Effects of minerals containing sodium, calcium, and iron on oxy-fuel combustion reactivity and kinetics of Zhundong coal via synthetic coal

  • Chang’an WangEmail author
  • Lin Zhao
  • Maobo Yuan
  • Yongbo Du
  • Chenzhao Zhu
  • Yinhe Liu
  • Defu Che


The greatly high contents of alkali and alkali earth metals in Zhundong coal have a negative impact on the combustion and utilization of the coal, which results in serious fouling and slagging problems. In the present study, the influences of different minerals on the oxy-fuel combustion of Zhundong coal via synthetic coal were investigated by thermal analysis, and two isoconversional methods were applied to conduct the kinetic analysis. Additive minerals with single metallic elements including sodium (NaCl, NaCO3, NaAlSi3O8), calcium (CaCl2, CaCO3, CaSO4), and iron (Fe2O3, Fe3O4 and FeS2) rather than complex mixtures were added into synthetic coal to avoid the combined catalysis among various minerals. The experimental results show that the thermogravimetric and derivative thermogravimetric curves of synthetic coals under oxy-fuel conditions are similar to those of Zhundong coals. Most of selected additive minerals affect the ignition temperature slightly (less than 10 °C) but tend to lower the burnout temperature (5–25 °C), which narrows the main combustion temperature zone. The addition of CaCl2 raises the burnout temperature from 645.4 to 689.5 °C and drives down the average combustion rate from 4.44 to 3.83% min−1, while other minerals exhibit negative correlation with the maximum and average combustion rates in most cases. The reaction kinetics analysis indicates that the apparent activation energy of coal combustion depends heavily on the category of additive minerals, which varies from 21.31 to 39.05 kJ mol−1 (average values calculated by KAS method). Besides, the apparent activation energy declines with an increase in the conversion rate of samples.


Zhundong coal Oxy-fuel combustion Synthetic coal Thermogravimetic analysis Kinetic analysis 



The authors acknowledge financial support from the National Natural Science Foundation of China (51506163), the Key Laboratory of Renewable Energy Electric-Technology of Hunan Province (Changsha University of Science & Technology) and the China Postdoctoral Science Foundation (2018M641885).


