Update on Aerodyne development of PAM oxidation flow reactor
Andy Lambe, John Jayne, Wade Robinson, Xavier Cabral, Stephen PrescottAerodyne Research, Inc.
Bill BrunePennsylvania State University
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AERODYNE RESEARCH, Inc. 45 MANNING ROAD, BILLERICA, MA 01821 (978) 663 9500
www.aerodyne.com CACC_OPT_12_1
E. Kang, M. J. Root, D. W. Toohey, and W. H. Brune, Introducing the concept of Potential Aerosol Mass (PAM), Atmos.
Chem. Phys., 7, 5727–5744, 2007.
A. T. Lambe, A. T. Ahern, L. R. Williams, J. G. Slowik, J. P. S. Wong, J. P. D. Abbatt, W. H. Brune, N. L. Ng, J. P. Wright,
D. R. Croasdale, D. R. Worsnop, P. Davidovits, and T. B. Onasch, Characterization of aerosol photooxidation flow re-
actors: heterogeneous oxidation, secondary organic aerosol formation and cloud condensation nuclei activity measure-
ments, Atmos. Meas. Tech., 4, 445–461, 2011.
D. S. Tkacik, A. T. Lambe, S. Jathar, X. Li, A. A. Presto, Y. Zhao, D. R. Blake, S. Meinardi, J. T. Jayne, P. L. Croteau,
and A. L. Robinson, Secondary organic aerosol formation from in-use motor vehicle emissions using a Potential Aerosol
Mass reactor. Environ. Sci. Technol., 48, 11235-11242, 2014.
R. Li, B.B. Palm, A.M. Ortega, J. Hlywiak, W. Hu, Z. Peng, D.A. Day, C. Knote, W.H. Brune, J. de Gouw, and J. L. Jime-
nez. Modeling the radical chemistry in an Oxidation Flow Reactor: radical formation and recycling, sensitivities, and OH
exposure estimation equation. J. Phys. Chem. A, 2015.
PAM Wiki: https://sites.google.com/site/pamwiki/
Figure demonstrating PAM capabilities
Oxidant production in the PAM reactor
PAM overview
O2 + hv185 2O(3P)
O(3P) + O2 O3
O3 + hn254 O(1D) + O2
O(1D) + H2O 2OH
H2O + hn185 OH + HH + O2 HO2
• Field-deployable oxidation flow reactor developed by Bill Brune[Kang et al., ACP, 2007] and further evaluated by Lambe et al. (2011)
• Production of secondary aerosol, oxidized primary aerosol
• https://sites.google.com/site/pamwiki/publications [search ‘PAMwiki’]
https://sites.google.com/site/pamwiki/publications
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Co
nce
ntr
atio
n (µ
g m
-3)
1.0
0.5
0.0NO
2/N
Ox
0 hours
7 hours
14hours
3days
5days
9days
Photochemical age
NH4OrgSO4NO3
16:00 16:30 17:00 17:30 18:0015:30
Local Time
18:30
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• PAM OH concentrations range from 2.0 × 108 to 2.2 ×1010 molec cm−3 with exposure times of 100 s.
• Environmental chamber OH concentrations range from 2 × 106 to 2 × 107 molec cm−3
with exposure times of several hours.
ARI PAM Reactor Package
• Mounted in an enclosure.• More efficient fluorescent
lamps with electronic diming.
• Two interchangeable lamp options (λ= 185, 254 nm) to decouple O3 production in the cell.
• Separate O3 production cell.
• Control electronics and software for running event sequences.
ARI PAM Oxidation Flow Reactor
• Penn State PAM reactor design & new UV lamps with dimmable ballasts
• Ozone generator with lamp/dimmable ballast
• UV photodetector, RH/T sensors, Nafion humidifier, Aerodyne autovalve
• Control software with data-logging, automated control with event sequencing
• Penn State photochemistry model for predicting HOx radical concentrations atspecified operating conditions
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• PAM units supplied with two interchangeable O3-free lamps (l = 254 nm) todecouple O3 and OH production if needed
• Lamps mounted inside GE214 quartz sleeves and flushed with N2 gas
O3 formation potential (l = 185, 254 nm)
Ultraviolet C photodetector
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• Mounted in back end plate for in situ UV measurement• Connect to OH exposure (calibrated with SO2, CO, etc.) and Penn State
photochemical model • UV lamp diagnostic
• Test data: Measured irradiance of two UV lamps (l = 254 nm)
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END
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High Output (HO) Quartz LampsHigh Output (HO) lamps yield up to 66% more UV output when compared to
standard lamps of the same length. HO lamps offer system designers unique
opportunities to decrease the number of lamps required without compromising
functionality of the system. This has the added potential benefits of reduced
system footprint, increased efficiency and/or increased system capacity.
HO lamps are produced and are available in the same configurations of standard
lamps. Custom lengths and configurations may also be produced to the customer's specific requirements.
The table below represents a sampling of the more common lamp sizes. We can custom design the ideal HO lamp
for your unique application.
High Output (HO) Quartz Germicidal Lamps
Preheat&
Instant StartConfigurations
Available!
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Tube Arc UV output1 Rated1
Diameter BF - BF Length Power1 Current Voltage1 @ 254nm Life
mm mm mm W mA V µW/cm² W hrs.
Low Ozone
GHO436T5L 15 436 360 48 800 60 120 13 16,000
GHO36T5L 15 842 755 87 800 110 260 28 16,000
GHO846T5L 15 846 767 90 800 113 265 29 16,000
GHO893T5L 15 893 815 95 800 120 270 30 16,000
GHO64T5L 15 1554 1421 155 800 195 395 54 16,000
Ozone Generating
GHO436T5VH 15 436 360 48 800 60 120 13 16,000
GHO36T5VH 15 842 755 87 800 110 260 28 16,000
GHO846T5VH 15 846 767 90 800 113 265 29 16,000
GHO893T5VH 15 893 815 95 800 120 270 30 16,000
GHO64T5VH 15 1554 1421 155 800 195 395 54 16,000
Note 1: Lamp data is based on measurements performed under laboratory conditions in air at room ambient temperature. Measurements were performed on a high-frequency, current limited electronic ballast and represent average values at 1 meter.
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software
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