Reactivity of oil shale ashes in the binding of SO2

  • T. Kaljuvee
  • M. Toom
  • A. Trikkel
  • R. Kuusik


The extensive use of fossil fuels in energy production causes serious pollution of atmosphere with SO2, CO2, NOx, etc. In Estonia the electricity production is based mainly on the pulverized firing (PF) of low-grade local fuel – Estonian oil shale (EOS) which is characterized by a low calorific value (~9 MJ kg–1) and a high content of mineral matter (65–70%) from which approximately 50% are carbonates. Since 2004, also two boilers based on circulating fluidized bed combustion (CFBC) of EOS are in exploitation.

The present study is focused on the comparative investigation of the efficiency of different ashes collected from different technological points of CFB and PF boilers as sorbents for SO2. The influence of experimental temperature on the SO2-binding characteristics of ashes as well as the possibilities of activation of ashes (grinding, hydration) were investigated. It was shown that the SO2-binding capacity of initial ashes at 700°C and p(SO2)=190 mm Hg was for CFBC ashes 24–30 mg and for PF ashes 10–23 mg SO2 per 100 mg sample, the best binding capacities belonging to economizer ash (ECOA) and electrostatic precipitator ash from the 1st field (PESPA1f), respectively. However, during initial stage of binding the best results were obtained with air pre-heater ash (PHAA) and ESPA1f (both CFBC ashes). Grinding improved the SO2-binding ability, being the most effective in the case of bottom ash (BA) from CFBC and cyclone ash (PCA) from PF – increase in binding capacity 2 and 2.3 times, respectively. As compared to initial CFBC ashes, the binding characteristics of PF ashes remained lower even after grinding. Hydration and previous calcination improved the binding characteristics only of PF ashes. Hereby, the SO2-binding ability of CFBC ashes is better than of PF ashes and they are more promising sorbents for acidic gases, for example, for sulphur dioxide.


circulating fluidized bed combustion oil shale pulverized firing sulphur dioxide capture waste ashes 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    A. Ots, Oil Shale Combustion Technology, Tallinn 2004, p. 768 [in Estonian].Google Scholar
  2. 2.
    A. Ots, H. Arro and L. Jovanovic, The Behaviour of Inorganic Matter of Solid Fuels during Combustion. Fouling and Corrosion in Steam Boilers; Beograd 1980, p. 276.Google Scholar
  3. 3.
    Kikas, V 1997International Cement-Lime-Gypsum50112Google Scholar
  4. 4.
    Jozewics, W, Chang, JCS, Sedman, CB, Brna, TG 1988Reactivity of Solids6243CrossRefGoogle Scholar
  5. 5.
    Karatepe, N, Ersoy-Merişboyu, A, Demirler, U, Küşükbayrak, S 1998Thermochim. Acta319171CrossRefGoogle Scholar
  6. 6.
    Fernándes, J, Renedo, MJ, Pesquera, A, Irabien, JA 2001Powder Technol.119201CrossRefGoogle Scholar
  7. 7.
    Galos, KA, Smakowski, TS, Szlugaj, J 2003Appl. Energy75257CrossRefGoogle Scholar
  8. 8.
    Lee, KT, Bhatia, S, Mohamed, AR 2005J. Therm. Anal. Cal.79691CrossRefGoogle Scholar
  9. 9.
    Lee, KT, Bhatia, S, Mohamed, AR, Chu, KH 2006Chemosphere6289CrossRefGoogle Scholar
  10. 10.
    Kaljuvee, T, Trikkel, A, Kuusik, R 1997Oil Shale14393Google Scholar
  11. 11.
    Kaljuvee, T, Trikkel, A, Kuusik, R 2001J. Therm. Anal. Cal.641229CrossRefGoogle Scholar
  12. 12.
    Kaljuvee, T, Kuusik, R, Trikkel, A, Bender, V 2005J. Therm. Anal. Cal.80591CrossRefGoogle Scholar
  13. 13.
    Trikkel, A,  et al. 2001Estonian calcareous rocks and oil shale ash as sorbent for SO2. Academic DissertationTTU PressTallinn University of Technology70Google Scholar
  14. 14.
    Kuusik, R, Uibu, M, Kirsimäe, K 2005Oil Shale22407Google Scholar
  15. 15.
    Taylor, JC 1991Powder Diffraction62Google Scholar
  16. 16.
    Colin, RW, Taylor, JC, Cohen, DR 1999J. Sedimentary Res.691050Google Scholar

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  1. 1.Tallinn University of TechnologyTallinnEstonia

Personalised recommendations