Advertisement

The Physical Kinetics of Reversible Thermal Decomposition

  • J. CzarneckiEmail author
  • J. Šesták
Chapter
Part of the Hot Topics in Thermal Analysis and Calorimetry book series (HTTC, volume 11)

Abstract

A new theoretical basis, fitting thermal analysis of solids more adequately than the Arrhenius equation developed for reacting gas molecules, is proposed for gas-evolving reversible decompositions. Such complex processes are theoretically dissected into elementary steps, showing distinctions between micro-kinetics and macro-kinetics; only the slowest step being recordable thermoanalytically. Practical procedures of determination whether a thermoanalytical process is controlled by chemical kinetics on micro-level, or by physical macro-processes of heat- and gas-transport in the bulk, based on exposing the samples to changing degrees of heat transfer, and (separately) to the changing degree of exposure to the gaseous decomposition product, are postulated as a prerequisite before choosing the calculation model. It is shown that many typical processes of gas-evolving reversible decomposition are controlled not by chemical micro-kinetics, but by the physical processes of escaping of the gases and of the heat transfer. Even in smallest samples, the overlapping gradients of the temperature and of the gas concentration, plus two or three interwoven reaction fronts, invalidate micro-kinetic calculations and indicate that thermoanalytical data reflect globally the behavior of the sample as a whole, not of its individual grains or molecules—those two classes being completely different. The meaning of decomposition temperature is revisited. A family of TG curves obtained at the specified conditions enables distinguishing between the true decomposition temperature and the procedural one; only the latter being normally recorded. A pitfall of determination of decomposition temperature by CRTA is discussed. Implication for industrial processes are suggested.

Keywords

Gaseous Product Decomposition Temperature Gaseous Decomposition Product Inadequate Equation Incline Section 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

References

  1. 1.
    Ozawa T (1965) A new method of analyzing thermogravimetric data. Bull Chem Soc Japan 38(11):1881–1886. doi: 10.1246/bcsj.38.1881
  2. 2.
    Maciejewski M (2000) Computational aspects of kinetic analysis. Part B: the ICTAC kinetics project—the decomposition kinetics of calcium carbonate revisited, or some tips on survival in the kinetic minefield. Thermochim Acta 355(1–2):145–154CrossRefGoogle Scholar
  3. 3.
    Maciejewski M, Reller A (1987) How (un)reliable are kinetic data of reversible solid-state decomposition processes? Thermochim Acta 110:145–152CrossRefGoogle Scholar
  4. 4.
    Lyahkov NZ, Maciejewski M, Reller A (1985) Theoretical considerations on the temperature and pressure dependence of the kinetics of reversible thermal decomposition processes of solids. J Solid State Chem 58(3):398–400CrossRefGoogle Scholar
  5. 5.
    Maciejewski M, Baldyga J (1985) The influence of the pressure of the gaseous product on the reversible thermal decomposition of solids. Thermochim Acta 92:105–108CrossRefGoogle Scholar
  6. 6.
    Sestak J (1984) Thermophysical properties of solids: theoretical thermal analysis. Elsevier, Amsterdam (Russian translation ‘Těoretičeskij těrmičeskij analyz’. Mir, Moscow 1988) Google Scholar
  7. 7.
    Liptay G (1975) Atlas of thermoanalitycal curves. Akademiai Kiado, BudapestGoogle Scholar
  8. 8.
    Kemula W, Czarnecki J (1978) Mass- and heat transfer approach to reversible thermal decomposition of solids. Pol J Chem 52:613Google Scholar
  9. 9.
    Czarnecki J (1991) Heat- and mass-transfer approach to decomposition kinetics. In: Presented at 19-th annual north american thermal analysis society conference, Boston, MA; published in Solutions for Thermogravimetry. https://goo.gl/ABZX9y. Accessed 1 Dec 2015
  10. 10.
    Garn PD (1972) CRC Crit Rev Anal Chem 172:65Google Scholar
  11. 11.
    Hills AWD (1968) The mechanism of the thermal decomposition of calcium carbonate. Chem Eng Sci 23(4):297–320. doi: 10.1016/0009-2509(68)87002-2 CrossRefGoogle Scholar
  12. 12.
    Rozovskii AY (1974) Kinetika Topo-Khimitsheskikh Reakcii, Izd. Khimija, MoscowGoogle Scholar
  13. 13.
    Garn PD (1965) Thermoanalytical methods of investigation. Academic Press, New YorkGoogle Scholar
  14. 14.
    Czarnecki J (2015) Precision thermogravimetry. J Therm Anal Calorim 120:139–147. doi: 10.1007/s10973-014-4384-0 CrossRefGoogle Scholar
  15. 15.
    Czarnecki J (2014) Procedure for determination of thermodynamic values of thermal stability and decomposition temperature. Solutions for thermogravimetry. https://goo.gl/pQkBFv. Accessed 1 Dec 2015
  16. 16.
    Gray AP (1968) A simple generalized theory for the analysis of dynamic thermal measurement. Analytical Calorimetry, Plenum Press, New YorkCrossRefGoogle Scholar
  17. 17.
    Czarnecki J (2009) The postulated new theoretical model of thermal decomposition that needs to be developed. Solutions for thermogravimetry. https://goo.gl/EHRYy8. Accessed 1 Dec 2015
  18. 18.
    Nikolaev AV, Logvinenko VA (1978) The problem of the utilizability of the starting temperature of thermal decomposition for the evaluation of the thermal stabilities of co-ordination compounds. J Therm Anal 13:253. doi: 10.1007/BF01912297 CrossRefGoogle Scholar
  19. 19.
    Toledo M, Collected applications, thermal analysis, tutorial kit, pp 17–21. https://us.mt.com/dam/Analytical/ThermalAnalysi/TA-PDF/51709920_A_2012_PTFE.pdf (address shortened for typing: https://goo.gl/FN0Zuc), visited 1 Dec 2015
  20. 20.
    Czarnecki J, Koga N, Šestákova V, Šesták J (1992) Factors affecting the experimentally resolved shapes of TG curves. J Therm Anal 38:575–582CrossRefGoogle Scholar
  21. 21.
    Czarnecki J, Sestak J (1915) From recording balances o thermogravietric instruments and back. J Therm Anal 120:157–166. doi: 10.1007/s10973-014-4385-z CrossRefGoogle Scholar
  22. 22.
    Holba P (2015) Ehrenfest equations for calorimetry and dilatometry. J Therm Anal Calorim. doi: 10.1007/s10973-015-4406-6 Google Scholar
  23. 23.
    Czarnecki J, Šesták J (2000) Practical thermogravimetry. J Therm Anal Cal 60(2):759–778CrossRefGoogle Scholar
  24. 24.
    Šesták J (2014) The quandary aspects of non-isothermal kinetics beyond the ICTAC kinetic committee recommendations. Thermochim Acta 611(2015):26–35Google Scholar

Copyright information

© Springer International Publishing Switzerland 2017

Authors and Affiliations

  1. 1.BreaUSA
  2. 2.New Technologies Research Centre (NTC-ZČU)University of West BohemiaPilsenCzech Republic

Personalised recommendations