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Abstract

Kinetics of hydrodesulfurization of dibenzothiophene (DBT) has been studied on a commercial CoMo/γ-Al2O3 catalyst at 633 - 683 K and 10 atm. A low DBT concentration typically obtained in hydrodesulfurization operations was used. Pseudo-first-order model was found to fit the experimental data for the consumption of DBT. The activation energy for the conversion of DBT was found to be 51.7 kcal/mol. Biphenyl (BP) and cyclohexylbenzene (CHB) were obtained as dominant products. For the reaction network, both parallel and parallel-sequential routes were explored. The latter was found to give a better description of the BP and CHB distributions. The ratio of BP to CHB depended on the reaction temperature. The values of activation energies of DBT hydrogenolysis to BP (EBP), DBT hydrogenation to CHB (ECHB1) and hydrogenation of BP to CHB (ECHB2) were found to be in a decreasing order of ECHB2 > EBP > ECHB1. The result suggests the presence of different catalytic sites leading to the two products on the catalysts.

 

Keywords

Hydrodesulfurization Dibenzothiophene CoMo/Al2O3 Biphenyl Cyclohexylbenzene Kinetics

Article Details

How to Cite
Al-Zeghayer, Y., & Jibril, B. (2006). Kinetics of Hydrodesulfurization of Dibenzothiophene on Sulfided Commercial Co-Mo/γ-Al2O3 Catalyst. The Journal of Engineering Research [TJER], 3(1), 38–42. https://doi.org/10.24200/tjer.vol3iss1pp38-42

References

  1. Al-Zeghayer, Y.S., Sunderland, Y.S., Al-Masry, Y.W., Al- Mubaddel, F., Ibrahim, A.A., Bhartiya, B.K. and Jibril, B.Y., 2005, “Activity of CoMo/γ -Al2 O3 as a Catalyst in Hydro-desulfurization: Effects of Co/Mo Ratio and Drying Condition," Appl. Catal. A , Vol. 282, pp. 1-10.
  2. Bartsh, R. and Tanielian, C., 1974, "Hydrodesulfurization: I. Hydrogenolysis of Benzothiophene and Dibenzothiophene over CoO-MoO3 -Al2 O3 Catalyst," J. Catal , Vol. 35, p. 353.
  3. Broderick, D.H., 1980, Ph.D Dissertation, University of Delaware, Newark, Delaware.
  4. Broderick, D.H. and Gates, B.C., 1981, "Hydro-desulfurization and Hydrogenation of Dibenzothiophene Catalyzed by Sulfided Co-Mo/γ -Al2 O3 : The Reaction Kinetics," AIChEJ , Vol. 27, p. 663.
  5. Da Costa, P., Potvin, C., Manoli, J.M., Lemberton, J.L., Perot, G. and Djega-Mariadassou, G., 2002, "New
  6. Catalysts for Deep Hydrotretment of Diesel Fuel: Kinetics of 4,6-Dimethyldibenzothiophene Hydrodesulfurization Over Alumina-Supported Molybdenum Carbide," J. Mol. Catal . A , Vol. 184 p. 323.
  7. Damyanova, S., Petrov, L. and Grange, P., 2003, "XPS Characterization of Zirconium-promoted CoMo Hydrodesulfurization Catalysts," Appl. Catal. A , Vol. 239, p. 241.
  8. Farag, H., Sakanishi, K., Mochida, I. and Whitehurst, D.D., 1999, "Kinetic Analyses and Inhibition by Naphthalene and H2S in Hydrodesulfurization of 4,6- dimethyldibenzothiophene (4,6-DMDBT) Over CoMo-based Carbon Catalyst," Energy and Fuel , Vol. 13, p. 449.
  9. Farag, H., Whitehurst, D.D., Sakanishi, K. and Mochida, I., 1997, "Catalysis in Fuel Processing and Environmental Protection," Proc. 214th National Meeting of ACS Sep 7-11, Las Vegas, USA, Am.
  10. Chem. Soc , Vol. 42 p. 569.
  11. Federal Register 65 (2000) 35430.
  12. Girgis, M.J. and Gates, B.C., 1991, "Reactivities, Reaction Networks, and Kinetics in High-Pressure Catalytic Hydroprocessing," Ind. Eng. Chem . Res , Vol. 30, p. 2021.
  13. Levenspiel, O., 1972, Chemical Reaction Engineering , 2nd edn, John Wiley & Sons, New York.
  14. Papadopoulou, C., Vakros, J., Matralis, H.K., Kordulis, C. and Lycourghiotis, A., 2003, “On the Relationship between the Preparation Method and the Physicochemical and Catalytic Properties of the CoMo/γ -Al2 O3 Hydrodesulfurization Catalysts," J. Coll. Interf. Sci , Vol. 261, pp. 146.
  15. Pille, R.C., Yu, C. and Froment, G.F., 1994, "Kinetic Study of the Hydrogen Sulfide Effect in the Conversion of Thiophene on Supported Co-Mo Catalysts," J. Mol. Catal , Vol. 94, p. 369.
  16. Prins, R., de Beer, V.H.J. and Somorjai, G.A., 1989, "Structure and Function of the Catalyst and the Promoter in Co-Mo Hydrodesulfurization Catalysts," Catal. Rev. Sci. Eng , Vol. 31 p. 1.
  17. Rollmann, L.D., 1977, "Catalytic Hydrogenation of Model Nitrogen, Sulfur, and Oxygen Compounds," J. Catal , Vol. 46, p. 243.
  18. Sapre, A.V. and Gates, B.C., 1980, "Prepr., Div. Fuel Chem., Hydrogenation of Aromatic Hydrocarbons Catalyzed by Sulfided CoO-Mo/γ -Al2 O3 : Reactivity, Reaction Network, and Kinetics," Am. Chem. Soc , Vol. 21, p. 66.
  19. Singhal, G.H., Espino, R.L., Sobel, J.E. and Huff, G.A., 1981, Hydrodesulfurization of Sulfur Heterocyclic Compounds: Kinetics of Dibenzothiophene," J. Catal , Vol. 67, p. 457.
  20. Steiner, P. and Blekkan, E.A., 2002, “Catalytic Hydrodesulfurization of a Light Oil Over a NiMo Catalyst: Kinetics of Selected Sulfur Components,” Fuel Process. Tech , Vol. 79 p. 1.
  21. Topsoe, H. and Clausen, B.S., 1984, "Importance of Co- Mo-S Type Structures in Hydrodesulfurization," Catal. Rev. Sci. Eng , Vol. 26, p. 395.
  22. Venezia, A.M., La Parola, V., Deganello, G., Cauzzi, D., Leonardi, G. and Predieri, G., 2002, "Influence of the Preparation Method on the Thiophene HDS Activity of Silica Supported CoMo Catalysts,” Appl. Catal. A , Vol. 229, p. 261.
  23. Wang, Y., Sun, Z., Wang, A., Ruan, A.L., Lifeng, L., Ren, J., Li, X., Li, C., Hu, Y. and Yao, P., 2004, "Kinetics of Hydrodesulfurization of Dibenzothiophene Catalyzed by Sulfided Co-Mo/MCM-41," Ind. Eng.
  24. Chem . Res , Vol. 43, p. 2324.
  25. Yang, P., Yan, F. and Liao, K., 2002, "A Study on the Effect of Preparation Parameters on the Catalytic Performance and Active Components of a new type Hydrodesulfurization Catalyst," Petr. Sci. Tech , Vol. 20, p. 763.