IGNITION AND COMBUSTION OF SINGLE SOLID PARTICLES AS NON-ISOTHERMAL METHODS OF CHEMICAL KINETICS

Grigore Ambrosi

doi:10.52326/jes.utm.2021.28(3).04

Abstract

The ignition and combustion of single particles of crystalline boron continue to produce major scientific interest due to the particularities of the process and diversity of potential applications of boron compounds. The full valorization of boron energetic potential is a very current scientific challenge. The objective of the paper is to systematize the methodology for evaluating the kinetic parameters of boron ignition and combustion reactions in various oxidizing gaseous environments. Experimental dependencies between the ignition temperature and the particle size, as well as the combustion time as a function of oxidizing temperature are used for the calculation of the kinetic constants. As a main result, the kinetic parameters of the ignition and combustion reactions of boron in oxygen and water vapor are calculated.

Highlights

The ignition and combustion of single solid particles as non-isothermal methods of formal chemical kinetics contributes to obtaining unique information on the kinetics and thermodynamics of heterogeneous reactions at high temperatures, data that cannot be obtained otherwise, especially for dispersed systems
Based on the principles of formal kinetics, which are a component of general methods of evaluating the kinetic parameters of chemical reactions, particular methods have been deducted for calculating the kinetic constants of complex reactions of ignition and combustion of single solid particles for different regimes of chemical reaction of oxidation
The methodology for evaluating the kinetic parameters of heterogeneous oxidation reactions involves the use of some experimental data as initial data

Summary

Introduction

Approached by Wilhelm Nusselt, the issue of ignition and combustion of the solid particle still requires major attention. Despite an impressive amount of relevant information on this topic and the formulation of remarkable theoretical generalizations, currently there is no irrevocable analytical theory, which considers the complexity of physicochemical phenomena specific to heterogeneous ignition and combustion processes. Chemical kinetics, developed from practical needs to clarify the picture of chemical transformations, especially for the determination of the speed and mechanism of reactions, contributes decisively to the study of ignition and combustion phenomena. The studies of chemical kinetics are combining two complementary directions, both of them having different paradigms and tasks [1]. The objective of the first direction is to identify the mechanism of the reaction This objective is achieved by applying the modern methods of stoichiometry, chemical thermodynamics, theory of solid mechanics and theory of activated complex.

Objectives

Conclusion