Flame Experiments at the Advanced Light Source: New Insights into Soot Formation Processes

The following experimental protocols and the accompanying video are concerned with the flame experiments that are performed at the Chemical Dynamics Beamline of the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory(1-4). This video demonstrates how the complex chemical structu...

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Autores principales: Hansen, Nils, Skeen, Scott A., Michelsen, Hope A., Wilson, Kevin R., Kohse-Höinghaus, Katharina
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MyJove Corporation 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4207224/
https://www.ncbi.nlm.nih.gov/pubmed/24894694
http://dx.doi.org/10.3791/51369
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author Hansen, Nils
Skeen, Scott A.
Michelsen, Hope A.
Wilson, Kevin R.
Kohse-Höinghaus, Katharina
author_facet Hansen, Nils
Skeen, Scott A.
Michelsen, Hope A.
Wilson, Kevin R.
Kohse-Höinghaus, Katharina
author_sort Hansen, Nils
collection PubMed
description The following experimental protocols and the accompanying video are concerned with the flame experiments that are performed at the Chemical Dynamics Beamline of the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory(1-4). This video demonstrates how the complex chemical structures of laboratory-based model flames are analyzed using flame-sampling mass spectrometry with tunable synchrotron-generated vacuum-ultraviolet (VUV) radiation. This experimental approach combines isomer-resolving capabilities with high sensitivity and a large dynamic range(5,6). The first part of the video describes experiments involving burner-stabilized, reduced-pressure (20-80 mbar) laminar premixed flames. A small hydrocarbon fuel was used for the selected flame to demonstrate the general experimental approach. It is shown how species’ profiles are acquired as a function of distance from the burner surface and how the tunability of the VUV photon energy is used advantageously to identify many combustion intermediates based on their ionization energies. For example, this technique has been used to study gas-phase aspects of the soot-formation processes, and the video shows how the resonance-stabilized radicals, such as C(3)H(3), C(3)H(5), and i-C(4)H(5), are identified as important intermediates(7). The work has been focused on soot formation processes, and, from the chemical point of view, this process is very intriguing because chemical structures containing millions of carbon atoms are assembled from a fuel molecule possessing only a few carbon atoms in just milliseconds. The second part of the video highlights a new experiment, in which an opposed-flow diffusion flame and synchrotron-based aerosol mass spectrometry are used to study the chemical composition of the combustion-generated soot particles(4). The experimental results indicate that the widely accepted H-abstraction-C(2)H(2)-addition (HACA) mechanism is not the sole molecular growth process responsible for the formation of the observed large polycyclic aromatic hydrocarbons (PAHs).
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spelling pubmed-42072242014-10-24 Flame Experiments at the Advanced Light Source: New Insights into Soot Formation Processes Hansen, Nils Skeen, Scott A. Michelsen, Hope A. Wilson, Kevin R. Kohse-Höinghaus, Katharina J Vis Exp Physics The following experimental protocols and the accompanying video are concerned with the flame experiments that are performed at the Chemical Dynamics Beamline of the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory(1-4). This video demonstrates how the complex chemical structures of laboratory-based model flames are analyzed using flame-sampling mass spectrometry with tunable synchrotron-generated vacuum-ultraviolet (VUV) radiation. This experimental approach combines isomer-resolving capabilities with high sensitivity and a large dynamic range(5,6). The first part of the video describes experiments involving burner-stabilized, reduced-pressure (20-80 mbar) laminar premixed flames. A small hydrocarbon fuel was used for the selected flame to demonstrate the general experimental approach. It is shown how species’ profiles are acquired as a function of distance from the burner surface and how the tunability of the VUV photon energy is used advantageously to identify many combustion intermediates based on their ionization energies. For example, this technique has been used to study gas-phase aspects of the soot-formation processes, and the video shows how the resonance-stabilized radicals, such as C(3)H(3), C(3)H(5), and i-C(4)H(5), are identified as important intermediates(7). The work has been focused on soot formation processes, and, from the chemical point of view, this process is very intriguing because chemical structures containing millions of carbon atoms are assembled from a fuel molecule possessing only a few carbon atoms in just milliseconds. The second part of the video highlights a new experiment, in which an opposed-flow diffusion flame and synchrotron-based aerosol mass spectrometry are used to study the chemical composition of the combustion-generated soot particles(4). The experimental results indicate that the widely accepted H-abstraction-C(2)H(2)-addition (HACA) mechanism is not the sole molecular growth process responsible for the formation of the observed large polycyclic aromatic hydrocarbons (PAHs). MyJove Corporation 2014-05-26 /pmc/articles/PMC4207224/ /pubmed/24894694 http://dx.doi.org/10.3791/51369 Text en Copyright © 2014, Journal of Visualized Experiments http://creativecommons.org/licenses/by-nc-nd/3.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License. To view a copy of this license, visithttp://creativecommons.org/licenses/by-nc-nd/3.0/
spellingShingle Physics
Hansen, Nils
Skeen, Scott A.
Michelsen, Hope A.
Wilson, Kevin R.
Kohse-Höinghaus, Katharina
Flame Experiments at the Advanced Light Source: New Insights into Soot Formation Processes
title Flame Experiments at the Advanced Light Source: New Insights into Soot Formation Processes
title_full Flame Experiments at the Advanced Light Source: New Insights into Soot Formation Processes
title_fullStr Flame Experiments at the Advanced Light Source: New Insights into Soot Formation Processes
title_full_unstemmed Flame Experiments at the Advanced Light Source: New Insights into Soot Formation Processes
title_short Flame Experiments at the Advanced Light Source: New Insights into Soot Formation Processes
title_sort flame experiments at the advanced light source: new insights into soot formation processes
topic Physics
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4207224/
https://www.ncbi.nlm.nih.gov/pubmed/24894694
http://dx.doi.org/10.3791/51369
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