DOI QR코드

DOI QR Code

Kinetic study on Low-rank Coal Including K2CO3, Na2CO3, CaCO3 and Dolomite Gasification under CO2 Atmosphere

이산화탄소 분위기에서 K2CO3, Na2CO3, CaCO3 및 Dolomite가 첨가된 저급탄의 가스화에 대한 반응특성연구

  • Received : 2013.11.11
  • Accepted : 2014.01.10
  • Published : 2014.03.31

Abstract

We have investigated the effects of various additives on Eco coal gasification under $CO_2$ atmosphere. The temperature ranges from $750{\sim}900^{\circ}C$ and the gasification experimental was carried out with Eco coal adding 7 wt% $K_2CO_3$, $Na_2CO_3$, $CaCO_3$, Dolomite, and non-additive under $N_2$ and $CO_2$ gas mixture. At $850^{\circ}C$, we observed that the reaction rate increased when the concentration of $CO_2$ increased. However, we also observed that the increment of reaction rate was small at more than 70% of the concentration of $CO_2$. The additives activity was ranked as 7 wt% $Na_2CO_3$ > 7 wt% $K_2CO_3$ > non-additive > 7 wt% Dolomite > 7 wt% $CaCO_3$ at $850^{\circ}C$. At the temperatures of $750^{\circ}C$, $800^{\circ}C$, $850^{\circ}C$, and $900^{\circ}C$, when the temperature increased, the gasification rate increased. The gasification was suitably described by the volumetric reaction model. Using volumetric reaction model, the activation energy of Eco coal including 7 wt% $Na_2CO_3$ gasification was 83 kJ/mol, which was the lowest value among all the alkaline additives.

