An Investigation of the Methanol Decomposition Behind Incident Shock Waves

Dombrowsky, Ch.; Hoffmann, A.; Klatt, M.; Wagner, H. Gg.

doi:10.1002/bbpc.19910951217

Cited by 29 publications

(32 citation statements)

References 18 publications

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“…In the gas phase, the decomposition of CH 3 OH has been studied extensively, whereby the excited CH 3 OH has been produced thermally in shock waves and flames, or chemically in the combination reaction CH 3 + OH, or in other chemical reactions like O( 1 D) + CH 4 [2], or CH 2 (ã) + H 2 O [3]. For the gas phase at low densities the decomposition into two radicals CH 3 OH → CH 3 + OH is well accepted as the dominant initial step [4] which proceeds with an activation energy of E A = 334 kJ/mol [5]. This might be different at liquid-like densities realized in supercritical water and it seems to be interesting to study the CH 3 OH and C 2 H 5 OH decomposition under these conditions.…”

Section: Introductionmentioning

confidence: 99%

Methanol and Ethanol Decomposition in Supercritical Water

Hack¹,

Masten²,

Buelow³

2005

Zeitschrift Für Physikalische Chemie

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The decomposition of CH 3 OH and C 2 H 5 OH in supercritical water was studied in a flow reactor tube (Ni/Mo/Cr/Fe alloy) in the temperature range 597 ≤ T/K ≤ 797 at a pressure of p = 315 bar for technical application of scH 2 O for hazardous chemical waste destruction. The CH 3 OH and C 2 H 5 OH concentrations in the liquid as a function of the residence times were determined by a Raman spectrometer. The [CH 3 OH] and [C 2 H 5 OH] resp. decay followed first order kinetics and a rate constant k 1 (653 K) = 1.3 × 10 −2 s −1 for CH 3 OH and k 2 (653 K) = 5.5 × 10 −2 s −1 for C 2 H 5 OH was determined. The rate constant k 1 was found to be independent of the initial CH 3 OH concentration in the mass fraction range 0.002 ≤ x m ≤ 0.04. The rate depended on the history of the reactor. Treatment with NH 4 OH, C 2 H 5 OH or with H 2 O 2 at T = 653 K, did not change the rate. Treatment with HNO 3 /H 2 O 2 , however, at T = 838 K reduced the rate by about a factor of 1000. The Arrhenius-activation energy over the above temperature range was determined to be E A = 164 kJ/mol for methanol and E A = 145 kJ/mol for ethanol. The major products from methanol decomposition were CH 4 , H 2 , and CO 2 as observed by gas chromatography and CH 4 and CO 2 by FTIR-spectrometry. No other products were found. The products were not effected by the pretreatment of the reactor wall. A non-radical mechanism, which explains the formation of only these products, will be discussed.

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Section: Introductionmentioning

confidence: 99%

Methanol and Ethanol Decomposition in Supercritical Water

Hack¹,

Masten²,

Buelow³

2005

Zeitschrift Für Physikalische Chemie

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“…Besides the O( 1 D) + H 2 O(X̃ 1 A 1 ) → OH( 2 Π) + OH( 2 Π) reaction, the reaction O( 1 D) + CH 4 (X̃ 1 A 1 ) is an important source of OH radicals in the stratosphere 2b. The high reactivity of the latter one has been attributed to the possibility for the two singlet reagents to correlate with the singlet ground state (X̃ 1 A) of the CH 3 OH ⧧ reaction intermediate which can be formed via insertion of O( 1 D) into the C−H bond: The unimolecular decomposition of CH 3 OH(X̃ 1 A), which plays an important role in combustion chemistry, has been studied both theoretically and experimentally behind incident shock waves in the temperature range 1400−2200 K and after infrared multiple photon 10a and UV-laser photoexcitation at 193 nm. 10b,c …”

Section: Introductionmentioning

confidence: 99%

Absolute Reactive Cross Section for H Atom Formation in the Reaction of Translationally Energetic O(¹D) Atoms with Methane

et al. 1998

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The dynamics of the H atom formation channel in the reaction of metastable oxygen atoms O(1D) with methane were studied in the gas phase using the pulsed laser photolysis/vacuum-UV laser-induced fluorescence “pump-and-probe” technique. Translationally energetic O(1D) atoms with an average collision energy of 37 kJ/mol in the O(1D)−CH4 center-of-mass system were generated by laser photolysis of N2O at 193 nm. Nascent H atoms produced in reactive collisions of O(1D) with room-temperature CH4 molecules were detected with sub-Doppler resolution via (2p2P ← 1s2S) laser-induced fluorescence. An absolute reaction cross section of σH(37 kJ/mol) = 1.4 ± 0.5 Å2 was determined for the H atom formation channel by means of a calibration method. From the H atom Doppler profiles measured under single-collision conditions the product translational energy release was determined.

