Korean Chemical Engineering Research

The Korean Institute of Chemical Engineers (한국화학공학회)
권호 표지
DOI QR코드

DOI QR Code

The Effect of Coal Particle Size on Char-$CO_{2}$ Gasification Reactivity by Gas Analysis

가스분석을 이용한 석탄 입자크기가 촤-$CO_{2}$ 가스화 반응성에 미치는 영향 연구

  • Kim, Yong-Tack (Korea Western Power Co., Ltd.) ;
  • Seo, Dong-Kyun (Department of Mechanical Engineering, Yonsei University) ;
  • Hwang, Jung-Ho (School of Mechanical Engineering and Clean Technology, Yonsei University)
  • 김용택 (연세대학교 대학원 청정공학협동과정) ;
  • 서동균 (연세대학교 기계공학과) ;
  • 황정호 (연세대학교 기계공학과 및 청정공학협동과정)
  • Published : 2011.06.30
Download PDF
⟨ Previous Next ⟩

Abstract

Char gasification is affected by operating conditions such as reaction temperature, reactants gas partial pressure, total system pressure and particle size in addition to chemical composition and physical structure of char. The aim of the present work was to characterize the effect of coal particle size on $CO_{2}$ gasification of chars prepared from two different types of bituminous coals at different reaction temperatures(1,000-$1,400{^{\circ}C}$). Lab scale experiments were carried out at atmospheric pressure in a fixed reactor where heat was supplied into a sample of char particles. When a flow of $CO_{2}$(40 vol%) was delivered into the reactor, the char reacted with $CO_{2}$ and was transformed into CO. Carbon conversion of the char was measured using a real time gas analyzer having NDIR CO/$CO_{2}$ sensor. The results showed that the gasification reactivity increased as the particle size decreased for a given temperature. The sensitivity of the reactivity to particle size became higher as the temperature increases. The size effects became remarkably prominent at higher temperatures and became a little prominent for lower reactivity coal. The particle size and coal type also affected reaction models. The shrinking core model described better for lower reactivity coal, whereas the volume reaction model described better for higher reactivity coal.

촤-가스화 반응은 반응온도, 반응가스 부분압력, 시스템 총 압력, 입자크기 등 운전조건뿐만 아니라 촤의 화학적 조성 및 물리적 구조의 영향을 받는다. 본 연구에서는 두 종류의 역청탄 촤를 이용하여 반응온도 1,000-$1,400{^{\circ}C}$에서 $CO_{2}$ 가스화시 입자크기의 영향을 관찰하였다. 실험실 규모의 고정식 반응기를 이용하여 대기압 하에서 실험을 수행하였으며 반응가스인 $CO_{2}$(40 vol%)가 반응기에 공급되면 촤와 반응하여 CO를 생성하였다. 촤의 탄소 전환율을 측정하기 위하여 비분산적외선 방식의 CO/$CO_{2}$ 센서가 장착된 실시간 가스분석기를 이용하였다. 실험결과 동일한 온도에서 입자크기가 감소할수록 가스화 반응성은 증가하였으며 온도가 증가할수록 반응성에 미치는 입자크기의 영향은 더욱더 크게 증가하였다. 또한 반응성이 낮은 촤에서 입자크기의 영향은 다소 적게 나타났다. 입자크기와 석탄 종류는 반응모델에도 영향을 주었다. Shrinking core model은 반응성이 낮은 석탄을 잘 묘사했으며 반대로 Volume reaction model은 반응성이 높은 석탄을 잘 묘사하였다.

