A comprehensive experimental and kinetic modeling study of di-isobutylene isomers: Part 2

Nitin Lokachari (1) , Goutham Kukkadapu (2) , Brian D Etz (3) , Gina M Fioroni (3) , Seonah Kim (3) , Mathias Steglich (4) , Andras Bodi (4) , Patrick Hemberger (4) , Sergey S Matveev , Anna Thomas (3) , Hwasup Song (5, 6) , Guillaume Vanhove (5) , Kuiwen Zhang (2) , Guillaume Dayma (7) , Maxence Lailliau (7) , Zeynep Serinyel (7) , Alexander A Konnov (8) , Philippe Dagaut (7) , William J Pitz (2) , Henry J Curran (1)

1 NUI Galway - National University of Ireland [Galway]
2 LLNL - Lawrence Livermore National Laboratory
3 NREL - National Renewable Energy Laboratory
4 PSI - Paul Scherrer Institute
5 PC2A - Physicochimie des Processus de Combustion et de l’Atmosphère - UMR 8522
6 Kumoh National Institute of Technology [Gumi]
7 ICARE - Institut de Combustion, Aérothermique, Réactivité et Environnement
8 Skane University Hospital [Lund]

A wide variety of high temperature experimental data obtained in this study complement the data on the oxidation of the two di-isobutylene isomers presented in Part I, and offers a basis for an extensive validation of the kinetic model developed in this study. Due to the increasing importance of unimolecular decomposition reactions in high-temperature combustion, we have investigated the di-isobutylene isomers in high dilution utilizing a pyrolysis micro reactor and detected radical intermediates and stable products using vacuum ultraviolet (VUV) synchrotron radiation and photoelectron photoion coincidence (PEPICO) spectroscopy. Additional speciation data at oxidative conditions were also recorcollecdted utilizing a plug flow reactor at atmospheric pressure in the temperature range from 725 K to-1150 K at equivalence ratios of 1.0 and 3.0 and at a residence time of 0.35 s and 0.22 s respectively. Combustion products were analyzed using gas chromatography (GC) and mass spectrometry (MS). Ignition delay time measurements for di-isobutylene were performed at pressures of 15 and 30 bar at equivalence ratios of 0.5, 1.0, and 2.0 diluted in 'air' in the temperature range 900-1400 K using a high-pressure shock-tube facility. New measurements of the laminar burning velocities of di-isobutylene/ + air flames are also presented. Experiments have been performed using the heat flux method at atmospheric pressure and initial temperatures of 298-358 K. Moreover, data consistency was assessed with the help of analysis of the temperature and pressure dependencies of the laminar burning velocity measurements, which was interpreted using an empirical power-law expression. Electronic structure calculations were performed to compute the energy barriers to the formation of many of the product species formed. The predictions of the present mechanism were found to be in good adequate agreement with the wide variety of the experimental measurements performed.

Mots clés: di-isobutylene; pyrolysis; ignition delay; burning velocity; kinetic modeling

Domaines: Chimie théorique et/ou physique; Milieux fluides et réactifs

Nitin Lokachari, Goutham Kukkadapu, Brian D Etz, Gina M Fioroni, Seonah Kim, et al.. A comprehensive experimental and kinetic modeling study of di-isobutylene isomers: Part 2. Combustion and Flame, 2023, 251, pp.112547. ⟨10.1016/j.combustflame.2022.112547⟩. ⟨hal-04523993v1⟩