Aims and methods in non-isothermal reaction kinetics

Abstract

The majority of the works dealing with non-isothermal kinetics assumes only one kinetic differential equation, uses linearization techniques and do not check the fit between the simulated and the experimental data. It is not clear from the literature why we need kinetic evaluations at all in this field. Due to this controversial situation, the author has outlined his views on the aims and methods of the non-isothermal kinetics in this paper. Accordingly, the goal of the kinetic evaluation is to obtain better, more informative results from the experiments. If realistic models are used, numerous unknown parameters have to be determined during the evaluation. Since the most important errors of thermal analysis are not random, the laws of the mathematical statistics do not offer means to find the best set of model parameters. Nevertheless, the simultaneous evaluation of a series of thermoanalytical experiments by the method of least squares aims directly at the description of the sample behavior in a wide range of experimental conditions and helps the determination of a large number of unknown parameters. The outlined considerations are supported by examples from the work of the author and coworkers. As a comparison, a statistical survey is given on those papers that were published in journals specialized for thermal analysis, thermochemistry and pyrolysis in 2006 and contained the term “kinetic” or “kinetics” in their titles.