Keywords

References

  1. Ahn, D. H., Gibbs, B. M., Ko, K. H. and Kim, J. J., "Gasification Kinetics of an Indonesian Sub-bituminous Coal-char with $CO_{2}$ at Elevated Pressure," Fuel, 80, 1651-1658(2001). https://doi.org/10.1016/S0016-2361(01)00024-2
  2. Kajitani, S., Hara, S. and Matsuda, H., "Gasification Rate Analysis of Coal Char with a Pressurized Drop Tube Furnace," Fuel, 81, 539-546(2002). https://doi.org/10.1016/S0016-2361(01)00149-1
  3. Ochoa, J., Cassanello, M. C., Bonelli, P. R. and Cukierman, A. L., "$CO_{2}$ Gasification of Argentinean Coal Chars: a Kinetic Characterization," Fuel Processing Technology, 74, 161-176(2001). https://doi.org/10.1016/S0378-3820(01)00235-1
  4. Liu, G., Tate, A. G., Bryant, G. W. and Wall, T. F., "Mathematical Modeling of Coal Char Reactivity with $CO_{2}$ at High Pressures and Temperatures," Fuel, 79, 1145-1154(2000). https://doi.org/10.1016/S0016-2361(99)00274-4
  5. Kajitani, S., Suzuki, N., Ashizawa, M. and Hara, S., "$CO_{2}$ Gasification Rate Analysis of Coal Char in Entrained Flow Coal Gasifier," Fuel, 85, 163-169(2006). https://doi.org/10.1016/j.fuel.2005.07.024
  6. Schmal, M., Monteiro, J. L. F. and Toscani, H., "Gasification of High Ash Content Coals with Steam in a Semibatch Fluidized Bed Reactor," Ind. Eng. Chem. Process Des. Dev., 22(4), 563-570 (1983). https://doi.org/10.1021/i200023a002
  7. Adschiri, T., Shiraha, T., Kojima, T. and Furusawa, T., "Prediction of $CO_{2}$ Gasification Rate of Char in Fluidized Bed Gasifier," Fuel, 65, 1688-1693(1986). https://doi.org/10.1016/0016-2361(86)90270-X
  8. Zhang, L., Huang, J., Fang, Y. and Wang, Y., "Gasification Reactivity and Kinetics of Typical Chinese Anthracite Chars with Steam and $CO_{2}$," Energy Fuels, 20(3), 1201-1210(2006). https://doi.org/10.1021/ef050343o
  9. Molina, A. and Mondragon, F., "Reactivity of Coal Gasification with Steam and CO2," Fuel, 77(15), 1831-1839(1998). https://doi.org/10.1016/S0016-2361(98)00123-9
  10. Kim, T. Y., Seo, D. K. and Hwang, J. H., "Characteristics of Various Ranks of Coal Gasification with $CO_{2}$ by Gas Analysis," KOSCO, 15(2), 41-49(2010).
  11. Yasyerli, N., Dogu, T., Dogu, T. and Ar, I., "Deactivation Model for Textural Effects on Kinetics of Gas-solid Noncatalytic Reactions Char Gasification with $CO_{2}$," Chem. Eng. Sci., 51(11), 2523- 2528(1996). https://doi.org/10.1016/0009-2509(96)00104-2
  12. Liu, H., Kaneko, M., Luo, C., Kato, S. and Kojima, T., "Effect of Pyrolysis Time on the Gasification Reactivity of Char with $CO_{2}$ at Elevated Temperatures," Fuel, 83, 1055-1061(2004). https://doi.org/10.1016/S0016-2361(03)00142-X
  13. Liu, H., Luo, C., Toyota, M., Kato, S., Uemiya, S., Kojima, T. and Tominaga, H., "Mineral Reaction and Morphology Change During Gasification of Coal in $CO_{2}$ at Elevated Temperatures," Fuel, 82, 523-530(2003). https://doi.org/10.1016/S0016-2361(02)00292-2
  14. Ye, D. P., Agnew, J. B. and Zhang, D. K., "Gasification of a South Australian low-rank Coal," Fuel, 77(11), 1209-1219(1998). https://doi.org/10.1016/S0016-2361(98)00014-3
  15. Seo, D. K., Lee, S. K., Kang, M. W., Hwang, J. H. and Yu, T. U., "Gasification Reactivity of Biomass Chars with $CO_{2}$," Biomass and Bioenergy, doi:10.1016/j.biombioe. 2010.08.008(2010).
  16. Gmez-Barea, A., Ollero, P. and Fernndez-Baco, C., "Diffusional Effects in $CO_{2}$ Gasification Experiments with Single Biomass Char Particles. 1. Experimental Investigation," Energy and Fuels, 26, 2202-2210(2006).
  17. Souza-Santos, M. L., "Comprehensive Modelling and Simulation of Fluidized Bed Boilers and Gasifiers," Fuel, 68, 1507-1521 (1989). https://doi.org/10.1016/0016-2361(89)90288-3

Cited by

  1. Catalytic Gasification of an Indonesian lignite vol.52, pp.4, 2014, https://doi.org/10.9713/kcer.2014.52.4.544
  2. Gasification Reaction at Various temperature vol.53, pp.6, 2015, https://doi.org/10.9713/kcer.2015.53.6.746
  3. A study on the direct catalytic steam gasification of coal for the bench-scale system vol.34, pp.10, 2017, https://doi.org/10.1007/s11814-017-0167-1
  4. 기-고체 반응 모델을 이용한 Kideco탄의 이산화탄소 촉매 석탄가스화 반응 특성 vol.21, pp.1, 2015, https://doi.org/10.7464/ksct.2015.21.1.053
  5. 석탄을 사용한 CO가스 제조를 위한 CO2 전환기술 vol.32, pp.4, 2015, https://doi.org/10.12925/jkocs.2015.32.4.712