Effect of precursor loading on non-spherical TiO₂nanoparticle synthesis in a diffusion flame reactor

A numerical method of combining computational fluid dynamics with the particle kinetics theory is developed to study the effect of precursor loading on non-spherical TiO2nanoparticle synthesis in a diffusion flame reactor. A one-step chemical kinetics approach is employed to model precursor TiCl4oxidation that leads to particle formation. An efficient quadrature method of moments (QMOM) and the combustion model based on the eddy dissipation concept (EDC) together with k - ε{lunate} turbulence model are used to approximate the particle kinetics evolution and the flame fields, respectively. Excellent agreements between the predicted and experimental data, with respect to the flame temperature distribution and particle kinetics, are obtained. For the final product of nanoparticles in the same flame field, the results show that the increasing of precursor loading leads to the larger agglomerated particles with larger size distribution. The primary particle number and size per agglomerate also increases with increasing the precursor loading, while the total specific surface area (SSA) decreases. The variation of inlet precursor loading has a negligible effect on the particle surface fractal dimension if only the variable of precursor loading is considered. As the inlet precursor loading is fixed, the increasing of carrying gas rate leads to the smaller agglomerated particles with increasing of total SSA and width of particle size distribution.