Cristin-resultat-ID: 980268
Sist endret: 2. februar 2013, 14:57
NVI-rapporteringsår: 2012
Resultat
Vitenskapelig artikkel
2012

Methane aromatisation based upon elementary steps: Kinetic and catalyst descriptors

Bidragsytere:
  • Kae S. Wong
  • Joris W. Thybaut
  • Elisabeth Tangstad
  • Michael Wilhelm Stöcker og
  • Guy B. Marin

Tidsskrift

Microporous and Mesoporous Materials
ISSN 1387-1811
e-ISSN 1873-3093
NVI-nivå 2

Om resultatet

Vitenskapelig artikkel
Publiseringsår: 2012
Publisert online: 2012
Trykket: 2012
Volum: 164
Sider: 302 - 312

Importkilder

Scopus-ID: 2-s2.0-84867396513
Isi-ID: 000310770100040

Beskrivelse Beskrivelse

Tittel

Methane aromatisation based upon elementary steps: Kinetic and catalyst descriptors

Sammendrag

An elementary steps-based kinetic model was developed for the ‘steady-state’ reaction kinetics of methane aromatisation over HMCM-22 and HZSM-5 supported Mo. The model adequately describes the experimentally observed trends over a wide range of operating conditions, i.e., temperatures from 873 to 973 K, space times between 32 and 161 kgcat s mol−1 and methane inlet molar fractions from 0.2 to 0.98 at atmospheric pressure. A benzene selectivity of 80 mol% can be achieved at 6% of methane conversion over Mo/HMCM-22 at 973 K. The reaction proceeds via similar pathways over Mo/HMCM-22 and Mo/HZSM-5: methane is first dimerised into ethene on Mo sites followed by ethene oligomerisation and cyclisation into benzene on the acid sites. Confinement effects induced by the larger pore mouth and near circular channel structure of ZSM-5 enhance the Mo dispersion, leading to a higher methane dimerisation rate coefficient over Mo/HZSM-5. Similar protonation enthalpies on MCM-22 and ZSM-5, i.e., -56 kJ mol−1 for hexene, indicate that both zeolites have acid sites with a comparable strength. Nevertheless, confinement effects result in a more pronounced reactant stabilisation by chemisorption on Mo/HZSM-5 compared to Mo/HMCM-22.

Bidragsytere

Kae S. Wong

  • Tilknyttet:
    Forfatter
    ved Universiteit Gent

Joris W. Thybaut

  • Tilknyttet:
    Forfatter
    ved Universiteit Gent

Elisabeth Tangstad

  • Tilknyttet:
    Forfatter
    ved Prosessteknologi ved SINTEF AS

Michael Wilhelm Stöcker

  • Tilknyttet:
    Forfatter
    ved Prosessteknologi ved SINTEF AS

Guy B. Marin

  • Tilknyttet:
    Forfatter
    ved Universiteit Gent
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