The Physical Kinetics of Reversible Thermal Decomposition
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F49777513%3A23640%2F17%3A43950534" target="_blank" >RIV/49777513:23640/17:43950534 - isvavai.cz</a>
Result on the web
<a href="http://dx.doi.org/10.1007/978-3-319-45899-1_17" target="_blank" >http://dx.doi.org/10.1007/978-3-319-45899-1_17</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1007/978-3-319-45899-1_17" target="_blank" >10.1007/978-3-319-45899-1_17</a>
Alternative languages
Result language
angličtina
Original language name
The Physical Kinetics of Reversible Thermal Decomposition
Original language description
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 microkinetics 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.
Czech name
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Czech description
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Classification
Type
C - Chapter in a specialist book
CEP classification
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OECD FORD branch
10403 - Physical chemistry
Result continuities
Project
<a href="/en/project/LO1402" target="_blank" >LO1402: CENTEM+</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2017
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Book/collection name
Thermal Physics and Thermal Analysis
ISBN
978-3-319-45897-7
Number of pages of the result
22
Pages from-to
363-384
Number of pages of the book
567
Publisher name
Springer International Publishing
Place of publication
Cham, Switzerland
UT code for WoS chapter
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