  1. 1.
    BP statistical review of world energy 2018. In: BP statistical review of world energy. BP p.l.c. 2018. Accessed 1 Dec 2018
  2. 2.
    Gao YX, Ding LZ, Li X, Wang WH, Xue Y, Zhu XQ, Hu HY, Luo GQ, Naruse I, Bai ZQ, Yao H. Na&Ca removal from Zhundong coal by a novel CO2-water leaching method and the ashing behavior of the leached coal. Fuel. 2017;210:8–14.Google Scholar
  3. 3.
    Ding LZ, Gao YX, Li X, Wang WH, Xue Y, Zhu XQ, Xu K, Hu HY, Luo GQ, Naruse I, Yao H. A novel CO2-water leaching method for AAEM removal from Zhundong coal. Fuel. 2019;237:786–92.Google Scholar
  4. 4.
    Yang YP, Lin XC, Chen XJ, Wang YG, Gao L, Chen LJ. The formation of deposits and their evolutionary characteristics during pressurized gasification of Zhundong coal char. Fuel. 2018;224:469–80.Google Scholar
  5. 5.
    Wang CA, Li GY, Du YB, Yan Y, Li H, Che DF. Ash deposition and sodium migration behaviors during combustion of Zhundong coals in a drop tube furnace. J Energy Inst. 2018;91(2):251–61.Google Scholar
  6. 6.
    Wang CA, Zhu X, Liu X, Lv Q, Zhao L, Che DF. Correlations of chemical properties of high-alkali solid fuels: a comparative study between Zhundong coal and biomass. Fuel. 2018;211:629–37.Google Scholar
  7. 7.
    Yoshiie R, Hikosaka N, Nunome Y, Ueki Y, Naruse I. Effects of flue gas re-circulation and nitrogen contents in coal on NOX emissions under oxy-fuel coal combustion. Fuel Process Technol. 2015;136:106–11.Google Scholar
  8. 8.
    Stanger R, Wall T, Spörl R, Paneru M, Grathwohl S, Weidmann M, Scheffknecht G, Mcdonald D, Myöhänen K, Ritvanen J, Rahiala S, Hyppänen T, Mletzko J, Kather A, Santos S. Oxyfuel combustion for CO2 capture in power plants. Int J Greenh Gas Control. 2015;40:55–125.Google Scholar
  9. 9.
    Wang CA, Zhang YH, Wang PQ, Zhang JP, Du YB, Che DF. Effects of silicoaluminate oxide and coal blending on combustion behaviors and kinetics of zhundong coal under oxy-fuel condition. J Therm Anal Calorim. 2018;134(3):1975–86.Google Scholar
  10. 10.
    Bu Y, Dai X, Lu P. Release characteristics of semi-volatile heavy metals during co-combustion of sewage sludge and coal under the O2/CO2 atmosphere. J Therm Anal Calorim. 2018;133(2):1041–7.Google Scholar
  11. 11.
    Song GL, Yang SB, Song WJ, Qi XB. Release and transformation behaviors of sodium during combustion of high alkali residual carbon. Appl Therm Eng. 2017;122:285–96.Google Scholar
  12. 12.
    Jin H, Chen YA, Ge ZW, Liu SK, Ren CS, Guo LJ. Hydrogen production by Zhundong coal gasification in supercritical water. Int J Hydrog Energy. 2015;40(46):16096–103.Google Scholar
  13. 13.
    Zhang XP, Zhang C, Tan P, Li X, Fang QY, Chen G. Effects of hydrothermal upgrading on the physicochemical structure and gasification characteristics of Zhundong coal. Fuel Process Technol. 2018;172:200–8.Google Scholar
  14. 14.
    Ge HJ, Shen LH, Gu HM, Song T, Jiang SX. Combustion performance and sodium transformation of high-sodium ZhunDong coal during chemical looping combustion with hematite as oxygen carrier. Fuel. 2015;159:107–17.Google Scholar
  15. 15.
    Ge HJ, Shen LH, Gu HM, Song T, Jiang SX. Combustion performance and sodium absorption of ZhunDong coal in a CLC process with hematite oxygen carrier. Appl Therml Eng. 2016;94:40–9.Google Scholar
  16. 16.
    Liu YZ, He Y, Wang ZH, Xia J, Wan KD, Whiddon R, Cen KF. Characteristics of alkali species release from a burning coal/biomass blend. Appl Energy. 2018;215:523–31.Google Scholar
  17. 17.
    Ma XW, Li FH, Ma MJ, Fang YT. Fusion characteristics of blended ash from Changzhi coal and biomass. J Fuel Chem Technol. 2018;46(2):129–37.Google Scholar
  18. 18.
    Li JB, Zhu MM, Zhang ZZ, Zhang K, Shen GQ, Zhang DK. Characterisation of ash deposits on a probe at different temperatures during combustion of a Zhundong lignite in a drop tube furnace. Fuel Process Technol. 2016;144:155–63.Google Scholar
  19. 19.
    Du XS, Yang GP, Chen YR, Ran JY, Zhang L. The different poisoning behaviors of various alkali metal containing compounds on SCR catalyst. Appl Surf Sci. 2017;392:162–8.Google Scholar
  20. 20.
    Xu JY, Yu DX, Fan B, Zeng XP, Lv WZ, Chen J. Characterization of ash particles from co-combustion with a Zhundong coal for understanding ash deposition behavior. Energy Fuels. 2014;28(1):678–84.Google Scholar
  21. 21.
    Li JB, Zhu MM, Zhang ZZ, Zhang K, Shen GQ, Zhang DK. Effect of coal blending and ashing temperature on ash sintering and fusion characteristics during combustion of Zhundong lignite. Fuel. 2017;195:131–42.Google Scholar
  22. 22.
    Arenillas A, Pevida C, Rubiera F, Pis JJ. Comparison between the reactivity of coal and synthetic coal models. Fuel. 2003;82(15):2001–6.Google Scholar
  23. 23.
    Wang CA, Du YB, Che DF. Reactivities of coals and synthetic model coal under oxy-fuel conditions. Thermochim Acta. 2013;553:8–15.Google Scholar
  24. 24.
    Ruan RH, Xiao JF, Du YL, Tan HZ, Wang XB, Yang FX. Effect of interaction between sodium and oxides of silicon and aluminum on the formation of fine particulates during synthetic char combustion. Energy Fuels. 2018;32(6):6756–62.Google Scholar
  25. 25.
