Advertisement

Heterogeneous Reactions of Char and Carbon

  • F. Douglas Skinner
  • L. Douglas Smoot

Abstract

The combustion or gasification of coal may be thought of as occurring in several steps. First, the coal is heated at high rates, and rapid devolatilization occurs. The volatiles then react in the gas phase. (These processes are discussed in detail in Chapters 8 and 10.) The char remaining after devolatilization consists primarily of carbon, together with the major part of the ash components and some volatile matter. The heterogeneous reactions of the char with oxidizing gases (oxygen, steam, carbon dioxide, etc.) account for the majority of time required for particle burnout. In addition, in the case of gasification, the reaction of char with hydrogen may also become important, especially for high hydrogen partial pressures.

Keywords

Reaction Order Heterogeneous Reaction Bituminous Coal Petroleum Coke Pore Diffusion 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    D. Anson, F. D. Moles, and P. J. Street, Structure and surface area of pulverized coal during combustion, Combust. Flame 16, 265–274 (1971).CrossRefGoogle Scholar
  2. 2.
    L. D. Smoot, M. D. Horton, and G. Williams, Propagation of laminar pulverized coal-air flames, in Sixteenth Symposium (International) on Combustion, The Combustion Institute, Pittsburgh, Pa., pp. 375–387 (1977).Google Scholar
  3. 3.
    M. A. Field, Predicting the burning time of the coke residue of pulverized fuel, Brit. Coal Utiliz. Res. Assoc. Mon. Bull. 28 (2), 61–75 (1964).Google Scholar
  4. 4.
    P. L. Walker, Jr., F. Rusinko, Jr., and L. G. Austin, Gas reactions of carbon, Advan. Catal. 11, 135–221 (1959).Google Scholar
  5. 5.
    D. Gray, J. G. Cogoli, and R. H. Essenhigh, Problems in pulverized coal and char combustion, Advan. Chem. Ser. 131, 72–91 (1974).CrossRefGoogle Scholar
  6. 6.
    M. A. Field. D. W. Gill, B. B. Morgan, and P. G. W. Hawksley, Combustion of pulverized fuel. Part 6. Reaction rate of carbon particles, Brit. Coal Utiliz. Res. Assoc. Mon. Bull. 31 (6), 285–345 (1967).Google Scholar
  7. 7.
    H. W. Batchelder, R. M. Busche, and W. P. Armstrong, Kinetics of coal gasification, Ind. Eng. Chem. 45 (9), 1856–1878 (1953).CrossRefGoogle Scholar
  8. 8.
    C. G. von Fredersdorff and M. A. Elliot, in Chemistry of Coal Utilization, Supplementary Volume ( H. H. Lowry, ed.) pp. 892–1022, John Wiley and Sons, New York (1963).Google Scholar
  9. 9.
    D. B. Anthony and J. B. Howard, Coal devolatilization and hydrogasification, AIChE J. 22, 625–656 (1976).CrossRefGoogle Scholar
  10. 10.
    P. L. Walker, Jr., R. J. Foresti, Jr., and C. C. Wright, Surface area studies of carbon-carbon dioxide reaction, Incl. Eng. Chem. 45 (8), 1703–1710 (1953).CrossRefGoogle Scholar
  11. 11.
    W. J. Thomas, Effect of oxidation on the pore structure of some graphitized carbon blacks, Carbon 3, 435–443 (1977).CrossRefGoogle Scholar
  12. 12.
    C. Y. Wen, Optimization of Coal Gasification Processes, R & D Report No. 66, Interim Report No. 1, Office of Coal Research Contract No. 14–01–0001–497 (1972).Google Scholar
  13. 13.
    A. Tornita, O. P. Mahajan, and P. L. Walker, Jr., Catalysis of char gasification by minerals. ACS Div. Fuel Chem. Preprints 22 (1), 4–6 (1977).Google Scholar
  14. 14.
    G. D. Sergeant and I. W. Smith. Combustion rates of bituminous coal char in the temperature range 800 to 1700 K, Fuel 52, 52–57 (1973).CrossRefGoogle Scholar
  15. 15.
    R. J. Hamor, I. W. Smith, and R. J. Tyler, Kinetics of combustion of a pulverized brown coal char between 630 and 2200 K, Combust. Flame 21, 153 162 (1973).Google Scholar
  16. 16.
    M. A. Field, Rate of combustion of size-graded fractions of char from a low-rank coal between 1200 K and 2000 K, Combust. Flame 13, 237–252 (1969).CrossRefGoogle Scholar
