Biomass burning plume chemistry: OH-radical-initiated oxidation of 3-penten-2-one and its main oxidation product 2-hydroxypropanal
<p>In order to enlarge our understanding of biomass burning plume chemistry, the OH-radical-initiated oxidation of 3-penten-2-one (3P2), identified in biomass burning emissions, and 2-hydroxypropanal (2HPr) was investigated at 298 <span class="inline-formula">±</span> 3 K...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2021-12-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://acp.copernicus.org/articles/21/18557/2021/acp-21-18557-2021.pdf |
| Summary: | <p>In order to enlarge our understanding of biomass burning
plume chemistry, the OH-radical-initiated oxidation of 3-penten-2-one (3P2),
identified in biomass burning emissions, and 2-hydroxypropanal (2HPr) was investigated at 298 <span class="inline-formula">±</span> 3 K and 990 <span class="inline-formula">±</span> 15 mbar in two atmospheric
simulation chambers using long-path FTIR spectroscopy. The rate coefficient
of 3P2 <span class="inline-formula">+</span> OH was determined to be (6.2 <span class="inline-formula">±</span> 1.0) <span class="inline-formula">×</span> 10<span class="inline-formula"><sup>−11</sup></span> cm<span class="inline-formula"><sup>3</sup></span> molec.<span class="inline-formula"><sup>−1</sup></span> s<span class="inline-formula"><sup>−1</sup></span> and the molar first-generation yields for
acetaldehyde, methyl glyoxal, 2HPr, and the sum of peroxyacetyl nitrate (PAN) and CO<span class="inline-formula"><sub>2</sub></span>, used to
determine the CH<span class="inline-formula"><sub>3</sub></span>C(O) radical yield, were 0.39 <span class="inline-formula">±</span> 0.07,
0.32 <span class="inline-formula">±</span> 0.08, 0.68 <span class="inline-formula">±</span> 0.27, and 0.56 <span class="inline-formula">±</span> 0.14, respectively,
under conditions where the 3P2-derived peroxy radicals react solely with NO.
The 2HPr <span class="inline-formula">+</span> OH reaction was investigated using 3P2 <span class="inline-formula">+</span> OH as a source of
the <span class="inline-formula"><i>α</i></span>-hydroxyaldehyde adjusting the experimental conditions to shift
the reaction system towards secondary oxidation processes. The rate
coefficient was estimated to be (2.2 <span class="inline-formula">±</span> 0.6) <span class="inline-formula">×</span> 10<span class="inline-formula"><sup>−11</sup></span> cm<span class="inline-formula"><sup>3</sup></span> molec.<span class="inline-formula"><sup>−1</sup></span> s<span class="inline-formula"><sup>−1</sup></span>. Employing a simple chemical mechanism to
analyse the temporal behaviour of the experiments, the further oxidation of
2HPr was shown to form methyl glyoxal, acetaldehyde, and CO<span class="inline-formula"><sub>2</sub></span> with
estimated yields of 0.27 <span class="inline-formula">±</span> 0.08, 0.73 <span class="inline-formula">±</span> 0.08, and 0.73 <span class="inline-formula">±</span> 0.08, respectively.</p> |
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| ISSN: | 1680-7316 1680-7324 |