Effect of fluorine on the gasification rate of liquid boron oxide droplets

A model is developed for the chemically facilitated gasification of a liquid boron oxide droplet in high temperature environments with equilibrium species containing the elements O, H, C, and F. The model includes a detailed gas-phase reaction mechanism, separate steps for the adsorption and desorption of gas-phase species at the surface, and multicomponent molecular diffusion. Predictions of the gasification rates are presented for droplets of different diameter and environments with different temperature and composition. Of particular interest is the effect of fluorine on the gasification rate. In addition, model calculations are analyzed with reaction flux and gradient sensitivity analyses to determine the fastest and rate controlling steps of the gasification process. The results show that addition of fluorine accelerates the gasification process. The degree of enhancement was found to depend upon the temperature and mixture composition of the surrounding gas and the diameter of the droplet.