PAH growth initiated by propargyl addition: Mechanism development and computational kinetics

dc.contributor.authorRaj, Abhijeet Dhayal
dc.contributor.authorRachidi, Mariam El
dc.contributor.authorChung, Suk Ho
dc.contributor.authorSarathy, Mani
dc.contributor.departmentChemical Engineering Program
dc.contributor.departmentClean Combustion Research Center
dc.contributor.departmentCombustion and Laser Diagnostics Laboratory
dc.contributor.departmentCombustion and Pyrolysis Chemistry (CPC) Group
dc.contributor.departmentMechanical Engineering Program
dc.contributor.departmentPhysical Science and Engineering (PSE) Division
dc.contributor.institutionDepartment of Chemical Engineering, Petroleum Institute, Abu Dhabi, United Arab Emirates
dc.date.accessioned2015-08-03T11:53:11Z
dc.date.available2015-08-03T11:53:11Z
dc.date.issued2014-04-15
dc.date.published-online2014-04-15
dc.date.published-print2014-04-24
dc.description.abstractPolycyclic aromatic hydrocarbon (PAH) growth is known to be the principal pathway to soot formation during fuel combustion, as such, a physical understanding of the PAH growth mechanism is needed to effectively assess, predict, and control soot formation in flames. Although the hydrogen abstraction C2H2 addition (HACA) mechanism is believed to be the main contributor to PAH growth, it has been shown to under-predict some of the experimental data on PAHs and soot concentrations in flames. This article presents a submechanism of PAH growth that is initiated by propargyl (C 3H3) addition onto naphthalene (A2) and the naphthyl radical. C3H3 has been chosen since it is known to be a precursor of benzene in combustion and has appreciable concentrations in flames. This mechanism has been developed up to the formation of pyrene (A4), and the temperature-dependent kinetics of each elementary reaction has been determined using density functional theory (DFT) computations at the B3LYP/6-311++G(d,p) level of theory and transition state theory (TST). H-abstraction, H-addition, H-migration, β-scission, and intramolecular addition reactions have been taken into account. The energy barriers of the two main pathways (H-abstraction and H-addition) were found to be relatively small if not negative, whereas the energy barriers of the other pathways were in the range of (6-89 kcal·mol-1). The rates reported in this study may be extrapolated to larger PAH molecules that have a zigzag site similar to that in naphthalene, and the mechanism presented herein may be used as a complement to the HACA mechanism to improve prediction of PAH and soot formation. © 2014 American Chemical Society.
dc.description.sponsorshipKAUST CCRC is grateful to Saudi Aramco for sponsoring this research.
dc.identifier.citationRaj, A., Al Rashidi, M. J., Chung, S. H., & Sarathy, S. M. (2014). PAH Growth Initiated by Propargyl Addition: Mechanism Development and Computational Kinetics. The Journal of Physical Chemistry A, 118(16), 2865–2885. doi:10.1021/jp410704b
dc.identifier.doi10.1021/jp410704b
dc.identifier.issn10895639
dc.identifier.journalThe Journal of Physical Chemistry A
dc.identifier.urihttp://hdl.handle.net/10754/563508
dc.publisherAmerican Chemical Society (ACS)
dc.titlePAH growth initiated by propargyl addition: Mechanism development and computational kinetics
dc.typeArticle
display.details.left<span><h5>Type</h5>Article<br><br><h5>Authors</h5><a href="https://repository.kaust.edu.sa/search?spc.sf=dc.date.issued&spc.sd=DESC&f.author=Raj, Abhijeet Dhayal,equals">Raj, Abhijeet Dhayal</a><br><a href="https://repository.kaust.edu.sa/search?query=orcid.id:0000-0001-7392-6777&spc.sf=dc.date.issued&spc.sd=DESC">Rachidi, Mariam El</a> <a href="https://orcid.org/0000-0001-7392-6777" target="_blank"><img src="https://repository.kaust.edu.sa/server/api/core/bitstreams/82a625b4-ed4b-40c8-865a-d6a5225a26a4/content" width="16" height="16"/></a><br><a href="https://repository.kaust.edu.sa/search?query=orcid.id:0000-0001-8782-312X&spc.sf=dc.date.issued&spc.sd=DESC">Chung, Suk Ho</a> <a href="https://orcid.org/0000-0001-8782-312X" target="_blank"><img src="https://repository.kaust.edu.sa/server/api/core/bitstreams/82a625b4-ed4b-40c8-865a-d6a5225a26a4/content" width="16" height="16"/></a><br><a href="https://repository.kaust.edu.sa/search?query=orcid.id:0000-0002-3975-6206&spc.sf=dc.date.issued&spc.sd=DESC">Sarathy, Mani</a> <a href="https://orcid.org/0000-0002-3975-6206" target="_blank"><img