  17. 17.
    M. F. R. Mulcahy and I. W. Smith, Kinetics of combustion of pulverized fuel: A review of theory and experiment, Rev. Pure and Appl. Chem. 19, 81–108 (1969).Google Scholar
  18. 18.
    J. A. Arthur, Reactions between carbon and oxygen, Trans. Faraday Soc. 47, 164–178 (1951).CrossRefGoogle Scholar
  19. 19.
    M. Rossberg, Experimental results concerning the primary reactions in the combustion of carbon, Z. Elecktrochem. 60, 952–956 (1956).Google Scholar
  20. 20.
    R. J. Day, Kinetics of the Carbon-Oxygen Reaction at High Temperatures, Ph.D. Thesis, The Pennsylvania State University, University Park, Pa. (1949).Google Scholar
  21. 21.
    I. W. Smith and R. J. Tyler, The reactivity of a porous brown coal char to oxygen between 630 and 1812 K. Combust. Sci. Technol. 9, 87–94 (1974).CrossRefGoogle Scholar
  22. 22.
    R. H. Essenhigh, R. Froberg, and J. B. Howard, Predicted burning rates of single carbon particles, Ind. Eng. Chem. 57 (9), 33–43 (1965).CrossRefGoogle Scholar
  23. 23.
    J. B. Howard and R. H. Essenhigh, Mechanism of solid particle combustion with simultaneous gas-phase volatiles combustion, in Eleventh Symposium (International) on Combustion, pp. 399–408, The Combustion Institute, Pittsburgh, Pa. (1967).Google Scholar
  24. 24.
    M. A. Nettleton, Burning rates of devolatilized coal particles, Ind. Eng. Chem. Fundam. 6 (1). 20–25 (1967).CrossRefGoogle Scholar
  25. 25.
    I. W. Smith, Kinetics of combustion of pulverized semi-anthracite in the temperature range 1400–2200 K, Combust. Flame 17, 421–428 (1971).CrossRefGoogle Scholar
  26. 26.
    I. W. Smith and R. J. Tyler, Internal burning of pulverized semi-anthracite: The relation between particle structure and reactivity, Fuel 51, 312–321 (1972).CrossRefGoogle Scholar
  27. 27.
    R. J. Tyler, H. J. Wouterhood, and M. F. R. Mulchahy, Kinetics of the graphite-oxygen reaction near 1000 K, Carbon 14, 271–278 (1976).CrossRefGoogle Scholar
  28. 28.
    N. M. Laurendeau, Heterogeneous kinetics of coal char gasification and combustion. in Progress in Energy and Combustion Science, Pergamon Press, London, England (1978), in press.Google Scholar
  29. 29.
    S. Ergun and M. Mentser, in The Chemistry and Physics of Carbon (P. L. Walker, ed.), Vol. 1, pp. 203–263, Marcel Dekker, Inc., New York (1965).Google Scholar
  30. 30.
    W. K. Lewis, E. R. Gilliland, and G. T. McBride, Jr., Gasification of carbon by carbon dioxide in fluidized powder bed, Ind. Eng. Chem. 41 (6), 1213–1226 (1949).CrossRefGoogle Scholar
  31. 31.
    J. P. Blakely and L. G. Overholser, Oxidation of ARJ graphite by low concentrations of water vapor and carbon dioxide in helium, Carbon 3, 269–275 (1965).CrossRefGoogle Scholar
  32. 32.
    E. T. Turkdogan and J. V. Vinters, Effect of carbon monoxide on the rate of oxidation of charcoal, graphite and coke in carbon dioxide, Carbon 8, 39–53 (1970).CrossRefGoogle Scholar
  33. 33.
    A. E. Reif, The Mechanism of the carbon dioxide-carbon reaction, J. Phys. Chem. 56, 785–788 (1952).CrossRefGoogle Scholar
  34. 34.
    H. J. Grabke, Oxygen transfer and carbon gasification in the reaction of different carbons with CO2, Carbon 10, 587–599 (1972).CrossRefGoogle Scholar
  35. 35.
    R. T. Yang and M. Steinberg, The reactivity of coal chars with CO2 at 1100–1600°C, ACS Div. Fuel Chem. Preprints 22 (1), 12–16 (1977).Google Scholar
  36. 36.
    A. M. Mayers, The rate of reduction of carbon dioxide by graphite, J. Am. Chem. Soc. 56, 70–76 (1934).CrossRefGoogle Scholar
  37. 37.
    S. A. Pursley, R. A. Matula, and O. W. Witzell, The kinetics of carbon dioxide and carbon formation from carbon monoxide, J. Phys. Chem. 70, 3768–3770 (1966).CrossRefGoogle Scholar
  38. 38.