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“…Chúng gần như không bị phân hủy khi ở nhiệt độ cao, đây là điểm khác biệt so với các gốc ankyl khác [1,2]. Metanol (CH3OH) có thể được sử dụng như một loại nhiên liệu thay thế có tác động gây ô nhiễm thấp hơn so với các nguồn nhiên liệu phổ biến hiện nay và có thể được sản xuất từ con đường sinh hóa vì vậy các phản ứng của metanol được nghiên cứu rất rộng rãi [3][4][5][6]. Phản ứng của gốc ________  Tác giả liên hệ.…”

Section: đặT Vấn đề unclassified

Kinetics of the Reaction of Methyl Radical with Methanol

Tho

Sang²

2018

NST

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This work studied theoretically in details the mechanism, kinetics and thermochemistry of reactions of methyl radical with methanol. The theoretical study was carried out by ab initio molecular orbital theory based on CCSD(T)/B3LYP/6-311++G(3df,2p) methods in conjunction variational transition state theory (VTST). Calculated results showed that, in the temperature range from 300K to 2000K, and the pressure at 760 Torr, temperature dependent rate constants of the reactions were: CH3 + CH3OH ® CH4 + CH2OH k(T) = 2.146´10-27.T4.64.exp(-33.47[kJ/mol/RT), CH3 + CH3OH ® CH4 + CH3O k(T) = 2.583´10-27.T4.52.exp(-29.56[kJ/mol/RT), CH3 + CH3OH ® H + CH3OCH3 k(T) = 1.025´10-23.T3.16.exp(-186.84[kJ/mol/RT) When the reaction temperature is above 730 K, the abstraction process of H in –CH3 group of methanol will occur faster. The abstraction process of H in –OH group dominates when the reaction temperature is below 730 K. Keywords Kinetic, methyl, methanol, ab initio References 1. Slagle, I.R., D. Sarzynski, and D. Gutman, Kinetics of the reaction between methyl radicals and oxygen atoms between 294 and 900 K. The Journal of Physical Chemistry, 1987. 91(16): p. 4375-4379.2. Rutz L., B.H., Bozzelli J. W., Methyl Radical and Shift Reactions with Aliphatic and Aromatic Hydrocarbons: Thermochemical Properties, Reaction Paths and Kinetic Parameters. American Chemical Society, Division Fuel Chemistry, 2004. 49(1): p. 451-452.3. Johnson, D.G., M.A. Blitz, and P.W. Seakins, The reaction of methylidene (CH) with methanol isotopomers. Physical Chemistry Chemical Physics, 2000. 2(11): p. 2549-2553.4. Cribb, P.H., J.E. Dove, and S. Yamazaki, A kinetic study of the pyrolysis of methanol using shock tube and computer simulation techniques. Combustion and Flame, 1992. 88(2): p. 169-185.5. Dombrowsky, C., et al., An Investigation of the Methanol Decomposition Behind Incident Shock Waves. Berichte der Bunsengesellschaft für physikalische Chemie, 1991. 95(12): p. 1685-1687.6. Krasnoperov, L.N. and J.V. Michael, High-Temperature Shock Tube Studies Using Multipass Absorption: Rate Constant Results for OH + CH3, OH + CH2, and the Dissociation of CH3OH. The Journal of Physical Chemistry A, 2004. 108(40): p. 8317-8323.7. Shannon, T.W. and A.G. Harrison, The reaction of methyl radicals with methyl alcohol. Canadian Journal of Chemistry, 1963. 41(10): p. 2455-2461.8. Jodkowski, J.T., et al., Theoretical Study of the Kinetics of the Hydrogen Abstraction from Methanol. 3. Reaction of Methanol with Hydrogen Atom, Methyl, and Hydroxyl Radicals. The Journal of Physical Chemistry A, 1999. 103(19): p. 3750-3765.9. Alecu, I.M. and D.G. Truhlar, Computational Study of the Reactions of Methanol with the Hydroperoxyl and Methyl Radicals. 2. Accurate Thermal Rate Constants. The Journal of Physical Chemistry A, 2011. 