Numerical simulations of yield-based sooting tendencies of aromatic fuels using ReaxFF molecular dynamics

doi:10.1016/j.fuel.2019.116545

This content will become publicly available on November 8, 2020

Title: Numerical simulations of yield-based sooting tendencies of aromatic fuels using ReaxFF molecular dynamics

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Abstract

In this work, we present the first ReaxFF Molecular Dynamics (MD) simulations to quantitatively predict the sooting tendencies of various fuels. The specific sooting tendency metric used in this work is the Yield Sooting Index (YSI), which quantifies the effects of fuel molecular structure on soot yield. YSI has been experimentally measured and numerically simulated using computational fluid dynamics for a large range of fuels, but there is no existing reactive MD framework for YSI simulations. To adopt the experimental YSI concept, a multi-stage simulation procedure is designed using ReaxFF. As a proof-of-concept, toluene and phenol are selected as test fuels, since both have relatively well-understood reaction pathways. The ReaxFF YSI simulations are shown to capture key reaction events for both fuels selected that are consistent with existing chemical kinetic understanding. Toluene is shown to mostly retain its original aromatic ring structure and directly grow to larger aromatic compounds with multiple rings. On the other hand, the aromatic growth process from phenol is accompanied by carbon-loss reactions with CO release. In addition, a quantitative YSI formulation is also derived in ReaxFF and the ReaxFF-predicted YSI values are compared with measurement data and reasonably good agreement is achieved. The results reportedmore »« less

Authors:

^[1]; Shabnam, Sharmin ^[2]; van Duin, Adri C. T. ^[2];

^[2]

Pennsylvania State Univ., University Park, PA (United States). Dept. of Chemical Engineering
Pennsylvania State Univ., University Park, PA (United States). Dept. of Mechanical Engineering

Publication Date:: 2019-11-08

Research Org.:: Univ. of Virginia, Charlottesville, VA (United States)

Sponsoring Org.:: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Vehicle Technologies Office (EE-3V)

OSTI Identifier:: 1574238

Grant/Contract Number:: EE0008195

Resource Type:: Accepted Manuscript

Journal Name:: Fuel

Additional Journal Information:: Journal Name: Fuel; Journal ID: ISSN 0016-2361

Publisher:: Elsevier

Country of Publication:: United States

Language:: English

Subject:: reactive molecular dynamics; ReaxFF; sooting tendency; yield sooting index

Citation Formats


                    Kwon, Hyunguk, Shabnam, Sharmin, van Duin, Adri C. T., and Xuan, Yuan. Numerical simulations of yield-based sooting tendencies of aromatic fuels using ReaxFF molecular dynamics.  United States: N. p., 2019. 
        Web.  doi:10.1016/j.fuel.2019.116545.

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                    Kwon, Hyunguk, Shabnam, Sharmin, van Duin, Adri C. T., & Xuan, Yuan. Numerical simulations of yield-based sooting tendencies of aromatic fuels using ReaxFF molecular dynamics.  United States.  doi:10.1016/j.fuel.2019.116545.

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                    Kwon, Hyunguk, Shabnam, Sharmin, van Duin, Adri C. T., and Xuan, Yuan. Fri .  
        "Numerical simulations of yield-based sooting tendencies of aromatic fuels using ReaxFF molecular dynamics".  United States.  doi:10.1016/j.fuel.2019.116545.

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@article{osti_1574238,

  title        = {Numerical simulations of yield-based sooting tendencies of aromatic fuels using ReaxFF molecular dynamics},

  author       = {Kwon, Hyunguk and Shabnam, Sharmin and van Duin, Adri C. T. and Xuan, Yuan},

  abstractNote = {In this work, we present the first ReaxFF Molecular Dynamics (MD) simulations to quantitatively predict the sooting tendencies of various fuels. The specific sooting tendency metric used in this work is the Yield Sooting Index (YSI), which quantifies the effects of fuel molecular structure on soot yield. YSI has been experimentally measured and numerically simulated using computational fluid dynamics for a large range of fuels, but there is no existing reactive MD framework for YSI simulations. To adopt the experimental YSI concept, a multi-stage simulation procedure is designed using ReaxFF. As a proof-of-concept, toluene and phenol are selected as test fuels, since both have relatively well-understood reaction pathways. The ReaxFF YSI simulations are shown to capture key reaction events for both fuels selected that are consistent with existing chemical kinetic understanding. Toluene is shown to mostly retain its original aromatic ring structure and directly grow to larger aromatic compounds with multiple rings. On the other hand, the aromatic growth process from phenol is accompanied by carbon-loss reactions with CO release. In addition, a quantitative YSI formulation is also derived in ReaxFF and the ReaxFF-predicted YSI values are compared with measurement data and reasonably good agreement is achieved. The results reported in this work demonstrates that the ReaxFF-based framework can potentially be used to quantitatively predict the relative sooting tendencies, especially for fuels with unknown or poorly-known chemistry, to understand their sooting properties and in search for soot relevant reaction pathways from these fuels.},

  doi          = {10.1016/j.fuel.2019.116545},

  journal      = {Fuel},

  number       = ,

  volume       = ,

  place        = {United States},

  year         = {2019},

  month        = {11}

}

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