Comparisons of Ash Particle Properties Under Air and Oxy Coal Combustion in a 25 kW One-Dimensional Down Fired Furnace

  • G. D. Li
  • S. Q. LiEmail author
  • M. Dong
  • R. L. Axelbaum
  • Q. Yao
Conference paper


A 25 kW one-dimensional down fired furnace was operating in air (O2/N2) and oxy (O2/CO2) combustion conditions respectively. A typical Chinese bituminous coal was burned in this experiment. The furnace operation can be switched between air and oxy conditions freely. The real flue gas recycling was performed but not one through system. The recycle ratio defined as the mass fraction of recycled flue gas to the whole flue gas amount is 77.8% (dry basis) here. Comparisons of ash particle properties under these two different combustion conditions were carried out in this work. The particle matters were sampled in flue gas cooling zone (Port 10) by a self-designed two stages nitrogen dilution water cooled sampling probe. The fly ash particle size distribution results measured by mastersizer 2000 show that the fly ash formed under oxy combustion condition is smaller than those formed under air combustion condition. The elements mass fraction of PM1 show different characteristics under these two conditions. The microscopic analysis confirm differences between air and oxy coal combustion considering burning bulk atmosphere, heat transfer, molecule diffusion and radiation.


Oxy combustion Bituminous coal Fly ash Burn out Microscopic analysis 



This work was supported by the National Natural Science Foundation of China (NSFC) International Research Project (No. 50711130637) and the Special Financial support from Washington University in Saint Louis.


  1. 1.
    Payne R, Chen SL, Wolsky AM, Richter WF. CO2 recovery via coal combustion in mixtures of oxygen and recycled flue gas. Combust Sci Technol. 1989;67:1–16.CrossRefGoogle Scholar
  2. 2.
    Tan YW, Croiset E, Douglas AM, Thambimuthu KV. Combustion characteristics of coal in a mixture of oxygen and recycled flue gas. Fuel. 2006;85:507–12.CrossRefGoogle Scholar
  3. 3.
    Sheng CD, Li Y. Experimental study of ash formation during pulverized coal combustion in O2/CO2 mixtures. Fuel. 2008;87:1297–305.CrossRefGoogle Scholar
  4. 4.
    Skeen SA, Kumfer BM, Axelbaum RL. Nitric oxides emissions during coal and coal/biomass combustion under air-fired and oxy-fuel conditions. Energy Fuel. 2010;24:4144–52.CrossRefGoogle Scholar
  5. 5.
    Zheng LG, Furimsky E. Assessment of coal combustion in O2 + CO2 by equilibrium calculations. Fuel Process Technol. 2003;81:23–34.CrossRefGoogle Scholar
  6. 6.
    Buhre BJP, Elliott LK, Sheng CD, Gupta RP, Wall TF. Oxy-fuel combustion technology for coal-fired power generation. Prog Energy Combust Sci. 2005;31:283–307.CrossRefGoogle Scholar
  7. 7.
    Wall T, Liu YH, Spero C, et al. An overview on oxyfuel coal combustion—state of the art research and technology development. Chem Eng Res Des. 2009;87:1003–16.CrossRefGoogle Scholar
  8. 8.
    Smart JP, O’Nion P, Riley GS. Radiation and convective heat transfer, and burnout in oxy-coal combustion. Fuel. 2010;89:2468–76.CrossRefGoogle Scholar
  9. 9.
    Molina A, Shaddix CR. Ignition and devolatilization of pulverized bituminous coal particles during oxygen/carbon dioxide coal combustion. Proc Combust Inst. 2007;31:1905–12.CrossRefGoogle Scholar
  10. 10.
    Zhuo JK, Li SQ, Yao Q, Song Q. The progressive formation of submicron particulate matter in a quasi one-dimensional pulverized coal combustor. Proc Combust Inst. 2009;32:2059–66.CrossRefGoogle Scholar
  11. 11.
    Krishnamoorthy G, Veranth JM. Computational modeling of CO/CO2 ratio inside single char particles during pulverized cal combustion. Energy Fuel. 2003;17:1367–71.CrossRefGoogle Scholar
  12. 12.
    Zhuo JK. Experimental investigation on the formation mechanisms of submicron particulate matters during pulverized coal combustion. Ph.D. thesis, Tsinghua University, Beijing China, 2008.Google Scholar
  13. 13.
    Sarofim AF, Howard JB, Padia AS. The physical transformation of the mineral matter in pulverized coal under simulated combustion conditions. Combust Sci Technol. 1977;16(3–6):187–204.CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg & Tsinghua University Press 2013

Authors and Affiliations

  • G. D. Li
    • 1
  • S. Q. Li
    • 1
    Email author
  • M. Dong
    • 1
  • R. L. Axelbaum
    • 2
  • Q. Yao
    • 1
  1. 1.Institute of Thermal EngineeringTsinghua UniversityBeijingChina
  2. 2.Consortium for Clean Coal UtilizationWashington University in Saint LouisSaint LouisUSA

Personalised recommendations