Boron Combustion Model Development with Kinetic Sensitivity Analysis and Measurement of Key Chemical Rate Parameters.

摘要

This report presents kinetics models for the chemically facilitated gasification of the ubiguitous boron oxide coating that inhibits particulate boron ignition and the second stage high temperature boron surface burning that occurs once the oxide coating has been removed. These models include a homogeneous gas phase oxidation mechanism consisting of 19 chemical species and 58 forward and reverse elementary reactions, multicomponent gas phase diffusion and heterogeneous reactions between gas phase oxidation products and the boron oxide/boron surface. Kinetic mechanisms are formulated to describe the heterogeneous surface reactions for both B2O3(1) and B(s) surfaces in terms of simple adsorption and desorption reaction steps. Thermochemical parameters for these reaction steps are estimated from the current heats of formation and gas phase bond energies for the major reactants. Reaction rate parameters are estimated from available experimental data or using elementary transition state theory arguments.