Thermal decomposition of toluene and of benzyl radicals in shock waves

Astholz, D. C.; Durant, J. L.; Troe, J.

doi:10.1016/s0082-0784(81)80092-6

Cited by 30 publications

(20 citation statements)

References 17 publications

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“…has been studied in shock tubes by several researchers by UV transient absorption spectroscopy in the spectral region of 190− 330 nm 13,16,17,19,20 and by the atomic resonance absorption spectroscopy (ARAS) of H atoms. 14,18,21 The representative results are summarized and compared in refs 20 and 21.…”

Section: Introductionmentioning

confidence: 99%

Thermal Decomposition of Benzyl Radicals: Kinetics and Spectroscopy in a Shock Tube

Matsugi

2020

J. Phys. Chem. A

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Understanding the mechanism of high-temperature reactions of aromatic hydrocarbons and radicals is essential for the modeling of hydrocarbon growth processes in combustion environments. In this study, the thermal decomposition reaction of benzyl radicals was investigated using time-resolved broadband cavity-enhanced absorption spectroscopy behind reflected shock waves at a postshock pressure of 100 kPa and temperatures of 1530, 1630, and 1740 K. The transient absorption spectra during the decomposition were recorded over the spectral range of 282−410 nm. The spectra were contributed by the absorption of benzyl radicals and some transient and residual absorbing species. The temporal behavior of the absorption was analyzed using a kinetic model to determine the rate constant for benzyl decomposition. The obtained rate constants can be represented by the Arrhenius expression k 1 = 1.1 × 10 12 exp(−30 500 K/T) s −1 with an estimated logarithmic uncertainty of Δlog 10 k = ±0.2. Kinetic simulation of the secondary reactions indicated that fulvenallenyl radicals are potentially responsible for the transient absorption that appeared around 400 nm. This assignment is consistent with the available spectroscopic information of this radical. Possible candidates for the residual absorbing species are presented, suggesting the potential importance of ortho-benzyne as a reactive intermediate.

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Section: Introductionmentioning

confidence: 99%

Thermal Decomposition of Benzyl Radicals: Kinetics and Spectroscopy in a Shock Tube

Matsugi

2020

J. Phys. Chem. A

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“…Future plans to combine toluene with other components will contribute to a better understanding of fuels that are more complex mixtures. Gas-phase toluene pyrolysis has been investigated by several researchers [16][17][18][19], but little is known about the pyrolysis of toluene under supercritical conditions. Likewise, most research on PAH formation pertains to the gas phase [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35]; little has been done under supercritical conditions.…”

Section: Introductionmentioning

confidence: 99%

The effects of pressure on the yields of polycyclic aromatic hydrocarbons produced during the supercritical pyrolysis of toluene

Ledesma

Wornat

Felton

et al. 2005

Proceedings of the Combustion Institute

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“…As seen in Fig. 6, the experimentally measured rate coefficients of the spin-forbidden R 31 (SO 2 (X 1 A 1 ) + O( 3 P) + M → SO 3 (X 1 A 1 ) + M) exhibit an unusual behavior-an increase with temperature (T <∼450 K) [16,17] followed by a sharp decrease with further increase of temperature (T >∼1400 K) [18][19][20]. This unusual behavior of rate coefficients with respect to temperature was first rationalized by Astholz et al [19] in terms of potential energy barrier arising from the triplet-singlet intersystem crossing and diminishing collision efficiency with temperature in the stabilization of the collision complex formed (see the section Discussion for details).…”

Section: Introductionmentioning

confidence: 81%

“…Symbols are as follows: plus, Nettleton and Stirling [45]; open square, Westenberg and deHaas [16]; open triangle up, Astholz et al [18,19]; open triangle right, Atkinson and Pitts [17]; filled triangle left, Merryman and Levy [44]; open diamond, values from the rate coefficient expression of Smith et al [20]; star, Naidoo et al [22]; open circle, this study. Lines are (in cm 6 [18,19] for their RCCSD(T)-cf calculation. Furthermore, while they do a good job of calculating the endothermicity of R −50 and R 56 they may be low for R −47 (see their Table 1).…”

Section: Discussionmentioning

confidence: 98%

Determination of the rate coefficients of the SO₂ + O + M → SO₃ + M reaction

Hwang

Cooke

Witt

et al. 2010

Int J of Chemical Kinetics

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Rate coefficients of the title reaction R 31 (SO 2 + O + M → SO 3 + M) and R 56 (SO 2 + HO 2 → SO 3 + OH), important in the conversion of S(IV) to S(VI), were obtained at T = 970-1150 K and ρ ave = 16.2 μmol cm −3 behind reflected shock waves by a perturbation method. Shockheated H 2 /O 2 /Ar mixtures were perturbed by adding small amounts of SO 2 (1%, 2%, and 3%) and the OH temporal profiles were then measured using laser absorption spectroscopy. Reaction rate coefficients were elucidated by matching the characteristic reaction times acquired from the individual experimental absorption profiles via simultaneous optimization of k 31 and k 56 values in the reaction modeling (for satisfactory matches to the observed characteristic times, it was necessary to take into account R 56 ). In the experimental conditions of this study, R 31 is in the low-pressure limit. The rate coefficient expressions fitted using the combined data of this study and the previous experimental results are k 31,0 /[Ar] = 2.9 × 10 35 T −6.0 exp(−4780 K/T ) + 6.1 × 10 24 T −3.0 exp(−1980 K/T ) cm 6 mol −2 s −1 at T = 300-2500 K; k 56 = 1.36 × 10 11 exp(−3420 K/T ) cm 3 mol −1 s −1 at T = 970-1150 K. Computer simulations of typical aircraft engine environments, using the reaction mechanism with the above k 31,0 and k 56 expressions, gave the maximum S(IV) to S(VI) conversion yield of ca. 3.5% and 2.5% for the constant density and constant pressure flow condition, respectively. Moreover, maximum conversions occur at

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Thermal decomposition of toluene and of benzyl radicals in shock waves

Cited by 30 publications

References 17 publications

Thermal Decomposition of Benzyl Radicals: Kinetics and Spectroscopy in a Shock Tube

Thermal Decomposition of Benzyl Radicals: Kinetics and Spectroscopy in a Shock Tube

The effects of pressure on the yields of polycyclic aromatic hydrocarbons produced during the supercritical pyrolysis of toluene

Determination of the rate coefficients of the SO₂ + O + M → SO₃ + M reaction

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Thermal decomposition of toluene and of benzyl radicals in shock waves

Cited by 30 publications

References 17 publications

Thermal Decomposition of Benzyl Radicals: Kinetics and Spectroscopy in a Shock Tube

Thermal Decomposition of Benzyl Radicals: Kinetics and Spectroscopy in a Shock Tube

The effects of pressure on the yields of polycyclic aromatic hydrocarbons produced during the supercritical pyrolysis of toluene

Determination of the rate coefficients of the SO2 + O + M → SO3 + M reaction

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Determination of the rate coefficients of the SO₂ + O + M → SO₃ + M reaction