Elsevier

Energy

Volume 215, Part A, 15 January 2021, 119115
Energy

Laminar flame structure of ethyl pentanoate at low and atmospheric-pressure: Experimental and kinetic modeling study

https://doi.org/10.1016/j.energy.2020.119115Get rights and content

Highlights

  • Ethyl pentanoate is a renewable potential fuel for spark ignition engines.

  • Flame structure at low and atmospheric pressure was experimentally examined.

  • The updated chemical kinetic model was developed and validated.

  • The reaction pathways analysis of ethyl pentanoate combustion was carried out.

  • The proposed model is a basis for development of models for biofuels combustion.

Abstract

Ethyl pentanoate (EPE) or ethyl valerate is considered a surrogate for biodiesel fuels and a potential fuel for spark ignition engines. Knowledge of its combustion chemistry is of great importance for the development of high-performance and environmentally friendly combustion devices fueled with biofuels. In this work, a detailed chemical kinetic mechanism for the combustion of EPE is developed on the basis of a well-validated kinetic model proposed earlier for short ethyl esters up to ethyl propionate (by Sun et al.). The Sun et al. mechanism was augmented with primary oxidation reactions of ethyl butanoate and ethyl pentanoate and specific intermediates involved in these reactions. The proposed kinetic mechanism was validated against the new experimental data reported in this work on the chemical speciation of laminar premixed flames of stoichiometric EPE/O2/Ar mixtures at low (50 Torr) and atmospheric pressures. The mechanism provided a good predictive capability for experimental mole fraction profiles of many flame intermediates. The new mechanism was also shown to predict well literature experimental data on laminar flame speeds of EPE/air mixtures in a range of equivalence ratios and pressures. The reported flame data can be used for validation of kinetic models for ethyl ester-based biofuels.

Section snippets

Author contribution

A.M. Dmitriev: Conceptualization, Methodology, Investigation, Data curation, Validation, Visualization, Formal analysis, Writing - original draft, Writing - review & editing, K.N. Osipova: Data curation, Visualization, Formal analysis, A.G. Shmakov: Conceptualization, Methodology, Supervision, T.A. Bolshova: Visualization, Formal analysis, D.A. Knyazkov: Conceptualization, Methodology, Investigation, Writing - original draft, Writing - review & editing, P.A. Glaude: Conceptualization,

Experimental approach

Flame sampling is a challenging task because of the high temperature and species concentration gradients in the flame front. Studies of flame structures at atmospheric and elevated pressures are of high practical importance, however, low-pressure flame structure remains in demand. The main idea of studying low-pressure laminar flames is to stretch the flame zone to improve spatial resolution. In addition, low-pressure conditions significantly reduce the requirements for the pumping system. Both

Low-pressure flame

Low-pressure flat laminar flame of the EPE/O2/Ar mixture was investigated at the LRGP. Mole fraction profiles of 24 individual species were measured using GC analysis. Among them are C1–C4 hydrocarbons, aldehydes, alcohols, ketones, carboxylic acids, and carbon oxides. The species detected and their molecular structures are listed in Table 3.

Experimental and simulated mole fraction profiles of reactants (EPE, O2, Ar) and major flame products (H2, H2O, CO, CO2) are presented in Fig. 2. The

Conclusion

An updated chemical kinetic mechanism for EPE combustion was proposed in this work. The mechanism includes the most recent rate constants of the most important reactions, including their pressure dependencies, and it is certainly able to reproduce the main trends in the combustion kinetics of lighter ethyl esters with an alkyl chain from C0 to C5.

The mechanism was validated against the new experimental data reported in this paper on the chemical speciation of two laminar premixed stoichiometric

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgements

D.A.K. gratefully acknowledges financial support from the Ministry of Science and Higher Education of the Russian Federation (project No075-15-2019-1878).

References (62)

  • L. Gasnot et al.

    Ethyl acetate oxidation in flame condition: an experimental study

    Fuel

    (2004)
  • K.N. Osipova et al.

    Combustion of ethyl acetate: the experimental study of flame structure and validation of chemical kinetic mechanisms

    Mendeleev Commun

    (2019)
  • H. Bennadji et al.

    Experimental and kinetic modeling study of ethyl butanoate oxidation in a laminar tubular plug flow reactor

    Fuel

    (2011)
  • D.A. Knyazkov et al.

    Photoionization mass spectrometry and modeling study of a low-pressure premixed flame of ethyl pentanoate (ethyl valerate)

    Proc Combust Inst

    (2017)
  • Y. Zhang et al.

    Experimental study of the autoignition of C8H16O2 ethyl and methyl esters in a motored engine

    Combust Flame

    (2010)
  • M.K. Ghosh et al.

    The combustion kinetics of the lignocellulosic biofuel, ethyl levulinate

    Combust Flame

    (2018)
  • V. Dias et al.

    The influence of ethanol addition on a rich premixed benzene flame at low pressure

    Combust Flame

    (2014)
  • E. Pousse et al.

    A lean methane premixed laminar flame doped with components of diesel fuel: I. n-Butylbenzene

    Combust Flame

    (2009)
  • L.-S. Tran et al.

    An experimental and modeling study of the combustion of tetrahydrofuran

    Combust Flame

    (2015)
  • I.E. Gerasimov et al.

    Structure of atmospheric-pressure fuel-rich premixed ethylene flame with and without ethanol

    Combust Flame

    (2012)
  • A.M. Dmitriev et al.

    The effect of methyl pentanoate addition on the structure of premixed fuel-rich n-heptane/toluene flame at atmospheric pressure

    Combust Flame

    (2015)
  • T.A. Cool et al.

    Studies of a fuel-rich propane flame with photoionization mass spectrometry

    Proc Combust Inst

    (2005)
  • W.E. Kaskan

    The dependence of flame temperature on mass burning velocity

    Proc Combust Inst

    (1957)
  • Q.-D. Wang et al.

    Theoretical and kinetic study of the hydrogen atom abstraction reactions of ethyl esters with hydrogen radicals

    Chem Phys Lett

    (2014)
  • S. Namysl et al.

    A first evaluation of butanoic and pentanoic acid oxidation kinetics

    Chem Eng J

    (2019)
  • C. Cavallotti et al.

    Analysis of acetic acid gas phase reactivity: rate constant estimation and kinetic simulations

    Proc Combust Inst

    (2019)
  • A.M. Dmitriev et al.

    Structure of CH4/O2/Ar flames at elevated pressures studied by flame sampling molecular beam mass spectrometry and numerical simulation

    Combust Flame

    (2015)
  • D.A. Knyazkov et al.

    Structure of premixed H2/O2/Ar flames at 1–5 atm studied by molecular beam mass spectrometry and numerical simulation

    Proc Combust Inst

    (2017)
  • H.J. Curran

    Developing detailed chemical kinetic mechanisms for fuel combustion

    Proc Combust Inst

    (2019)
  • W.K. Metcalfe et al.

    Experimental and modeling study of C5H10O2 ethyl and methyl esters

    J Phys Chem A

    (2007)
  • M.H. Hakka et al.

    Oxidation of methyl and ethyl butanoates

    Int J Chem Kinet

    (2010)
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