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Selective and complete catalytic oxidation of natural gas in Turbulent Fluidized Beds

  • Jamal Chaouki
  • Danilo Klvana
  • Christophe Guy
Article

Abstract

Turbulent Fluidized Bed (TFB) reactors appears to be ideal for exothermic and fast reactions such as catalytic oxidation of methane. In this paper, a use of TFB reactor for two catalytic oxidation of methane: catalytic combustion of methane and catalytic selective oxidation of methane for the ethylene synthesis is described. Catalytic fluidized bed combustion of methane is shown to be an emerging technology capable of meeting all environmental constraints as far as nitrogen oxides and carbon monoxide are concerned. This reaction carried out in both the bubbling and the turbulent regimes at 450-500 ‡C shows that the turbulent regime is more favourable. A self-sustained combustion with complete conversion and a zero emission of NOx and CO was achieved with a mixture of 4% methane in air at 500 ‡C. The two-phase model of Werther [1990], which phenomenologically introduces the enhancement factor due to chemical reaction, predicts quite well the combustor performance. The same model but without enhancement factor (slower reactions) predicts satisfactorily the experimental data for the oxidative coupling of methane and can be used to quantify the influence of homogeneous and catalytic reactions.

Key words

Turbulent Fluidized Bed Modelling Catalytic Selective Oxidation Combustion Natural Gas 

