Combustion behaviour and chemical structure changes of enzyme-treated coal

  • Jiawei Wang
  • Zifeng Sui
  • Yifei Zheng
  • Tao Wang
  • Yongsheng ZhangEmail author
  • Hong Xu
  • Wei-Ping Pan


As one of the technologies for the improvement in coal quality, biological enzyme technology has received much attention. The enzyme product named 3EC was shown to enhance the power plant performance in our previous full-scale test. In this work, its effect on coal was explored. The results indicated that the enzyme product was beneficial in the removal of organic sulphur from coal, and the catalytic action of 3EC on the cleavage of C–C and C–S bonds was proven based on data from the dibenzothiophene decomposition test. Thus, when it was used to treat coal, the CH3-to-CH2 ratio changed from 0.81 to 0.32 with an increase in treatment time, which indicated that some chemical structures in the enzyme-treated coal changed. Because of these structural changes, the combustion behaviour of coal improved, indicated by the increase in the comprehensive combustion index from 2.958 × 106 to 3.113 × 106 %2 min−2 K−3 and the decrease in activation energy from 32.76 to 30.43 kJ mol−1. In addition, the optimum enzyme treatment time should be 4 days to ensure enough reaction time between the enzyme and the coal.


Enzyme Coal Combustion Kinetic analysis Chemical structure 

List of symbols


Ignition temperature


Burnout temperature


Average mass loss rate


Maximum mass loss rate


Comprehensive combustion index


Activation energy



Hydraulic retention time




Fourier transform infrared spectroscopy


Thermogravimetric analysis


Gas chromatograph coupled to an SQ 8T mass spectrometer



This work was supported by Kentucky Economic Development Finance Authority.


  1. 1.
    Potter MC. Bacteria as agents in the oxidation of amorphous carbon. Biospectroscopy. 1908;5(1):47–52.Google Scholar
  2. 2.
    Cohen MS, Gabriele PD. Degradation of Coal by the fungi polyporus versicolor and poria monticola. Appl Environ Microbiol. 1982;44(1):23–7.CrossRefGoogle Scholar
  3. 3.
    Fakoussa RM. Production of water-soluble coal-substances by partial microbial liquefaction of untreated hard coal. Resour Conserv Recycl. 1988;1(3):251–60.CrossRefGoogle Scholar
  4. 4.
    Hofrichter M, Fritsche W. Depolymerization of low-rank coal by extracellular fungal enzyme systems. Appl Microbiol Biotechnol. 1996;46(3):220–5.CrossRefGoogle Scholar
  5. 5.
    Aller Á, Martı́Nez O, Linaje JAD, Méndez R, Morán A. Biodesulphurisation of coal by microorganisms isolated from the coal itself. Fuel Process Technol. 2001;69(1):45–57.CrossRefGoogle Scholar
  6. 6.
    Pandey RA, Raman VK, Bodkhe SY, Handa BK, Bal AS. Microbial desulphurization of coal containing pyritic sulphur in a continuously operated bench scale coal slurry reactor. Fuel. 2005;84(1):81–7.CrossRefGoogle Scholar
  7. 7.
    Gonsalvesh L, Marinov SP, Stefanova M, Carleer R, Yperman J. Organic sulphur alterations in biodesulphurized low rank coals. Fuel. 2012;97(7):489–503.CrossRefGoogle Scholar
  8. 8.
    Sui Z, Zhang Y, Wang T, Xu H, Zhang B, Cohron MG, et al. Full-scale demonstration of enzyme-treated coal combustion for improved energy efficiency and reduced air pollution. Energy Fuels. 2018;32(6):6584–94.CrossRefGoogle Scholar
  9. 9.
    Rossi G. The microbial desulfurization of coal. In: Schippers A, Glombitza F, Sand W, editors. Geobiotechnology II: energy resources, subsurface technologies, organic pollutants and mining legal principles. Berlin: Springer; 2014. p. 147–67.Google Scholar
  10. 10.
    Wang S, Liu S, Sun Y, Jiang D, Zhang X. Investigation of coal components of Late Permian different ranks bark coal using AFM and Micro-FTIR. Fuel. 2017;187:51–7. Scholar
  11. 11.
    Chen Y, Mastalerz M, Schimmelmann A. Characterization of chemical functional groups in macerals across different coal ranks via micro-FTIR spectroscopy. Int J Coal Geol. 2012;104:22–33. Scholar
  12. 12.
    Ibarra J, Muñoz E, Moliner R. FTIR study of the evolution of coal structure during the coalification process. Org Geochem. 1996;24(6):725–35. Scholar
  13. 13.
    Li XG, Ma BG, Li X, Hu ZW, Wang XG. Thermogravimetric analysis of the co-combustion of the blends with high ash coal and waste tyres. Thermochim Acta. 2006;441(1):79–83.CrossRefGoogle Scholar
  14. 14.
    Seggiani M, Vitolo S, Pastorelli M, Ghetti P. Combustion reactivity of different oil-fired fly ashes as received and leached. Fuel. 2007;86(12):1885–91.CrossRefGoogle Scholar
  15. 15.
    Wang CA, Zhang X, Liu Y, Che D. Pyrolysis and combustion characteristics of coals in oxyfuel combustion. Appl Energy. 2012;97(3):264–73.CrossRefGoogle Scholar
  16. 16.
    Huang X, Jiang X, Han X, Hui W. Combustion characteristics of fine- and micro-pulverized coal in the mixture of O2/CO2. Energy Fuels. 2008;22(6):3756–62.CrossRefGoogle Scholar
  17. 17.
    Jiang X, Zheng C, Qiu J, Li J, Liu D. Combustion characteristics of super fine pulverized coal particles. Energy Fuels. 2001;15(5):1100–2.CrossRefGoogle Scholar
  18. 18.
    Shen DK, Gu S, Luo KH, Bridgwater AV, Fang MX. Kinetic study on thermal decomposition of woods in oxidative environment. Fuel. 2009;88(6):1024–30.CrossRefGoogle Scholar
  19. 19.
    Wang C, Wang F, Yang Q, Liang R. Thermogravimetric studies of the behavior of wheat straw with added coal during combustion. Biomass Bioenergy. 2009;33(1):50–6.CrossRefGoogle Scholar
  20. 20.
    Monticello DJ. Biodesulfurization and the upgrading of petroleum distillates [review]. Curr Opin Biotechnol. 2000;11(6):540–6.CrossRefGoogle Scholar
  21. 21.
    Qian W, Xie Q, Huang Y, Dang J, Wang J. Combustion characteristics of semicokes derived from pyrolysis of low rank bituminous coal. Int J Min Sci Technol. 2012;22(5):645–50.CrossRefGoogle Scholar

Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2020

Authors and Affiliations

  1. 1.Key Laboratory of Condition Monitoring and Control for Power Plant Equipment, Ministry of EducationNorth China Electric Power UniversityBeijingPeople’s Republic of China
  2. 2.School of Energy and EnvironmentInner Mongolia University of Science and TechnologyBaotouPeople’s Republic of China

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