    Pevida C, Arenillas A, Rubiera F, Pis JJ. Heterogeneous reduction of nitric oxide on synthetic coal chars. Fuel. 2005;84(17):2275–9.Google Scholar
  26. 26.
    Pevida C, Arenillas A, Rubiera F, Pis JJ. Synthetic coal chars for the elucidation of NO heterogeneous reduction mechanisms. Fuel. 2007;86(1):41–9.Google Scholar
  27. 27.
    Ertunc G, Kok MV. Determination of kinetic parameters of different origin coals using software. J Therm Anal Calorim. 2015;119(2):1407–13.Google Scholar
  28. 28.
    Jayaraman K, Kok MV, Gokalp I. Combustion properties and kinetics of different biomass samples using TG–MS technique. J Therm Anal Calorim. 2016;127(2):1361–70.Google Scholar
  29. 29.
    Xin HH, Wang DM, Qi XY, Zhong XX, Ma LY, Dou GL, Wang HT. Oxygen consumption and chemisorption in low-temperature oxidation of sub-bituminous pulverized coal. Spectrosc Lett. 2018;51(2):104–11.Google Scholar
  30. 30.
    Zhong XX, Kan L, Xin HH, Qin BT, Dou GL. Thermal effects and active group differentiation of low-rank coal during low-temperature oxidation under vacuum drying after water immersion. Fuel. 2019;236:1204–12.Google Scholar
  31. 31.
    Gundogar AS, Kok MV. Thermal characterization, combustion and kinetics of different origin crude oils. Fuel. 2014;123:59–65.Google Scholar
  32. 32.
    Dong ZJ, Cai JM. Isoconversional kinetic analysis of sweet sorghum bagasse pyrolysis by modified logistic mixture model. J Energy Inst. 2018;91(4):513–8.Google Scholar
  33. 33.
    Jayaraman K, Kok MV, Gokalp I. Thermogravimetric and mass spectrometric (TG-MS) analysis and kinetics of coal-biomass blends. Renew Energy. 2017;101:293–300.Google Scholar
  34. 34.
    Ozbas KE, Kok MV, Hicyilmaz C. Comparative kinetic analysis of raw and cleaned coals. J Therm Anal Calorim. 2002;69(2):541–9.Google Scholar
  35. 35.
    Altun NE, Hicyilmaz C, Kok MV. Effect of different binders on the combustion properties of lignite—part I. Effect on thermal properties. J Therm Anal Calorim. 2001;65(3):787–95.Google Scholar
  36. 36.
    Altun NE, Kok MV, Hicyilmaz C. Effect of different binders on the combustion properties of lignite. Part II. Effect on kinetics. J Therm Anal Calorim. 2001;65(3):797–804.Google Scholar
  37. 37.
    Babinski P, Sciazko M, Ksepko E. Limitation of thermogravimetry for oxy-combustion analysis of coal chars. J Therm Anal Calorim. 2018;133(1):713–25.Google Scholar
  38. 38.
    Biswas S, Choudhury N, Sarkar P, Mukherjee A, Sahu SG, Boral P, Choudhury A. Studies on the combustion behaviour of blends of Indian coals by TGA and drop tube furnace. Fuel Process Technol. 2006;87(3):191–9.Google Scholar
  39. 39.
    Lu Z, Maroto Valer MM, Schobert HH. Catalytic effects of inorganic compounds on the development of surface areas of fly ash carbon during steam activation. Fuel. 2010;89(11):3436–41.Google Scholar
  40. 40.
    Li H, Lin Q. Effect of alkaline, alkaline-earth and transition metals on catalytic oxidation of coals. J Dalian Univ Technol. 1989;03:289–94.Google Scholar
  41. 41.
    Tang YB. Experimental investigation of applying MgCl2 and phosphates to synergistically inhibit the spontaneous combustion of coal. J Energy Inst. 2018;91(5):639–45.Google Scholar
  42. 42.
    Slovák V, Taraba B. Urea and CaCl2 as inhibitors of coal low-temperature oxidation. J Therm Anal Calorim. 2012;110(1):363–7.Google Scholar
  43. 43.
    Tang YB, Li ZH, Yang YI, Ma DJ, Ji HJ. Effect of inorganic chloride on spontaneous combustion of coal. J South Afr Inst Min Metall. 2015;115(2):87–92.Google Scholar
  44. 44.
    Wei L, Jiang X, Li A, Yang T, Li Y. Influence of mineral matter on combustion character in micro-pulverized coal during combustion. Proc CSEE. 2007;08:5–10.Google Scholar
  45. 45.
    He XJ, Zhang JL, Qi CL, Kong DW, Ma C, Lu WJ. Kinetic analysis and effect of catalysts on combustion characteristics of pulverized coal. Iron Steel. 2012;47(07):74–9.Google Scholar
  46. 46.
    Dong Z, Cai J. Isoconversional kinetic analysis of sweet sorghum bagasse pyrolysis by modified logistic mixture model. J Energy Inst. 2018;91(4):513–8.Google Scholar
  47. 47.
    Kok MV, Topa E. Thermal characterization and model-free kinetics of biodiesel sample. J Therm Anal Calorim. 2015;122(2):955–61.Google Scholar
  48. 48.
    Kök MV, Varfolomeev MA, Nurgaliev DK. Isoconversional methods to determine the kinetics of crude oils-thermogravimetry approach. J Petrol Sci Eng. 2018;167:480–5.Google Scholar
  49. 49.
    Varfolomeev MA, Nagrimanov RN, Galukhin AV, Vakhin AV, Solomonov BN, Nurgaliev DK, Kok MV. Contribution of thermal analysis and kinetics of Siberian and Tatarstan regions crude oils for in situ combustion process. J Therm Anal Calorim. 2015;122(3):1375–84.Google Scholar

Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2019

Authors and Affiliations

  • Chang’an Wang
    • 1
    Email author
  • Lin Zhao
    • 1
  • Maobo Yuan
    • 1
  • Yongbo Du
    • 1
  • Chenzhao Zhu
    • 1
  • Yinhe Liu
    • 1
  • Defu Che
    • 1
  1. 1.State Key Laboratory of Multiphase Flow in Power Engineering, School of Energy and Power EngineeringXi’an Jiaotong UniversityXi’anPeople’s Republic of China

Personalised recommendations