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Title: Formation and emission of large furans and oxygenated hydrocarbons from flames

Abstract

Many oxygenated hydrocarbon species formed during combustion, such as furans, are highly toxic and detrimental to human health and the environment. These species may also increase the hygroscopicity of soot and strongly influence the effects of soot on regional and global climate. However, large furans and associated oxygenated species have not previously been observed in flames, and their formation mechanism and interplay with polycyclic aromatic hydrocarbons (PAHs) are poorly understood. We report on a synergistic computational and experimental effort that elucidates the formation of oxygen-embedded compounds, such as furans and other oxygenated hydrocarbons, during the combustion of hydrocarbon fuels. We used ab initio and probabilistic computational techniques to identify low-barrier reaction mechanisms for the formation of large furans and other oxygenated hydrocarbons. We used vacuum-UV photoionization aerosol mass spectrometry and X-ray photoelectron spectroscopy to confirm these predictions. We show that fura ns are produced in the high- Temperature regions of hydrocarbon flames, where they remarkably survive and become the main functional group of oxygenates that incorporate into incipient soot. In controlled flame studies, we discovered ~100 oxygenated species previously unaccounted for. We found that large alcohols and enols act as precursors to furans, leading to incorporation of oxygen into themore » carbon skeletons of PAHs. Our results depart dramatically from the crude chemistry of carbonand oxygen-containing molecules previously considered in hydrocarbon formation and oxidation models and spearhead the emerging understanding of the oxidation chemistry that is critical, for example, to control emissions of toxic and carcinogenic combustion by-products, which also greatly affect global warming.« less

Authors:
 [1];  [2];  [3];  [4];  [1];  [1];  [5];  [6];  [6];  [7];  [1]
  1. Sandia National Lab. (SNL-CA), Livermore, CA (United States). Combustion Research Facility
  2. Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Mechanical Engineering
  3. Stanford Univ., CA (United States). Dept. of Materials Science & Engineering
  4. Sandia National Lab. (SNL-CA), Livermore, CA (United States). Materials Physics Dept.
  5. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Chemical Sciences Division; Univ. of California, Berkeley, CA (United States). Dept. of Chemistry
  6. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Chemical Sciences Division
  7. Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Mechanical Engineering; Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Chemical Engineering; Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Macromolecular Science and Engineering and Biophysics Program
Publication Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
1260993
Grant/Contract Number:
AC02-05CH11231; AC04-94AL85000; SC0002619
Resource Type:
Journal Article: Published Article
Journal Name:
Proceedings of the National Academy of Sciences of the United States of America
Additional Journal Information:
Journal Volume: 113; Journal Issue: 30; Journal ID: ISSN 0027-8424
Publisher:
National Academy of Sciences, Washington, DC (United States)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; furans; oxygenated hydrocarbons; soot; organic carbon; black carbon

