CFD simulation of co-precipitation synthesizing nanofibrous γ-alumina precursor in serial membrane dispersion microreactors

Abstract

Herein, a partitioned nucleation and growth model is constructed for the CFD-PBM coupled simulations of pseudo-boehmite (PB), that is, γ-alumina precursor co-precipitation synthesis in the equipment with two serial membrane dispersion microreactors and a circulating continuous phase. The flow condition inside the microreactor is analyzed, and the spiral flow is found to considerably improve the mixing efficiency. Simultaneously, as the phase ratio increases to 54, the average length-diameter ratio of PB nanofibers with an average diameter of 2.3 nm increases to 69, and growth is more dominant than the nucleation. Moreover, the increase of solid content in the continuous phase is dominated by nucleation for the first 10 min, followed by growth and augmentation in the number of nanofibers during 10–60 min, and an increase in the number of nanofibers beyond 60 min. Finally, the simulation results have minor errors by contrast with the experimental data from our previous work.