Unexplored volatile organic compound emitted from petrochemical facilities: implications for ozone production and atmospheric chemistry

• Main Authors: C. Sarkar, G. Wong, A. Mielnik, S. Nagalingam, N. J. Gross, A. B. Guenther, T. Lee, T. Park, J. Ban, S. Kang, J.-S. Park, J. Ahn, D. Kim, H. Kim, J. Choi, B.-K. Seo, J.-H. Kim, S. B. Park, S. Kim
• Format: Article
• Language: English
• Published: Copernicus Publications 2021-08-01
• Series: Atmospheric Chemistry and Physics
• Online Access: https://acp.copernicus.org/articles/21/11505/2021/acp-21-11505-2021.pdf
• ISSN: 1680-7316; 1680-7324

<p>A compound was observed using airborne proton transfer reaction time-of-flight mass spectrometry (PTR-TOF-MS) measurements in the emission plumes from the Daesan petrochemical facility in South Korea. The compound was detected at <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M1" display="inline" overflow="scroll" dspmath="mathml"><mrow><mi>m</mi><mo>/</mo><mi>z</mi></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="23pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="91270dba487782af7360c80516416e4b"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-21-11505-2021-ie00001.svg" width="23pt" height="14pt" src="acp-21-11505-2021-ie00001.png"/></svg:svg></span></span> 43.018 on the PTR-TOF-MS and was tentatively identified as ketene, a rarely measured reactive volatile organic compound (VOC). Estimated ketene mixing ratios as high as <span class="inline-formula">∼</span> 50 ppb (parts per billion) were observed in the emission plumes. Emission rates of ketene from the facility were estimated using a horizontal advective flux approach and ranged from 84–316 kg h<span class="inline-formula">⁻¹</span>. These emission rates were compared to the emission rates of major known VOCs such as benzene, toluene, and acetaldehyde. Significant correlations (<span class="inline-formula"><i>r</i>²</span> <span class="inline-formula"><i>&gt;</i></span> 0.7) of ketene with methanol, acetaldehyde, benzene, and toluene were observed for the peak emissions, indicating commonality of emission sources. The calculated average ketene OH reactivity for the emission plumes over Daesan ranged from 3.33–7.75 s<span class="inline-formula">⁻¹</span>, indicating the importance of the quantification of ketene to address missing OH reactivity in the polluted environment. The calculated average O<span class="inline-formula">₃</span> production potential for ketene ranged from 2.98–6.91 ppb h<span class="inline-formula">⁻¹</span>. Our study suggests that ketene, or any possible VOC species detected at <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M9" display="inline" overflow="scroll" dspmath="mathml"><mrow><mi>m</mi><mo>/</mo><mi>z</mi></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="23pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="c87305775cdf966f8a4d16ada7bea42b"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-21-11505-2021-ie00002.svg" width="23pt" height="14pt" src="acp-21-11505-2021-ie00002.png"/></svg:svg></span></span> 43.018, has the potential to significantly influence local photochemistry, and therefore, further studies focusing on the photooxidation and atmospheric fate of ketene through chamber studies are required to improve our current understanding of VOC OH reactivity and, hence, tropospheric O<span class="inline-formula">₃</span> production.</p>