    C. Y. Chen, Mechanism of the Steam-Carbon Reaction in a Flow System, Ph.D. Dissertation, University of Illinois, Urbana, Illinois (1951).Google Scholar
  39. 39.
    E. S. Golovina and G. P. Khaustovich, Interaction of carbon with carbon dioxide at high temperatures, Teplofiz. Vys. Temp. 2, 267–273 (1974).Google Scholar
  40. 40.
    A. K. Mehta, Mathematical Modeling of Chemical Processes for Low Btu Gasification of Coal for Electric Power Generation, ERDA Report No. FE-1545–26 (August 1976).Google Scholar
  41. 41.
    R. W. Taylor and D. W. Bowman, Rate of Reaction of Steam and Carbon Dioxide with Chars Produced from Subbituminous Coals, Lawrence Livermore Laboratory, Report No. UCRL52002 (1976).Google Scholar
  42. 42.
    R. L. Coates, Kinetic data from a high temperature entrained flow gasifier, ACS Div. Fuel Chem. Preprints 22 (1), 84–92 (1977).Google Scholar
  43. 43.
    T. H. Blakeley, Gasification of carbon in carbon dioxide and other gases at temperatures above 900 K, in Proceedings of the 4th Conference on Carbon, Buf alo, New York, 1959, 95–105 (1960).Google Scholar
  44. 44.
    E. A. Gulbransen, K. F. Andrew, and F. A. Brassart, Reaction of graphite with carbon dioxide at 1000–1600-C under flow conditions, Carbon 2, 421–429 (1965).CrossRefGoogle Scholar
  45. 45.
    E. E. Peterson and C. C. Wright, Reaction of artificial graphite with carbon dioxide, Ind. Eng. Chem. 47 (8), 1624–1634 (1955).CrossRefGoogle Scholar
  46. 46.
    J. Gadsby, C. N. Hinshelwood, and K. W. Sykes, The kinetics of the reactions of the steam-carbon system, Roy. Soc. London Proc. 187A, 129–151 (1946).CrossRefGoogle Scholar
  47. 47.
    A. Linares, O. P. Mahajan, and P. L. Walker, Jr., Reactivities of heat-treated coals in steam, ACS Div. Fuel Chem. Preprints 22 (1), 1–3 (1977).Google Scholar
  48. 48.
    A. M. Mayers, The rate of oxidation of graphite by steam, J. Am. Chem. Soc. 56, 1879–1881 (1934).CrossRefGoogle Scholar
  49. 49.
    H. E. Klei, J. Sahagian, and D. W. Sundstrom, Kinetics of the activated carbon-steam reaction, Ind. Eng. Chem. Process Des. Dev. 14, 470–473 (1975).CrossRefGoogle Scholar
  50. 50.
    B. E. Reide and D. Hanesian, Kinetic study of carbon-steam reaction, Ind. Eng. Chem. Process Des. Dev. 14, 70–74 (1975).CrossRefGoogle Scholar
  51. 51.
    J. A. Dotson, W. A. Koehler, and J. H. Holden, Rate of the steam-carbon reaction by a falling-particle method, Ind. Eng. Chem. 49 (1), 148–154 (1957).CrossRefGoogle Scholar
  52. 52.
    H. L. Feldkirchner and J. Huebner, Reaction of coal with steam-hydrogen mixtures at high temperatures and pressures, Ind. Eng. Chem. Process Des. Der. 4, 134–142 (1965).CrossRefGoogle Scholar
  53. 53.
    R. Piccirelli, Survey of Surface Rates of Carbon-Gas Reactions and Carbon Vaporization: A Final Report, submitted to KMS Industries, Contract No. F12593, Feb. 28, 1975.Google Scholar
  54. 54.
    P. P. Feistel, K. H. von Heek, H. Juntgen, and A. H. Pulsifer, Gasification of a German bituminous coal with H2O, H2, and H2O-H2 mixtures, ACS Div. Fuel Chem. Preprints 22 (1), 53–76 (1977).Google Scholar
  55. 55.
    C. W. Zielke and E. Gorin, Kinetics of carbon gasification, Ind. Eng. Chem. 47, 820–825 (1955).CrossRefGoogle Scholar
  56. 56.
    J. D. Blackwood and F. McGrory, The carbon-steam reaction at high pressure, Austral. J. Chem. 11, 16–33 (1957).CrossRefGoogle Scholar
  57. 57.
    J. L. Johnson, Kinetics of initial coal hydrogasification stages, ACS Div. Fuel Chem. Preprints 22 (1), 17–37 (1977).Google Scholar

Copyright information

© Springer Science+Business Media New York 1979

Authors and Affiliations

  • F. Douglas Skinner
    • 1
  • L. Douglas Smoot
    • 2
  1. 1.Chemical EngineeringBrigham Young UniversityProvoUSA
  2. 2.Brigham Young UniversityProvoUSA

Personalised recommendations