Keywords

Low-rank coal;Coal gasification;Additives;$CO_2$

References

  1. Ye, D., Agnew, J. B., and Zhang, D., "Gasification of a South Australian Low-rank Coal with Carbon Dioxide and Steam: Kinetics and Reactivity Studies," Fuel, 77(11), 1209-1219 (1998). https://doi.org/10.1016/S0016-2361(98)00014-3
  2. Ochoa, J., Cassanello, M., Bonelli, P., and Cukierman, A., "$CO_2$ Gasification of Argentinean Coal Chars: a Kinetic Characterization," Fuel Process Technol., 74(3), 161-176 (2001). https://doi.org/10.1016/S0378-3820(01)00235-1
  3. Sun, Z. Q., Wu, J. H., and Zhang, D., "$CO_2$ and $H_2O$ Gasification Kinetics of a Coal Char in the Presence of Methane," Energ. Fuel, 22(4), 2160-2165 (2008). https://doi.org/10.1021/ef8000949
  4. Trommer, D., and Steinfeld, A., "Kinetic Modeling for the Combined Pyrolysis and Steam Gasification of Petroleum Coke and Experimental Determination of the Rate Constants by Dynamic Thermogravimetry in the 500-1520 K Range," Energy Fuel, 20(3), 1250-1258 (2006). https://doi.org/10.1021/ef050290a
  5. Guzman, G. L., and Wolf, E. E., "Kinetics of the Potassium Carbonate-catalyzed Steam Gasification of Carbon and Coal," Ind. Eng. Chem. Process Des. Dev., 21(1), 25-29 (1982). https://doi.org/10.1021/i200016a005
  6. Lee, W. J., and Kim, S. D., "Catalytic Activity of Alkali and Transition Metal Salt Mixtures for Steam-char Gasification," Fuel, 74(9), 1387-1393 (1995). https://doi.org/10.1016/0016-2361(95)00081-F
  7. Brooks, J. D., Taylor, G., and Walker Jr, P. L., "Chemistry and Physics of Carbon, Marcel Dekker," New York, 4, 243 (1968).
  8. Mochida, I., and Sakanishi, K., "Catalysts for Coal Convertsions of the Next Generation," Fuel, 79(3), 221-228 (2000). https://doi.org/10.1016/S0016-2361(99)00155-6
  9. Kim, S. C., Kim, U., and Ju, H., "Status and Principle of Coal Integrated Gasification Combined Cycle," Soc. Air-Cond. Refrig., 7, 883-886 (2011).
  10. Song, B., Kang, S., and Kim, S., "Catalytic Activity of K-Fe, Na-Fe, Na-Fe-Ca Mixtures on Char-Steam Gasification," Korean J. Chem. Eng., 30(6), 749-759 (1992).
  11. McKee, D. W., Spiro, C. L., Kosky, P. G., and Lamby, E. J., "Catalysis of Coal Char Gasification by Alkali Metal Salts," Fuel, 62(2), 217-220 (1983). https://doi.org/10.1016/0016-2361(83)90202-8
  12. Sams, D. A., Talverdian, T., and Shadman, F., "Kinetics of Catalyst Loss during Potassium-catalysed $CO_2$ Gasification of Carbon," Fuel, 64(9), 1208-1214 (1985). https://doi.org/10.1016/0016-2361(85)90176-0
  13. Li, S., and Cheng, Y., "Catalytic Gasification of Gas-coal Char in $CO_2$," Fuel, 74(3), 456-458 (1995). https://doi.org/10.1016/0016-2361(95)93482-S
  14. Aranda, A., Murillo, R., Garcia, T., Callen, M., and Mastral, A., "Steam Activation of Tyre Pyrolytic Carbon Black: Kinetic Study in a Thermobalance," Chem. Eng. J., 126(2), 79-85 (2007). https://doi.org/10.1016/j.cej.2006.08.031
  15. Wen, C., "Noncatalytic Heterogeneous Solid-fluid Reaction Models," Ind. Eng. Chem., 60(9), 34-54 (1968).
  16. Ishida, M., and Wen, C. "Comparison of Kinetic and Diffusional Models for Solid-gas Reactions," AIChE J., 14(2), 311-317 (1968). https://doi.org/10.1002/aic.690140218
  17. Kasaoka, S., Sakata, Y., and Tong, C., "Kinetic Evaluation of the Reactivity of Various Coal Chars for Gasification with Carbon Dioxide in Comparison with Steam," Int. Chem. Eng.; (United States), 25(1), (1985).
  18. Howard, J., and Elliott, M., "Chemistry of Coal Utilization," 2nd Suppl. Vol, (1981).
  19. Wen, W. Y., "Mechanisms of Alkali Metal Catalysis in the Gasification of Coal, Char, or Graphite," Catal. Rev., 22(1), 1-28 (1980). https://doi.org/10.1080/03602458008066528
  20. Wood, B. J., Fleming, R. H., and Wise, H., "Reactive Intermediate in the Alkali-carbonate-catalysed Gasification of Coal Char," Fuel, 63(11), 1600-1603 (1984). https://doi.org/10.1016/0016-2361(84)90234-5
  21. Irfan, M. F., Usman, M. R., and Kusakabe, K., "Coal Gasification in $CO_2$ Atmosphere and Its Kinetics Since 1948: A Brief Review," Energy, 36(1), 12-40 (2011). https://doi.org/10.1016/j.energy.2010.10.034
  22. Adjorlolo, A. A., and Rao, Y. K., "Effect of Potassium and Sodium Carbonate Catalysts on the Rate of Gasification of Metallurgical Coke," Carbon, 22(2), 173-176 (1984). https://doi.org/10.1016/0008-6223(84)90207-0
  23. Kopyscinski, J., Rahman, M., Gupta, R., Mims, C. A., and Hill, J. M., "$K_2CO_3$ Catalyzed $CO_2$ Gasification of Ash-free Coal. Interactions of the Catalyst with Carbon in $N_2$ and $CO_2$ Atmosphere," Fuel, 117, 1181-1189 (2013).
  24. Matsuoka, K., Yamashita, T., Kuramoto, K., Suzuki, Y., Takaya, A., and Tomita, A., "Transformation of Alkali and Alkaline Earth Metals in Low Rank Coal during Gasification," Fuel, 87(6), 885-893 (2008). https://doi.org/10.1016/j.fuel.2007.05.031
  25. Dutta, S., Wen, C., and Belt, R., "Reactivity of Coal and Char. 1. In Carbon Dioxide Atmosphere," Ind. Eng. Chem. Process Des. Dev., 16(1), 20-30 (1977). https://doi.org/10.1021/i260061a004
  26. Ergun, S., "Kinetics of the Reaction of Carbon with Carbon Dioxide," J. Phys. Chem., 60(4), 480-485 (1956). https://doi.org/10.1021/j150538a022

Cited by

  1. Reactivity Study on the Kideco Coal Catalytic Coal Gasification under CO2Atmosphere Using Gas-Solid Kinetic Models vol.21, pp.1, 2015, https://doi.org/10.7464/ksct.2015.21.1.053
  2. Drying Characteristics of High Moisture Low Rank Coal using a Steam Fluidized-bed Dryer vol.20, pp.3, 2014, https://doi.org/10.7464/ksct.2014.20.3.321
  3. Kinetic of Catalytic CO2Gasification for Cyprus Coal by Gas-Solid Reaction Model vol.53, pp.5, 2015, https://doi.org/10.9713/kcer.2015.53.5.653

Acknowledgement

Supported by : 한국에너지기술연구원