Citation Formats

Johansson, K. Olof, Dillstrom, Tyler, Monti, Matteo, El Gabaly, Farid, Campbell, Matthew F., Schrader, Paul E., Popolan-Vaida, Denisia M., Richards-Henderson, Nicole K., Wilson, Kevin R., Violi, Angela, and Michelsen, Hope A. Formation and emission of large furans and oxygenated hydrocarbons from flames. United States: N. p., 2016. Web. doi:10.1073/pnas.1604772113.
Johansson, K. Olof, Dillstrom, Tyler, Monti, Matteo, El Gabaly, Farid, Campbell, Matthew F., Schrader, Paul E., Popolan-Vaida, Denisia M., Richards-Henderson, Nicole K., Wilson, Kevin R., Violi, Angela, & Michelsen, Hope A. Formation and emission of large furans and oxygenated hydrocarbons from flames. United States. doi:10.1073/pnas.1604772113.
Johansson, K. Olof, Dillstrom, Tyler, Monti, Matteo, El Gabaly, Farid, Campbell, Matthew F., Schrader, Paul E., Popolan-Vaida, Denisia M., Richards-Henderson, Nicole K., Wilson, Kevin R., Violi, Angela, and Michelsen, Hope A. 2016. "Formation and emission of large furans and oxygenated hydrocarbons from flames". United States. doi:10.1073/pnas.1604772113.
@article{osti_1260993,
title = {Formation and emission of large furans and oxygenated hydrocarbons from flames},
author = {Johansson, K. Olof and Dillstrom, Tyler and Monti, Matteo and El Gabaly, Farid and Campbell, Matthew F. and Schrader, Paul E. and Popolan-Vaida, Denisia M. and Richards-Henderson, Nicole K. and Wilson, Kevin R. and Violi, Angela and Michelsen, Hope A.},
abstractNote = {Many oxygenated hydrocarbon species formed during combustion, such as furans, are highly toxic and detrimental to human health and the environment. These species may also increase the hygroscopicity of soot and strongly influence the effects of soot on regional and global climate. However, large furans and associated oxygenated species have not previously been observed in flames, and their formation mechanism and interplay with polycyclic aromatic hydrocarbons (PAHs) are poorly understood. We report on a synergistic computational and experimental effort that elucidates the formation of oxygen-embedded compounds, such as furans and other oxygenated hydrocarbons, during the combustion of hydrocarbon fuels. We used ab initio and probabilistic computational techniques to identify low-barrier reaction mechanisms for the formation of large furans and other oxygenated hydrocarbons. We used vacuum-UV photoionization aerosol mass spectrometry and X-ray photoelectron spectroscopy to confirm these predictions. We show that fura ns are produced in the high- Temperature regions of hydrocarbon flames, where they remarkably survive and become the main functional group of oxygenates that incorporate into incipient soot. In controlled flame studies, we discovered ~100 oxygenated species previously unaccounted for. We found that large alcohols and enols act as precursors to furans, leading to incorporation of oxygen into the carbon skeletons of PAHs. Our results depart dramatically from the crude chemistry of carbonand oxygen-containing molecules previously considered in hydrocarbon formation and oxidation models and spearhead the emerging understanding of the oxidation chemistry that is critical, for example, to control emissions of toxic and carcinogenic combustion by-products, which also greatly affect global warming.},
doi = {10.1073/pnas.1604772113},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
number = 30,
volume = 113,
place = {United States},
year = 2016,
month = 7
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1073/pnas.1604772113

Citation Metrics:
Cited by: 3works
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  • Many oxygenated hydrocarbon species formed during combustion, such as furans, are highly toxic and detrimental to human health and the environment. These species may also increase the hygroscopicity of soot and strongly influence the effects of soot on regional and global climate. However, large furans and associated oxygenated species have not previously been observed in flames, and their formation mechanism and interplay with polycyclic aromatic hydrocarbons (PAHs) are poorly understood. We report on a synergistic computational and experimental effort that elucidates the formation of oxygen-embedded compounds, such as furans and other oxygenated hydrocarbons, during the combustion of hydrocarbon fuels. Wemore » used ab initio and probabilistic computational techniques to identify low-barrier reaction mechanisms for the formation of large furans and other oxygenated hydrocarbons. We used vacuum-UV photoionization aerosol mass spectrometry and X-ray photoelectron spectroscopy to confirm these predictions. We show that fura ns are produced in the high- Temperature regions of hydrocarbon flames, where they remarkably survive and become the main functional group of oxygenates that incorporate into incipient soot. In controlled flame studies, we discovered ~100 oxygenated species previously unaccounted for. We found that large alcohols and enols act as precursors to furans, leading to incorporation of oxygen into the carbon skeletons of PAHs. Our results depart dramatically from the crude chemistry of carbonand oxygen-containing molecules previously considered in hydrocarbon formation and oxidation models and spearhead the emerging understanding of the oxidation chemistry that is critical, for example, to control emissions of toxic and carcinogenic combustion by-products, which also greatly affect global warming.« less
  • Direct sampling and GC/MS analysis of fuel-rich, laminar, premixed flames of methane indicates the production of higher in-flame peak concentrations of benzene and polycyclic aromatic hydrocarbons (PAH) than in the flames of ethane under similar combustion conditions. These findings are surprising and significant because the methane flame not only had a higher H/C ratio and lower carbon density, but also produced less acetylene and soot than the ethane flame. These results suggest the significance of species containing an odd number of carbon atoms in PAH formation processes in the methane flame, as well as the importance of soot surface reactions.more » Although aromatic and polyaromatic intermediates constitute trace by-products of combustion, their formation is of practical concern due to their potential adverse health effects.« less
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