(569c) Integrated CFD-PBM Simulation for a Continuous Lactose Crystallization Process

In this study, Computational Fluid Dynamics (CFD) was used to simulate a lactose crystallization process in a baffled draft-tube, mixed-suspension, mixed-product removal (MSMPR) cooling crystallizer. The CFD simulation was a multi-component, multiphase simulation, with the lactose solution (primary) and the crystal (secondary) phase. During crystallization of α-lactose monohydrate, both dissolved lactose (95%) and water (5%) were lost from the solution. The Population Balance Model (PBM) was solved with method of moments using three moments. Then, the moments obtained from the CFD simulations were reconstructed into crystal size distribution (CSD) using mixed gamma and log normal distribution functions. The general patterns of the simulated CSD profiles were similar to those observed experimentally. The simulated velocity profiles were also validated by images obtained from a high speed camera system. Compared to other conventional process modeling tools, CFD-PBM simulation provided additional spatial information of solution variables, and the process variables can be evaluated based on the desired characteristic of the final product.