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?