Titania formation by TiCl4 gas phase oxidation, surface growth and coagulation

Abstract Titania particle formation by TiCl 4 gas phase oxidation, surface growth and coagulation is investigated by a moving sectional population balance model. The dynamic evolution of the detailed particle size distribution is studied accounting for and neglecting the effect of surface growth. The effects of process temperature, T , and precursor volume fraction, φ , on the average diameter, d p , and geometric standard deviation of the particle size distribution are highlighted. Accounting for surface reaction accelerates particle growth for φ >0.01 and gives a size distribution narrower than the self-preserving one as long as the precursor conversion is less than 99%. At higher conversions, the particle size distribution reaches the self-preserving limit corresponding to aerosols made by coagulation. A monodisperse model represents well aerosol dynamics at high process temperatures. A design diagram summarizing the significance of surface reaction in terms of φ and d p at various process temperatures is presented.

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