Numerical simulation of yttrium oxide nanoparticle growth in gas-phase flame synthesis using a Conditional Quadrature Method of Moments (CQMOM)

Gas-phase flame synthesis is a useful method for manufacturing metal oxide fine nanoparticles. In order to investigate the particle growth mechanism in detail, we conducted a numerical analysis of laminar flame and particle growth in gas-phase flame synthesis. The analysis focused on the synthesis of Y2O3 nanoparticles from Y(DPM)3. Particle growth was described using the conditional quadrature method of moment (CQMOM) approach, which can represent the local distribution of particle volume and surface area. In terms of the particle growth process, we considered nucleation, collision-based agglomeration, and sintering. Additionally, to describe them precisely, we applied Gauss-Radau quadrature to the CQMOM. The simulation results showed that there are both spatial and local dispersion of particle size. The simulations also revealed the detailed mechanism of collision that particles undergo, and collisions between large particles and small ones were proved to have a substantial effect to particle growth. Increasing precursor partial pressure increased not only particle concentration, but also flame height and spatial dispersion of the primary particle diameter.