Determination of the activation energy under isothermal conditions: revisited

Abstract

The kinetic analysis of solid-state processes aims at obtaining fundamental information that can be used for predicting the time evolution of a process within a wide range of conditions. It is an extended belief that the determination of the kinetic parameters from the analysis of curves recorded under isothermal conditions is strongly conditioned by the kinetic model used to fit the experimental data. Thus, much effort is devoted to finding the model that truly describes a process in order to calculate the kinetic parameters with accuracy. In this work, we demonstrate that the value of activation energy determined from kinetic analysis of isothermal curves is independent of the kinetic model used to fit the experimental data and, taking advantage of the underlying reason for this, a method for determining the activation energy with two isothermal curves is proposed.

Thermal Stability and Non-Isothermal Kinetic Analysis of Ethylene–Propylene–Diene Rubber Composite

“…The error was less than 1% between the two methods. These results are largely consistent with the references [46,47].…”

“…These results are largely consistent with the references [47,48]. Figure 5 shows the relationship between ln(β/Tp 2 ) and 1000/T, as well as that between ln(β/Tp) and 1000/T, according to the Kissinger [29] and Augis-Bennett/Boswell methods [45,46], respectively, for determination of the activation energy. Both methods gave approximately equal results within the permissible error.…”

“…The decrease of the activation energy with the addition of lead can be attributed to the increase in the thermal conductivity of the composite sample and the decrease of entanglements in the composite matrix. Figure 5 shows the relationship between ln(β/Tp 2 ) and 1000/T, as well as that between ln(β/Tp) and 1000/T, according to the Kissinger [29] and Augis-Bennett/Boswell methods [45,46], respectively, for determination of the activation energy. Both methods gave approximately equal results within the permissible error.…”

Electrochemical and Gravimetric Study on Corrosion Inhibition of Carbon Steels Exposed to Oilfield Produced Water

“…It is important to mention that the data acquired from the X52 steel indicated the presence of a nonlinear profile, where minor CR values corresponded to high activation energies in the range of 17.0 kJ/mol to 27.7 kJ/mol under flowing media, which were determined from the slopes. When the CR is involved in the activation energy, then the following analysis is taken into consideration [13,43,[45][46][47]:…”

“…When CR is low, then Ea is high; thus, a physisorption is considered. This is indicative to a profound impact on the internal corrosion on X60 and X70 steels exposed to OPW so salty and acidic sour solution because a minimum quantity of Ea should be required to start a rate of the steel dissolution as a result of an initial electrochemical deterioration [45][46][47]. It was reported that the result of Ea obtained from X65 steel exposed to acidic solution was around 21.08 kJ/mol [48].…”