src="https://repository.kaust.edu.sa/server/api/core/bitstreams/82a625b4-ed4b-40c8-865a-d6a5225a26a4/content" width="16" height="16"/></a><br><br><h5>KAUST Department</h5><a href="https://repository.kaust.edu.sa/search?spc.sf=dc.date.issued&spc.sd=DESC&f.department=Chemical Engineering Program,equals">Chemical Engineering Program</a><br><a href="https://repository.kaust.edu.sa/search?spc.sf=dc.date.issued&spc.sd=DESC&f.department=Clean Combustion Research Center,equals">Clean Combustion Research Center</a><br><a href="https://repository.kaust.edu.sa/search?spc.sf=dc.date.issued&spc.sd=DESC&f.department=Combustion and Laser Diagnostics Laboratory,equals">Combustion and Laser Diagnostics Laboratory</a><br><a href="https://repository.kaust.edu.sa/search?spc.sf=dc.date.issued&spc.sd=DESC&f.department=Combustion and Pyrolysis Chemistry (CPC) Group,equals">Combustion and Pyrolysis Chemistry (CPC) Group</a><br><a href="https://repository.kaust.edu.sa/search?spc.sf=dc.date.issued&spc.sd=DESC&f.department=Mechanical Engineering Program,equals">Mechanical Engineering Program</a><br><a href="https://repository.kaust.edu.sa/search?spc.sf=dc.date.issued&spc.sd=DESC&f.department=Physical Science and Engineering (PSE) Division,equals">Physical Science and Engineering (PSE) Division</a><br><br><h5>Online Publication Date</h5>2014-04-15<br><br><h5>Print Publication Date</h5>2014-04-24<br><br><h5>Date</h5>2014-04-15</span>
display.details.right<span><h5>Abstract</h5>Polycyclic aromatic hydrocarbon (PAH) growth is known to be the principal pathway to soot formation during fuel combustion, as such, a physical understanding of the PAH growth mechanism is needed to effectively assess, predict, and control soot formation in flames. Although the hydrogen abstraction C2H2 addition (HACA) mechanism is believed to be the main contributor to PAH growth, it has been shown to under-predict some of the experimental data on PAHs and soot concentrations in flames. This article presents a submechanism of PAH growth that is initiated by propargyl (C 3H3) addition onto naphthalene (A2) and the naphthyl radical. C3H3 has been chosen since it is known to be a precursor of benzene in combustion and has appreciable concentrations in flames. This mechanism has been developed up to the formation of pyrene (A4), and the temperature-dependent kinetics of each elementary reaction has been determined using density functional theory (DFT) computations at the B3LYP/6-311++G(d,p) level of theory and transition state theory (TST). H-abstraction, H-addition, H-migration, β-scission, and intramolecular addition reactions have been taken into account. The energy barriers of the two main pathways (H-abstraction and H-addition) were found to be relatively small if not negative, whereas the energy barriers of the other pathways were in the range of (6-89 kcal·mol-1). The rates reported in this study may be extrapolated to larger PAH molecules that have a zigzag site similar to that in naphthalene, and the mechanism presented herein may be used as a complement to the HACA mechanism to improve prediction of PAH and soot formation. © 2014 American Chemical Society.<br><br><h5>Citation</h5>Raj, A., Al Rashidi, M. J., Chung, S. H., & Sarathy, S. M. (2014). PAH Growth Initiated by Propargyl Addition: Mechanism Development and Computational Kinetics. The Journal of Physical Chemistry A, 118(16), 2865–2885. doi:10.1021/jp410704b<br><br><h5>Acknowledgements</h5>KAUST CCRC is grateful to Saudi Aramco for sponsoring this research.<br><br><h5>Publisher</h5><a href="https://repository.kaust.edu.sa/search?spc.sf=dc.date.issued&spc.sd=DESC&f.publisher=American Chemical Society (ACS),equals">American Chemical Society (ACS)</a><br><br><h5>Journal</h5><a href="https://repository.kaust.edu.sa/search?spc.sf=dc.date.issued&spc.sd=DESC&f.journal=The Journal of Physical Chemistry A,equals">The Journal of Physical Chemistry A</a><br><br><h5>DOI</h5><a href="https://doi.org/10.1021/jp410704b">10.1021/jp410704b</a></span>
kaust.personChung, Suk Ho
kaust.personSarathy, Mani
kaust.personRachidi, Mariam El
orcid.authorRaj, Abhijeet Dhayal
orcid.authorRachidi, Mariam El::0000-0001-7392-6777
orcid.authorChung, Suk Ho::0000-0001-8782-312X
orcid.authorSarathy, Mani::0000-0002-3975-6206
orcid.id0000-0002-3975-6206
orcid.id0000-0001-8782-312X
orcid.id0000-0001-7392-6777
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