The spin-forbidden dissociation–recombination reaction SO3?SO2+O

Astholz, D. C.; Glänzer, K.; Troe, J.

doi:10.1063/1.437751

Cited by 25 publications

(64 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…From an assessment of each contribution, we estimate the overall uncertainty in k 1b to be a factor of 2. Figure 8 compares the data for the thermal dissociation rate of SO 3 with the only other measurements of this reaction, the shock tube study of Astholz et al 10 While the present study involved nitrogen as collision partner, Astholz et al conducted their experiments in argon. The two sets of data appear to be consistent, but a direct comparison is difficult due to the differences in the temperature regime and bath gas.…”

Section: Resultsmentioning

confidence: 95%

“…14 The results from the flow reactor study of Mueller et al 7 and the shock tube study of Hwang et al 15 on the reaction are not included, since they were obtained at higher pressures. The hightemperature data of Astholz et al 10 and Smith et al 12 are shown, even though they relate to argon as a bath gas. The values of k 1 [ The solid lines are the rate constant at 1 atm, while the dashed lines represent the low-pressure limit.…”

Section: Resultsmentioning

confidence: 99%

“…The product gas from the homogeneous reactor is analyzed. (4)(5)(6)(7)(8)(9)(10) Step 3 is repeated for temperatures of 948, 973, 998, 1023, 1048, 1073, and 1176 K. , from which k 1b can easily be obtained. Since R2 is comparatively fast according to the flame measurements, the inequality is almost fulfilled and the error in the values in k 1b from the simple analysis, compared to the detailed analysis, is only of the order of 30%.…”

Section: Resultsmentioning

confidence: 99%

“…15 The rate constant increases with temperature at lower temperatures, peaks at around 750 K, and drops off as the temperature increases further. 9,10 The positive temperature dependence below 750 K arises from a barrier of about 16 kJ/ mol to reaction, 9 while at higher temperatures the dominant effect becomes the limitations in collisional stabilization of the SO 3 / intermediate, causing a decrease in the reaction rate. A Rice-Ramsperger-Kassel-Marcus (RRKM) extrapolation of the low-temperature measurements is in good agreement with data for both the forward and backward reaction over a temperature range of 220-2500 K for Ar as collision partner.…”

Section: Introductionmentioning

confidence: 99%

“…4,5 Flow reactor studies of SO 2 oxidation under post-flame conditions 5,7 indicate fractional conversions of SO 2 to SO 3 of the order of a few percent. According to these studies, SO 3 formation occurs primarily through the reaction Direct measurements are available for this reaction in the 300-800 K range 8,9 and for the reverse reaction, thermal dissociation of SO 3 , in the temperature range of 1700-2500 K. 10 Indirect determinations are available from flames [12][13][14] and shock tube experiments. 15 The rate constant increases with temperature at lower temperatures, peaks at around 750 K, and drops off as the temperature increases further.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Thermal Dissociation of SO₃ at 1000−1400 K

et al. 2006

View full text Add to dashboard Cite

The thermal dissociation of SO 3 has been studied for the first time in the 1000-1400 K range. The experiments were conducted in a laminar flow reactor at atmospheric pressure, with nitrogen as the bath gas. On the basis of the flow reactor data, a rate constant for SO 3 + N 2 f SO 2 + O + N 2 (R1b) of 5.7 × 10 17 exp(-40000/T) cm 3 /(mol s) is derived for the temperature range 1273-1348 K. The estimated uncertainty is a factor of 2. The rate constant corresponds to a value of the reverse reaction of k 1 ≈ 1.8 × 10 15 cm 6 mol -2 s -1 . The reaction is in the falloff region under the investigated conditions. The temperature and pressure dependence of SO 2 + O (+N 2 ) was estimated from the extrapolation of low temperature results for the reaction, together with an estimated broadening parameter and the high-pressure limit determined recently by Naidoo, Goumri, and Marshall (Proc. Combust. Inst. 2005, 30, 1219-1225. The theoretical rate constant is in good agreement with the experimental results. The improved accuracy in k 1 allows a reassessment of the rate constant for SO 3 + O f SO 2 + O 2 (R2) based on the data of Smith, Tseregounis, and Wang (Int. J. Chem. Kinet. 1982, 14, 679-697), who conducted experiments on a low-pressure CO/O 2 /Ar flame doped with SO 2 . At the location in the flame where the net SO 3 formation rate is zero,A value of 6.9 × 10 10 cm 3 mol -1 s -1 is obtained for k 2 at 1269 K with an uncertainty a factor of 3. A recommended rate constant k 2 ) 7.8 × 10 11 exp(-3065/T) cm 3 mol -1 s -1 is consistent with other flame results as well as the present flow reactor data.

show abstract

Section: Resultsmentioning

confidence: 95%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Thermal Dissociation of SO₃ at 1000−1400 K

et al. 2006

View full text Add to dashboard Cite

show abstract

Impact of SO2 and NO on CO oxidation under post-flame conditions

Glarborg

Kubel

Dam‐Johansen

et al. 1996

Int. J. Chem. Kinet.

