The Mechanism of Coke Formation on Catalysts

https://doi.org/10.1016/S0167-2991(08)65236-2Get rights and content

The formation and deposition of coke on the catalyst causes deactivation in the catalytic processing of heavy oils. Experimental data is presented on the processing of heavy oils to elucidate coke formation. Models are given of coke accumulation and transformation on catalyst surfaces. An analogy to mesophase formation in the coking of aromatic liquids is proposed as a mechanism related to the coking of catalysts.

References (8)

  • O. A. Larson, Proceedings of Oblad Conference, October, 1979, Snowbird, UT, to be...
  • T.F. Yen et al.

    Anal. Chem.

    (1961)
  • Shibata Kavru et al.

    Fuel

    (1978)
  • O.A. Larson et al.

    Ind. Eng. Chem. Process Design and Development

    (1962)
There are more references available in the full text version of this article.

Cited by (64)

  • Steam reforming of n-hexane and toluene: Understanding impacts of structural difference of aliphatic and aromatic hydrocarbons on their coking behaviours

    2021, Journal of Environmental Chemical Engineering
    Citation Excerpt :

    Both the amorphous carbon and filamentous carbon nanotubes were formed in the used catalysts in steam reforming of either n-hexane or toluene. The amorphous coke could cover the metallic sites, which could lead to the fast deactivation of the catalyst during the reforming reaction [48,55–61]. Although the amorphous coke could be identified in the used catalysts from steam reforming of n-hexane, the proportion should not be significant as the catalyst maintained the catalytic activity.

  • Cold model testing of in-situ catalyst activation by swirling self-rotation in ebullated bed reactor for biomass pyrolysis oils hydrogenation

    2021, Chemical Engineering Journal
    Citation Excerpt :

    It’s hoped that the long-term operation of the ebullated bed reactor can be realized by improving the activity and anti-carbon capacity of the catalyst, slowing down the deactivation rate of the catalyst and prolonging its service life [15]. Catalyst deactivation in the ebullated bed reactor is caused by coke, which covers the catalyst surface, blocks the pore canal, and obstructs the entry and exit of the reactants and the products [16–20]. Additionally, researches have been focused on slowing down the coking of the catalyst by inhibiting the polymerization reaction through the addition of appropriate solvents [21,22].

  • Modeling of hydrotreating catalyst deactivation for heavy oil hydrocarbons

    2018, Fuel
    Citation Excerpt :

    If there is not a proper ratio of asphaltenes, oil, and resins, the colloid stability of the feed cannot be maintained provoking asphaltene precipitation [23]. During hydroprocessing it is important to remove the resins at about the same rate as asphaltenes, otherwise, precipitation of asphaltenes from the feed can be a major cause of coke formation [24]. Hydrotreated asphaltenes become more aromatic than the original asphaltenes.

  • Effect of pore size distribution (PSD) of Ni-Mo/Al<inf>2</inf>O<inf>3</inf> catalysts on the Saudi Arabia vacuum residuum hydrodemetallization (HDM)

    2016, Catalysis Today
    Citation Excerpt :

    This indicates that coke deposition block the pore mouth to small pores [16,23]. Pore volume loss data in Table 3 indicate that the volume of pore in <10 nm size and pores in 10–20 nm size are easily affected while the macro pore volume changes little [37–39], resulting in a larger average pore diameter of spent catalysts compared to the fresh ones [23,40]. Isaza et al. reported that small pores were blocked and some of large pores were partially blocked under the reaction conditions [15].

View all citing articles on Scopus
View full text