Determination of chemical kinetic parameters in Arrhenius equation of constant heating rate: Theoretical method

• Published in: Alexandria engineering journal 2023-03, Vol.67, p.461-472
• Main Authors: Youssef, Amr A.-Al, Salas, Alvaro H., Al-Harbi, Nuha, Basfer, N.M., Nassr, Dieaa I.
• Format: Article
• Language: English
• Subjects: 34-XX; 65Kxx; 80-XX; Activation energy; Arrhenius equation; Pre-exponential factor
• ISSN: 1110-0168
• DOI: 10.1016/j.aej.2022.12.046

The article offers a brand-new nonlinear method of figuring out the thermally dissolved material’s free activation energy and pre-exponential factor using a non-isothermal kinetic process. The material is thermally decomposed for a known function in a conversion mass fraction and residual mass fraction under the conditions of the thermochemical reaction, which is defined by the Arrhenius equation. The experimental data establishes a new method based on the least squares method to directly calculate the free activation energy and pre-exponential factor, respectively. We assume that the researcher in a laboratory, during the process of subjecting the material to a constant rate of temperature increase, takes several different measurements for the conversion mass fraction with corresponding values of temperature throughout the process of thermal decomposition of a material. Therefore, in this investigation, we present how to calculate the activation energy and the pre-exponential factor of a material from the information of several points for temperature values during the thermal decomposition process of a material and the corresponding conversion mass fraction. We have discovered that the more measurements we take, the more precise our calculations become. This approach depends on the precise analytical answer to the Arrhenius equation.