(463c) Fluidized Bubbling Bed Reactor Model For Silane Pyrolysis In Solar Grade Silicon Production

A reactor model is developed to treat the simultaneous CVD and gas-phase nucleation of solid fines in a fluidized bed reactor for saline pyrolysis. The model distinguishes between the bubble and emulsion region of the bed and are based on the two-phase bubbling fluidized bed model. A gas-phase reaction, resulting in the formation of a supersaturated vapor of the nucleating species, homogenous nucleation, a CVD reaction on surfaces of existing solid particles and the relevant diffusion processes are accounted for. The population balance is used to predict the size distribution of fines and the growth of large particles is ascribed to CVD and capture of fines. Reasonable agreement between predictions and experimental data available in the literatures is established. This model improves our understanding of this process and provides a tool for the optimization of reactor design and operating parameters.