Elsevier

Catalysis Today

Volume 4, Issues 3–4, February 1989, Pages 355-363
Catalysis Today

The homogeneous gas phase oxidation of methane and the retarding effect of basic/inert surfaces

https://doi.org/10.1016/0920-5861(89)85031-XGet rights and content

Abstract

The homogeneous gas phase O2-based oxidation of methane was studied in the temperature range, from 500°C to 750°C at methane partial pressures ranging from 3 bar to 40 bar. At the lower end of the temperature range methanol, formaldehyde, and CO represent the main products, while at temperatures exceeding 650° C/C-coupled products, C2H6, C2H4, C3H6 and C3H8 predominate. The change in selectivity as function of the temperature is well explained based on a free radical chain mechanism with degenerate branching, initiated by the gas phase reaction, CH4+O2→CH·3+HO·2. Bringing in basic catalysts known to catalyze the system at low methane partial pressures, in the reactor e.g. SrCO3, BaCO3, and 7% Li/MgO resulted in reduced rates of methane and oxygen conversions, and only minor changes in the selectivity to coupled products were observed.

References (11)

  • D.E. Hoare et al.

    The Fifth Symposium on Combustion, N.Y.

    (1955)
    D.E. Hoare et al.

    The Fifth Symposium on Combustion, N.Y.

    (1955)
  • S. Mahajan et al.

    Ind. Eng. Chem.

    (1977)
  • N.N. Semenov
  • W.A. Bone et al.

    Proc. Roy. Soc., A

    (1936)
  • G. Rotzoll

    Combustion Science and Technology

    (1986)
There are more references available in the full text version of this article.

Cited by (52)

  • Comparison of mechanisms for the direct, gas phase, partial oxidation of methane to methanol

    2021, Chemical Engineering Science
    Citation Excerpt :

    From this appendix over 100 data points were randomly selected, and the simulations were run to compare the conversion of methane and methanol selectivity predicted to these experimental points. The data used are from the following authors: NNewitt and Haffnerewitt and Haffner (1932); NNewitt and Schmidtewitt and Schmidt (1937); Boomer and Thomas (1937); Furman and Shestakova (1956); Oberdorfer and Winch (1961); Lott and Sliepcevich (1967); Tripathy (1975); LLuckett and Mileuckett and Mile (1976); BBrockhaus and Frankerockhaus and Franke (1981); Gesser et al. (1985); Burch et al. (1989); Onsager et al. (1989); Hunter et al. (1990); Rytz and Baiker (1991); Walsh et al. (1992); Yarlagadda et al. (1988). A separate selection of data (over 100 data points) was compiled from literature using only results from quartz reactors.

  • The interplay of catalytic and gas-phase stages at oxidative conversion of methane: A review

    2017, Journal of Molecular Catalysis A: Chemical
    Citation Excerpt :

    As ethylene accumulates, the reaction transforms into the gas-phase process of oxidation of methane and ethylene to CO and CH3OH. The influence of a number of heterogeneous catalysts (SrCO3, BaCO3, and 7% Li/MgO), active in the oxidative condensation of methane at low pressures, on the process at 500–750 °C was studied in [49]. However, at pressures above 3 atm, no contribution from heterogeneous activation was detected, in agreement with the estimates of the pressure range of transition to chain-branched oxidation obtained in [50].

  • An EPR and NMR study on Mo/HZSM-5 catalysts for the aromatization of methane: Investigation of the location of the pentavalent molybdenum

    2013, Journal of Molecular Catalysis A: Chemical
    Citation Excerpt :

    Several routes have been explored over the previous two decades. In addition to methane conversion into syn gas which is of real industrial significance, more ambitious routes such as direct conversion into oxygenates [1–4], methanation of olefins, although this is a barely effective route to methane insertion in view of the unfavorable thermodynamics at the temperatures needed to activate methane and to reach measurable reaction rates [5], oxidative coupling of methane [6–9] and conversion of methane into benzene and hydrogen [10–29] were explored. The latest developments were concerned with the latter reaction carried out in the presence of various transition metal oxide-loaded inorganic carriers.

View all citing articles on Scopus
View full text