Experimental and Numerical Study of Ethyl Valerate Flat Flames at Low Pressure

ABSTRACT

Three flat flames of ethyl valerate (C₇H₁₄O₂) at different equivalence ratios, 0.81, 0.95, and 1.31, have been stabilized at 55 mbar and analyzed using gas chromatography. Based on the experimental results, a detailed kinetic model of ethyl valerate combustion, containing 211 species and 1368 reactions, has been elaborated. The model predictions agree well with the experimental results for the temperature range of 1100–2000 K. In the lean flame, the main decomposition pathways leads to C₇H₁₄O₂ → CH₃(CH₂)₃COOCHCH₃ → CH₃CHO → CH₃CO → CH₃ → CH₂O → HCO. For the stoichiometric flame, the ethyl valerate consumption pathway produces C₇H₁₄O₂ → C₄H₉COOH → CH₃CHCH₂CH₂COOH → C₄H₇COOH → CH₂COOH → CH₂CO → CH₃ → CH₂O → HCO. In the rich flame, from ethyl valerate to pentenoic acid (C₄H₇COOH), the decomposition pathway is the same as in the stoichiometric flame. The pentenoic acid leads to the formation of C₂H₄ via C₄H₆ and C₃H₆. Finally, the new model has been tested on the experimental data obtained in a jet-stirred reactor at high pressure (10 atm) and low temperatures (560–1160 K). The mechanism predicts fairly well all the species, except H₂ and C₂H₂. Future work should improve the mechanism to extend its validity range up to high pressure and low temperature range.

KEYWORDS:

• Ethyl pentanoate
• Ethyl valerate
• Flat flames
• Low pressure

Acknowledgments

The authors wish to thank Région Wallonne (Belgium) for the financial support (Convention No. 1250393). They are also grateful to Prof. Guillaume Dayma (Professor at the Université d’Orléans, France) for helping them in the validation of the mechanism at high pressure. This project is also a part of the IEA (International Energy Agency) Implementing Agreement for Energy Conservation and Emission Reduction in Combustion.