1
34
9
09
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_0
84
7
09
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_0
92
7
09
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_1
00
7
09
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_1
04
7
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_1
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7
10
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_1
90
9
10
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94
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_2
02
9
10
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51
5
10
10
_1
55
5
10
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_1
63
5
Co
nc.
(p
pb
)
Date_Time (MMDD_HHMM)
NMHC (OP-FTIR, best fit) NMHC (55i)
22 @ Fort McKay AMS1
Conclusions & Future Work
• OP-FTIR projects in Alberta (and around the world) have shown encouraging results.
• OP-FTIR is a versatile and powerful technology for air monitoring and we anticipate that it would become more widely used.
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Conclusions & Future Work
High hourly conc. of methane (13 ppm) and NMHC (400 ppb); lack of continuous VOC data (source: CASA) in the oil sands regions
Cattle farms in southern Alberta: ammonia (precursor) and GHGs
Vehicular formaldehyde; GHGs and odour
Chemical plants in Fort. Sask. and Red Deer areas: ethylene; 1,3-butadiene; and hydrocarbons
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http://albertacanada.com/
Acknowledgement
• AEMERA (JOSM) and AESRD (Ecotrust) for the funding support
• WBEA and AITF for the field support (Fort McKay project)
• Dr. Sunny Cho for her support with the biosolids lagoon work
• Colleagues in Dr. Hashisho’s lab for the field support (Clover Bar project)
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• Thank you for your attention
• Questions?
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