Secondary organic aerosol formation from smoldering and flaming combustion of biomass: a box model parametrization based on volatility basis set
<p>Residential wood combustion remains one of the most important sources of primary organic aerosols (POA) and secondary organic aerosol (SOA) precursors during winter. The overwhelming majority of these precursors have not been traditionally considered in regional models, and only recently we...
| Main Authors: | , , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2019-09-01
|
| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://www.atmos-chem-phys.net/19/11461/2019/acp-19-11461-2019.pdf |
| Summary: | <p>Residential wood combustion remains one of the most important sources of
primary organic aerosols (POA) and secondary organic aerosol (SOA)
precursors during winter. The overwhelming majority of these precursors have not been traditionally considered in regional models, and only recently were lignin pyrolysis products and polycyclic aromatics identified as the
principal SOA precursors from flaming wood combustion. The SOA yields of
these components in the complex matrix of biomass smoke remain unknown and
may not be inferred from smog chamber data based on single-compound systems.
Here, we studied the ageing of emissions from flaming and
smoldering-dominated wood fires in three different residential stoves,
across a wide range of ageing temperatures (<span class="inline-formula">−10</span>, 2
and 15 <span class="inline-formula"><sup>∘</sup></span>C) and emission loads. Organic gases (OGs) acting as SOA
precursors were monitored by a proton-transfer-reaction time-of-flight mass
spectrometer (PTR-ToF-MS), while the evolution of the aerosol properties
during ageing in the smog chamber was monitored by a high-resolution
time-of-flight aerosol mass spectrometer (HR-ToF-AMS). We developed a novel
box model based on the volatility basis set (VBS) to determine the
volatility distributions of the oxidation products from different precursor
classes found in the emissions, grouped according to their emission pathways
and SOA production rates. We show for the first time that SOA yields in
complex emissions are consistent with those reported in literature from
single-compound systems. We identify the main SOA precursors in both flaming
and smoldering wood combustion emissions at different temperatures. While
single-ring and polycyclic aromatics are significant precursors in flaming
emissions, furans generated from cellulose pyrolysis appear to be important
for SOA production in the case of smoldering fires. This is especially the
case at high loads and low temperatures, given the higher volatility of
furan oxidation products predicted by the model. We show that the oxidation
products of oxygenated aromatics from lignin pyrolysis are expected to
dominate SOA formation, independent of the combustion or ageing conditions,
and therefore can be used as promising markers to trace ageing of biomass
smoke in the field. The model framework developed herein may be
generalizable for other complex emission sources, allowing determination of
the contributions of different precursor classes to SOA, at a level of
complexity suitable for implementation in regional air quality models.</p> |
|---|---|
| ISSN: | 1680-7316 1680-7324 |