115(51): p. 14599-14611.10. Peukert, S.L. and J.V. Michael, High-Temperature Shock Tube and Modeling Studies on the Reactions of Methanol with D-Atoms and CH3-Radicals. The Journal of Physical Chemistry A, 2013. 117(40): p. 10186-10195.11. Anastasi, C. and D.U. Hancock, Reaction of CH3 radicals with methanol in the range 525 <T/K < 603. Journal of the Chemical Society, Faraday Transactions, 1990. 86(14): p. 2553-2555.12. Dombrowsky, C. and H.G. Wagner, An investigation of the reaction between CH3 radicals and methanol at high temperatures. Berichte der Bunsengesellschaft für physikalische Chemie, 1989. 93(5): p. 633-637.13. Tsang, W., Chemical Kinetic Data Base for Combustion Chemistry. Part 2. Methanol. Journal of Physical and Chemical Reference Data, 1987. 16(3): p. 471-508.14. Becke, A.D., Density‐functional thermochemistry. II. The effect of the Perdew–Wang generalized‐gradient correlation correction. The Journal of Chemical Physics, 1992. 97(12): p. 9173-9177.15. Becke, A.D., Density‐functional thermochemistry. I. The effect of the exchange‐only gradient correction. The Journal of Chemical Physics, 1992. 96(3): p. 2155-2160.16. Becke, A.D., Density‐functional thermochemistry. III. The role of exact exchange. The Journal of Chemical Physics, 1993. 98(7): p. 5648-5652.17. Yang, W., R.G. Parr, and C. Lee, Various functionals for the kinetic energy density of an atom or molecule. Physical Review A, 1986. 34(6): p. 4586-4590.18. Hehre W. , R.L., Schleyer P. V. R. , and Pople J. A. and 30, Ab Initio Molecular Orbital Theory. 1986, New York: Wiley.19. Andersson, M.P. and P. Uvdal, New Scale Factors for Harmonic Vibrational Frequencies Using the B3LYP Density Functional Method with the Triple-ζ Basis Set 6-311+G(d,p). The Journal of Physical Chemistry A, 2005. 109(12): p. 2937-2941.20. Raghavachari, K., et al., A fifth-order perturbation comparison of electron correlation theories. Chemical Physics Letters, 1989. 157(6): p. 479-483.21. M.J. Frisch, G.W.T., H.B. Schlegel, et al., GAUSSIAN 09, Revision C.01, Gaussian Inc., Wallingford CT, 2010.22. Robson Wright, M., Theories of Chemical Reactions, in An Introduction to Chemical Kinetics. 2005, John Wiley & Sons, Ltd. p. 99-164.23. Goos, E.B., A.; Ruscic, B., Extended Third Millennium Ideal Gas and Condensed Phase Thermochemical Database for Combustion with Updates from Active Thermochemical Tables. http://garfield.chem.elte.hu/Burcat/burcat.html, October, 2017.

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An Investigation of the Methanol Decomposition Behind Incident Shock Waves

Cited by 29 publications

References 18 publications

Methanol and Ethanol Decomposition in Supercritical Water

Methanol and Ethanol Decomposition in Supercritical Water

Absolute Reactive Cross Section for H Atom Formation in the Reaction of Translationally Energetic O(¹D) Atoms with Methane

Kinetics of the Reaction of Methyl Radical with Methanol

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An Investigation of the Methanol Decomposition Behind Incident Shock Waves

Cited by 29 publications

References 18 publications

Methanol and Ethanol Decomposition in Supercritical Water

Methanol and Ethanol Decomposition in Supercritical Water

Absolute Reactive Cross Section for H Atom Formation in the Reaction of Translationally Energetic O(1D) Atoms with Methane

Kinetics of the Reaction of Methyl Radical with Methanol

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Product

Resources

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Absolute Reactive Cross Section for H Atom Formation in the Reaction of Translationally Energetic O(¹D) Atoms with Methane