Thermal decomposition of mixed calcium oxalate hydrates - kinetic deconvolution of complex heterogeneous processes

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216275%3A25310%2F20%3A39916414" target="_blank" >RIV/00216275:25310/20:39916414 - isvavai.cz</a>

Výsledek na webu

<a href="https://pubs.rsc.org/en/content/articlelanding/2020/CP/C9CP06867H#!divAbstract" target="_blank" >https://pubs.rsc.org/en/content/articlelanding/2020/CP/C9CP06867H#!divAbstract</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/c9cp06867h" target="_blank" >10.1039/c9cp06867h</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Thermal decomposition of mixed calcium oxalate hydrates - kinetic deconvolution of complex heterogeneous processes

Popis výsledku v původním jazyce

Differential scanning calorimetry (DSC), thermogravimetry (TG) and in situ XRD were used to study dehydration and consequent decomposition reactions of mixed calcium oxalate hydrates. As the complex dehydration kinetics exhibited certain trends with respect to the applied heating rate, the modified multivariate kinetic analysis approach (based on averaged curve-by-curve optimizations) was employed to obtain a full kinetic description of the data. The Sestak-Berggren equation was used to model the two consequent dehydration reactions. Good agreement was found between the kinetic parameters calculated from the DSC and TG data - approximate values of activation energies were 68 and 81 kJ mol(-1) for the trihydrate -&gt; monohydrate and monohydrate -&gt; anhydride transformations, respectively. A procedural methodology was developed to predict both dehydration kinetics and hydrate content ratios. For the calcium oxalate decomposition the TG technique provided very precise single-step prediction with an activation energy of 180 kJ mol(-1). DSC on the other hand provided complex information on joint decomposition and carbon monoxide oxidation reactions - the proposed reaction mechanism includes completion of two reaction paths composed of consequent chemical reactions. A mechanistic view of the complex reaction path is discussed in terms of the diffusion barrier limiting the oxidation step.

Název v anglickém jazyce

Thermal decomposition of mixed calcium oxalate hydrates - kinetic deconvolution of complex heterogeneous processes

Popis výsledku anglicky

Differential scanning calorimetry (DSC), thermogravimetry (TG) and in situ XRD were used to study dehydration and consequent decomposition reactions of mixed calcium oxalate hydrates. As the complex dehydration kinetics exhibited certain trends with respect to the applied heating rate, the modified multivariate kinetic analysis approach (based on averaged curve-by-curve optimizations) was employed to obtain a full kinetic description of the data. The Sestak-Berggren equation was used to model the two consequent dehydration reactions. Good agreement was found between the kinetic parameters calculated from the DSC and TG data - approximate values of activation energies were 68 and 81 kJ mol(-1) for the trihydrate -&gt; monohydrate and monohydrate -&gt; anhydride transformations, respectively. A procedural methodology was developed to predict both dehydration kinetics and hydrate content ratios. For the calcium oxalate decomposition the TG technique provided very precise single-step prediction with an activation energy of 180 kJ mol(-1). DSC on the other hand provided complex information on joint decomposition and carbon monoxide oxidation reactions - the proposed reaction mechanism includes completion of two reaction paths composed of consequent chemical reactions. A mechanistic view of the complex reaction path is discussed in terms of the diffusion barrier limiting the oxidation step.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10403 - Physical chemistry

Projekt

<a href="/cs/project/GA17-11753S" target="_blank" >GA17-11753S: Kinetická analýza komplexních fyzikálně chemických procesů</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2020

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Physical Chemistry Chemical Physics

ISSN

1463-9076

e-ISSN

—

Svazek periodika

22

Číslo periodika v rámci svazku

16

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

13

Strana od-do

8889-8901

Kód UT WoS článku

000537175100062

EID výsledku v databázi Scopus

2-s2.0-85084167373