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 equil ibrium species containing the elements O, H, C, and F. The model inclu des a detailed gas-phase reaction mechanism, separate steps for the ad sorption and desorption of gas-phase species at the surface, and multi component molecular diffusion. Predictions of the gasification rates a re presented for droplets of different diameter and environments with different temperature and composition. Of particular interest is the e ffect of fluorine on the gasification rate. In addition, model calcula tions are analyzed with reaction flux and gradient sensitivity analyse s to determine the fastest and rate controlling steps of the gasificat ion process. The results show that addition of fluorine accelerates th e gasification process. The degree of enhancement was found to depend upon the temperature and mixture composition of the surrounding gas an d the diameter of the droplet. (C) 1998 by The Combustion Institute.