A comparative study of non-isothermal kinetics of decomposition of calcium oxalate monohydrate

A review of the mutual dependence of Arrhenius parameters evaluated by the thermoanalytical study of solid-state reactions: the kinetic compensation effect

Thermal decomposition of struvite and its phase transition.

Is the science of thermal analysis kinetics based on solid foundations?: A literature appraisal

Publisher Summary This chapter discusses the compensation effect in heterogeneous catalysis that expresses the existence of interrelated kinetic behavior within a group of rate processes. The chapter focuses on the interrelation between kinetic characteristics and the chemistry of the participating surface rate processes. The chapter discusses the theoretical models and statistical methods used in the recognition of compensation phenomena. The chapter illustrates reported examples of compensation behavior and describes new instances of the effect that became apparent while making the present search of published kinetic data. A semiquantitative statistical analysis of these trends has been undertaken to provide a common basis for comparisons and to attempt to define criteria that enable meaningful relationships to be recognized. The compensation effect remains largely an empirical method of classifying kinetic observations and this has not been developed into a theoretical representation capable of predicting activities and patterns of reactivity in hitherto untested catalytic processes. Development of the usefulness of the correlation necessarily requires reexamination of many of the basic tenets of heterogeneous kinetic behavior.

Compensation Effect in Heterogeneous Catalysis

Fifteen thermogravimetric curves of the thermal decomposition of CaCO3 reported in the literature have been analysed and kinetic parameters have been derived by means of Coats and Redfern's method. The activation energy varies between 26 and 377 kcal/mole, and the pre-exponential factors between 102 and 1069, as functions of the working conditions. The kinetic compensation effect has been observed, and the results are well described by the following empirical compensation law: logZ=0.195E− 1.86.RésuméOn a calculé les paramètres cinétiques de la décomposition thermique de CaCO3 en suivant la méthode de Coats et Redfern et en utilisant 15 courbes thermogravimétriques publiées dans la littérature. L'énergie d'activation varie entre 26 et 377 kcal/mol, les fac teurs préexponentiels entre 102 et 1069, suivant les conditions opératoires. On a observé l'effet de compensation cinétique et les résultats peuvent être décrits par la loi empirique suivante: logZ=0.195E − 1.86.ZusammenfassungFünfzehn, in der Literatur veröffentlichte thermogravimetrische Kurven der thermischen Zersetzung des CaCO3 wurden analysiert und kinetische Parameter unter Anwendung der Methode von Coats und Redfern abgeleitet. Die Aktivierungsenergie schwankt zwischen 26 und 377 kcal/Mol, die prä-exponentiellen Faktoren zwischen 102 und 1069, je nach den Arbeitsbedingungen. Der kinetische Kompensationseffekt wurde beobachtet und die Ergebnisse lassen sich mit dem folgenden empirischen Kompensationsgesetz gut beschreiben: logZ=0.195E− 1.86.РезюмеПроанализированы 15 те рмогравиметрически х кривых термораспада СаСО3, опубликованных в литературе, и по мето ду Котса и Редферна рассчитан ы кинетические параметры в зависимо сти от условий экспер имента. Энергия активации ко леблется между 26 и 377 ккал/мол, преэ кспоненциальные фак торы —между 102 и 1069. Наблю дается эффект кинетической компенсации и резуль таты удовлетворительно о писываются следующим эмпиричес ким законом компенса ции: logZ=0,195E − 1,86.

J. Zsakó

Papers

Kinetic analysis of thermogravimetric data: VII. Thermal decomposition of calcium carbonate