References

  1. Abed, R., “Fluidization,” Kunii, D., et Toei, R. eds., Engineering Foundation,137, 7 (1994).Google Scholar
  2. Al-Zahrani, S., Song, Q. and Lobban, L., “Effects of CO2 during Oxidative Coupling of Methane over Li/MgO: Mechanisms and Models,”Ind. Eng. Chem. Res.,33, 251 (1994).CrossRefGoogle Scholar
  3. Avidan, A., “Turbulent Fluid Bed Reactors using Fine Powder Catalysts,” AIChE-CIESCMtg Beijing, 411 (1982).Google Scholar
  4. Berruti F., Chaouki, J., Godfrey, L., Pugsley, T. S. and Patience, G. S., “Hydrodynamics of Circulating Fluidized Bed Risers: a Review,”Can. J. Chem.,73, 579 (1995).Google Scholar
  5. Bi, H. T. and Grace, J. R., “Effect of Measurement Method on the Velocities Used to Demarcate the Onset of Turbulent Fluidization,”Chem. Eng. J.,57, 261 (1995).Google Scholar
  6. Cai, P., Jin, Y., Yu, Z. Q. and Wang, Z. W., “Mechanism of Flow Regime Transition from Bubbling to Turbulent Fluidization,”AIChE J.,36,955(1990).CrossRefGoogle Scholar
  7. Chaouki, J., Guy, C., Sapunzhiev, C. and Klvana, D., “Combustion of Methane in a Cyclic Catalytic Reactor,”Ind. Eng. Chem. Res.,33, 2957 (1994).CrossRefGoogle Scholar
  8. Chaouki, J., Gonzalez, A., Guy, C. and Klvana D., “Two-Phase Model for a Catalytic Turbulent Fluidized Bed Reactor : Application to Ethylene Synthesis,”Chem. Eng. Sci., accepted (1999).Google Scholar
  9. Chehbouni, A., Chaouki, J., Guy, C. and Klvana, D., “Characterization of the Flow Transition between Bubbling and Turbulent Fluidization,”Ind. Eng. Chem. Res.,3, 324 (1994).Google Scholar
  10. Chehbouni, A., Chaouki, J., Guy, C. and Klvana, D., “Effets de différents paramètres sur la vitesse de transition de la fluidisation en régime turbulent,”Can. J. Chem. Eng.,4, 134 (1993).Google Scholar
  11. Davidson, J. F. and Harrison, D., “Fluidization,” Cambridge University Press, New York (1963).Google Scholar
  12. Foka, M., Chaouki, J., Guy, C. and Klvana, D., “Gas Phase Hydrodynamics of a Gas-Solid Fluidized Bed,”Chem. Eng. Sci.,51(5), 713 (1996).CrossRefGoogle Scholar
  13. Foka, M., Chaouki, J., Guy, C. and Klvana, D., “Natural Gas Combustion in a Catalytic Turbulent Fluidized Bed,”Chem. Eng Sci.,49(24), 4269 (1994).CrossRefGoogle Scholar
  14. Grace, J. R. and Sun, G., “Influence of Particle Size Distribution on the Performance of Fluidized Bed Reactors,”Can. J. Chem. Eng.,69, 1126(1991).Google Scholar
  15. Grace, J. R., “High Velocity Fluidized Beds Reactors,”Chem. Eng Sci.,45(8), 1953 (1990).CrossRefGoogle Scholar
  16. Horio, M., “Hydrodynamics,” in Circulating Fluidized Beds, ed. Grace, J. R., Avidan, A. A. and Rnowlton, T. M., Blackie Academic & Professional, London 1-21-85 (1997).Google Scholar
  17. Horio, M., “The Onset of Turbulent Fluidized Beds,”J. Soc. Powder Tech. Japan,23, 20 (1986).Google Scholar
  18. Kehoe, P. W. K. and Davidson, J. F., “Continuously Slugging Fluidized Beds,”Instn. Chem. Engrs. Sym. Sen,33, 97 (1971).Google Scholar
  19. Lanneau, K. P., “Gas-solids Contacting in Fluidized Bed,”Trans IChemE,38, 125 (1960).Google Scholar
  20. Lee, G. S. and Kim, S. D., “Gas Mixing in Slugging and Turbulent Fluidized Beds,”Chem. Eng. Comm.,86, 91 (1989).CrossRefGoogle Scholar
  21. Massimilla, L., “Behavior of Catalytic Beds of Fine Particles at High Gas Velocities,”AIChE Symp Ser,69, 11 (1973).Google Scholar
  22. Massimilla, L., “In Fluidization,” 2nd edition Academic Press, New York (1985)Google Scholar
  23. May, W. G., “Fluidized Bed Reactor Studies,”Chem. Eng. Progr.,55, 49 (1959).Google Scholar
  24. Miwa, K., Mori, S., Kato, T. and Muchi, I., “Mixing and Contacting in Gas-Solid Fluidized Beds,”Chem. Eng.,12, 187 (1972).Google Scholar
  25. Mleczko, L., Andorf, R. and Baerns, M., “Prediction of the Performance of a Fluidized Bed Reactor for the Catalytic Oxidative Methane Coupling to C2 Hydrocarbons,” AICHE Annual Meeting, Nov. 11–16, Chicago (1990).Google Scholar
  26. Mori, S. and Wen, C. Y., “Estimation of Bubble Diameter in Gaseous Fluidized Beds,”AIChE J.,20, 109 (1975).CrossRefGoogle Scholar
  27. Rowe, P. N. and MacGillivray, H. J., In “Fluidization,” Edited by Grace, J. R. and Matsen J. M., New York, 545 (1980).Google Scholar
  28. Van Deemter, J. J., “Mixing Patterns in Large-scale Fluidized Beds,”Chem. Eng Sci.,13, 143 (1961).CrossRefGoogle Scholar
  29. Van Swaij, V P. M. and Zuiderweg, F. J., Proc. Inter. Symp. on Fluidization and Its Applications. Edited by Cepadues, Toulouse, France, 454 (1973).Google Scholar
  30. Van Swaij, V. P. M., “The Design of Gas-solids Fluid Bed and Related Reactor,”ACS Symp Sen,72, 193 (1978).CrossRefGoogle Scholar
  31. Wen, C. Y., “Chemical Reaction in Fluidized Beds,” In Recent Advances in the Engineering Analysis of Chemically Reacting Systems,” Edited by Doraisamy, L. K., Wiler Eastern, New Delhi, 256 (1984).Google Scholar
  32. Werther, J., “Mathematical Modeling of Fluidized Bed Reactors,”Intern. Chem. Eng.,20(4), 529 (1980).Google Scholar
  33. Zenz, F. A., “Two Phase Fluid-Solid Flow,”Ind. Eng. Chem.,41, 2801 (1949).CrossRefGoogle Scholar
  34. Zhang, W, Tung, Y. and Johnson, F., “Radial Voidage Profiles in Fast Fluidized Beds of Differents Diameters,”Chem. Eng. Sci.,46,3045(1991).CrossRefGoogle Scholar

Copyright information

© Korean Institute of Chemical Engineering 1999

Authors and Affiliations

  1. 1.Chemical Engineering DeptEcole PolytechniqueMontreal, QuebecCanada

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