Wood-Smoke Source Contribution Along the …...Wood-Smoke Source Contribution Along the Wasatch Front Trends, Contribution & Low-Emission Devices Nancy Daher, Ph.D. Environmental Scientist
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Wood-Smoke Source Contribution Along
the Wasatch Front
Trends, Contribution & Low-Emission Devices
Nancy Daher, Ph.D.
Environmental Scientist
Utah DAQ
Wood-Smoke
Wood-Smoke: It Takes Your Breath Away!
NEI, 2011
PAHs, NOx, VOCs, CO
Human Hair (~60 µm)
PM2.5
Non-road Mobile 5.42%
On-road Mobile 21.6%
Point Sources 13.3%
Wildfires 0.03%
Area Sources (exc. RWC)
45.3%
Res. Wood Comb. (RWC)
14.3%
Primary PM2.5, Salt Lake County
Framework
Synopsis - Trends
Analysis Plan - Source Contributions - Exceedance Days
Sensitivity Analysis
- Low-Emission Wood-Burning Devices
Synopsis
Temporal Trends
Methodology
Measured Parameter
Sampling Method Sampling
Frequency Sampling duration
Wind speed/Direction
R. M. Young 5305 V 1-min
Aug. 2011-Apr. 2012 Temperature R. M. Young 41342 VC 1-min
Black Carbon (BC) Two-wavelength
Aethalometer, AE 22 5-min
Data from Sonoma Tech., Inc.
Delta-C of 0.5 µg/m3 0.5 µg/m3 of wood-smoke
Wood-smoke Characterization: Two-wavelength
Aethalometer
!! But delta-C is ONLY a QUALITATIVE measurement!!
Delta-C ~ Wood-Smoke Indicator
Au
gu
st
Se
pte
mb
er
Octo
be
r
Nove
mb
er
Dece
mb
er
Ja
nu
ary
Fe
bru
ary
Ma
rch
Ap
ril
Avera
ge t
em
pera
ture
(C
)
-5
0
5
10
15
20
25
30
Avera
ge d
elta-C
concentr
ation (
g/m
3)
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
Avera
ge w
ind s
peed (
m/s
)
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
Temperature
Delta-C
Wind speed
Delta-C & Temperature/Wind
Wildfires!
Winter
Hours
0 5 10 15 20
Avera
ge d
elta-C
concentr
ation (
g/m
3)
0.1
0.2
0.3
0.4
0.5
0.6
0.7
Weekday
Weekend
Delta-C - Diurnal Variation
Winter
PM2.5 > 25 ug/m3, exc. "no burn" days PM2.5 > 25 ug/m3 All PM2.5 samples
Ave
rage
de
lta
-C c
on
ce
ntr
atio
n (
g/m
3)
0.0
0.2
0.4
0.6
0.8
1.0
High Delta-C High PM2.5?
Summer Fall Winter Spring
R (PM2.5-deltaC) -0.01 0.40 0.55 0.34
0.53
0.25
0.71
Summary
Peak delta-C concentrations
Consistent with expected trends for domestic heating emissions
Increase in wood-burning emissions during high-PM2.5 episodes
Evidence of Wood-Burning Emissions
Analysis Plan
Source Contributions, Exceedance Days
Going Forward: Wood-Smoke Characterization
Objectives Quantify wood-smoke contribution
Investigate exceedance days
Compare to other source contributions
Wood-smoke Quantification: PMF Receptor
Modeling
• Apportions ~ all major sources
• Uses speciation data
• Higher accuracy if data complemented by levoglucosan
Measured Ambient Concentrations
(mass, ions, EC/OC, metals)
Known Source Characteristics/Tracer
Species
Source Contribution Estimates
+ LEVOGLUCOSAN
Wood-smoke marker
Levoglucosan Vs. Potassium
Onstad and Simpson. Puget Sound Clean Air Agency report, 2008
Seattle
w/o levoglucosan w/ levoglucosan
Levoglucosan = Wood-smoke marker
Wood-smoke Quantification: Methodology
Levoglucosan Analysis
Levoglucosan + Chemical Speciation Data
PMF
Wood-smoke & Major Source Contributions
Importance of Wood-Smoke in PM2.5
• Hawthorne (speciation site) • 24-hr PM2.5 FRM + SPECIATION samples • Jan 2015-Jan 2016
Going Forward: Routine Network Analysis
Measured Levoglucosan ? PM2.5, wood-smoke
Going Forward: Routine Network Analysis
𝑃𝑀2.5,wood−smoke =𝑃𝑀2.5𝑙𝑒𝑣𝑜𝑔.
× 𝑙𝑒𝑣𝑜𝑔.𝑚𝑒𝑎𝑠.
From PMF-resolved wood burning profile
Measured Levoglucosan
Emission Ratio: PM2.5/Levoglucosan
PM2.5, wood-smoke
To Burn or Not to Burn?
Impact of low-emission devices
Low-Emission Wood-Burning Devices
Hypothetical CHANGE-OUT program:
Existing wood-burning devices replaced by low-emission ones
Existing
Wood-Burning Devices
Catalytic/Non-catalytic
EPA-Certified Stoves
Catalytic/Non-Catalytic
EPA-Certified Inserts
Pellet Inserts
Pellet Stoves
Low-Emission Devices
Low-Emission Wood-Burning Devices
Hypothetical CHANGE-OUT program:
Existing wood-burning devices replaced by low-emission ones
𝐸𝑝𝑟𝑒 = 𝐸𝑖
𝐸𝑖 = 𝑐𝑜𝑟𝑑𝑠 𝑢𝑠𝑒𝑖 × 𝑤𝑜𝑜𝑑 𝑑𝑒𝑛𝑠𝑖𝑡𝑦 × 𝐸𝐹𝑖 × 𝑁𝑖
𝐸𝑝𝑜𝑠𝑡 = 𝑐𝑜𝑟𝑑𝑠 𝑢𝑠𝑒𝑖 × 𝑤𝑜𝑜𝑑 𝑑𝑒𝑛𝑠𝑖𝑡𝑦 ×𝜀𝑖𝜀𝑐𝑒𝑟𝑡
× 𝐸𝐹𝑐𝑒𝑟𝑡 × 𝑁𝑖
𝐶𝑀𝐴𝑄 𝐸𝑟𝑒𝑑𝑢𝑐𝑡𝑖𝑜𝑛 = 𝐸𝑝𝑟𝑒 − 𝐸𝑝𝑜𝑠𝑡
Wrapping Up
Levoglucosan Analysis + Speciation Meas.
PMF
Derivation of Emission Ratios
Sensitivity Analysis for Wood-Stove Emissions
Wood-Smoke Contribution to PM2.5
Impact of Low-Emission Devices
Routine Wood-Smoke Estimate
Thank you!
Questions?
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