Authors:Andrzej Mianowski, Zbigniew Robak, Martyna Tomaszewicz, and Sławomir Stelmach
energy(Δ E ) are used. Often these have positive values that, in a notation of exp(Δ E/RT ), can result in a misunderstanding (a negative value of activationenergy). Using relation ( 17 ) and satisfying condition ( 8 ), one can derive the linear form
-step reaction [ 6 , 7 ], in which the Arrhenius parameters (activationenergy and pre-exponential factor) vary with dehydration degree. Therefore, it's difficult to use a single pair of Arrhenius parameters to reveal the chemical mechanism and to predict the
Authors:B. Hefczyc, T. Siudyga, J. Zawadiak, and A. Mianowski
methods [ 6 – 8 ]. These investigations enable the activationenergies for decomposition, decomposition rate constants at different temperatures, and thermal ranges of decomposition to be determined. The kinetic data enables the conditions of
Authors:Andrzej Mianowski, Izabela Baraniec-Mazurek, and Rafał Bigda
, formulas in forms ( 14 ) and ( 15 ) were used.
Each analysis of compounds (CaC 2 O 4 ·H 2 O and CaCO 3 ) was preceded by determination of activationenergy according to modified Kissinger law in version [ 17 ]:
to confirm whether own data are
heating rates or a set of isothermal measurements with different temperatures. We will consider here the set of different heating rates, because it can be analyzed by all model-free methods.
Model-free analysis allows to find activationenergy of
Authors:Dominique Roberge, Christian Noti, Eberhard Irle, Markus Eyholzer, Bruno Rittiner, Gerhard Penn, Gottfried Sedelmeier, and Berthold Schenkel
After a short section of safety aspects related to 2-nitroethanol, the paper describes a powerful methodology for developing flow processes based on a proof of concept (1), an optimization and modeling analysis (2), and a long run study in a mini-plant (3). The proof of concept is the initial stage where the solubilities and concentrations are fixed, taking into account the rough kinetics with a mass transfer understanding. It is followed by a complete kinetic analysis including activation energy to model the reaction under various conditions to optimize different targets (yield not being the only driver!). The last section shows the operation of a mini-plant including a microreactor and work-up unit operations. The approach is extremely powerful as it enables the study at laboratory scale of all the features that are usually associated with a pilot plant namely: stability over time on stream, solvent recirculation, model prediction, and robustness.
Authors:Lech Nowicki, Anna Antecka, Tomasz Bedyk, Paweł Stolarek, and Stanisław Ledakowicz
-exponential factor and activationenergy, respectively, and n is the reaction order in respect to the concentration of gasifying agent.
Many different functions can be used to describe changes in the physical properties of the solid comprised in the r s
Authors:D. Wyrzykowski, E. Hebanowska, G. Nowak-Wiczk, M. Makowski, and L. Chmurzyński
the case of complex processes, result in a description incompatible with reality; (ii) attempts to determine kinetic parameters of a reaction, i.e. activationenergy, E a , or exponent in the Arrhenius equation (the Friedman or Ozawa
Authors:Juliusz Leszczynski, Krzysztof T. Wojciechowski, and Andrzej Leslaw Malecki
1/2 ( Fig. 15 ) showed that the parabolic law is also well describing the second stage of the oxidation. Activationenergies E a were calculated, assuming the one-dimensional diffusion equation. For the first stage the calculated activationenergy
It is expressed by a decrease of the T g temperature as well as the temperatures of individual stages of crystallization, which is tantamount to a decrease of their activationenergy. A change in the course of crystallization also takes