141

128

View full text Add to dashboard Cite

An experimental and theoretical study on the effect of SO2 on moist CO oxidation with and without NO present has been carried out. The experiments were performed in an isothermal quartz flow reactor at atmospheric pressure in the temperature range 800–1300 K. Inlet concentrations of SO2 ranged from 0 to 1800 ppmv, while the NO ranged between 0, 100, or 1500 ppm. SO2 inhibits CO oxidation under the conditions investigated, shifting the fast oxidation regime 20–40 K towards higher temperatures at 1500 ppm SO2. The inhibition is most pronounced at high O atom levels. The experimental data supported by model analysis suggest that SO2 primarily reacts with O atoms forming SO3, which is subsequently consumed mainly by reaction with O and HO2. Addition of NO significantly diminishes the effect of SO2. Since NO is usually present in combustion flue gases, the impact of SO2 on CO burnout in most practical systems is projected to be small. The H/S/O thermochemistry and reaction subset has been revised based on recent experimental and theoretical results, and a chemical kinetic model has been established. The model provides a reasonable overall description of the effect of SO2 and NO on moist CO oxidation, while the SO3/SO2 ratio is well predicted over the range of conditions investigated. In order to enhance model performance further, rate constants for a number of SO2 and SO3 reactions need to be determined with higher accuracy. © 1996 John Wiley & Sons, Inc.

show abstract

Kinetic modeling of the CO/H2O/O2/NO/SO2 system: Implications for high-pressure fall-off in the SO2 + O(+M) = SO3(+M) reaction

Mueller

Yetter

Dryer

2000

Int. J. Chem. Kinet.

113

100

View full text Add to dashboard Cite

Flow reactor experiments were performed to study moist CO oxidation in the presence of trace quantities of NO (0-400 ppm) and SO 2 (0-1300 ppm) at pressures and temperatures ranging from 0.5-10.0 atm and 950-1040 K, respectively. Reaction profile measurements of CO, CO 2 , O 2 , NO, NO 2 , SO 2 , and temperature were used to further develop and validate a detailed chemical kinetic reaction mechanism in a manner consistent with previous studies of the CO/H 2 /O 2 /NO X and CO/H 2 O/N 2 O systems. In particular, the experimental data indicate that the spin-forbidden dissociation-recombination reaction between SO 2 and Oatoms is in the fall-off regime at pressures above 1 atm. The inclusion of a pressure-dependent rate constant for this reaction, using a high-pressure limit determined from modeling the consumption of SO 2 in a N 2 O/SO 2 /N 2 mixture at 10.0 atm and 1000 K, brings model predictions into much better agreement with experimentally measured CO profiles over the entire pressure range. Kinetic coupling of NO X and SO X chemistry via the radical pool significantly reduces the ability of SO 2 to inhibit oxidative processes. Measurements of SO 2 indicate fractional conversions of SO 2 to SO 3 on the order of a few percent, in good agreement with previous measurements at atmospheric pressure. Modeling results suggest that, at low pressures, SO 3 formation occurs primarily through SO 2 ϩ O(ϩM) ϭ SO 3 (ϩM), but at higher pressures where the fractional conversion of NO to NO 2 increases, SO 3 formation via SO 2 ϩ NO 2 ϭ SO 3 ϩ NO becomes important. For the conditions explored in this study, the primary consumption pathways for SO 3 appear to be SO 3 ϩ HO 2 ϭ HOSO 2 ϩ O 2 and SO 3 ϩ H ϭ SO 2 ϩ OH. Further study of these reactions would increase the confidence with which model predictions of SO 3 can be viewed.

show abstract

The spin-forbidden dissociation–recombination reaction SO3?SO2+O

Cited by 25 publications

References 14 publications

Thermal Dissociation of SO₃ at 1000−1400 K

Thermal Dissociation of SO₃ at 1000−1400 K

Impact of SO2 and NO on CO oxidation under post-flame conditions

Kinetic modeling of the CO/H2O/O2/NO/SO2 system: Implications for high-pressure fall-off in the SO2 + O(+M) = SO3(+M) reaction

Contact Info

Product

Resources

About

The spin-forbidden dissociation–recombination reaction SO3?SO2+O

Cited by 25 publications

References 14 publications

Thermal Dissociation of SO3 at 1000−1400 K

Thermal Dissociation of SO3 at 1000−1400 K

Impact of SO2 and NO on CO oxidation under post-flame conditions

Kinetic modeling of the CO/H2O/O2/NO/SO2 system: Implications for high-pressure fall-off in the SO2 + O(+M) = SO3(+M) reaction

Contact Info

Product

Resources

About

Thermal Dissociation of SO₃ at 1000−1400 K

Thermal Dissociation of SO₃ at 1000−1400 K