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:Maria Kulawska, Henryk Moroz, and Aleksandra Kasprzyk
energy has been derived from the Arrhenius plot on the base of mean values of reaction rate constants from experiments at various temperatures.
The values of activationenergy E a and the values of pre-exponential factor k 0 are given in
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