Particle Behavior in FBRs: A Comparison of the PBM-CFD, Multi-Scale CFD Simulation of Gas-Solid Catalytic Propylene Polymerization

Abstract

A multi‐scale CFD model has been developed to describe the particle behavior in a polyolefin fluidized bed reactor (FBR). The model consists of a CFD model incorporating a single particle model and a population balance model (PBM). The main particle behavior in the FBR can be calculated using the multi‐scale model. The multi‐scale model is tested by comparing simulation results with experimental data. Three cases including CFD coupled with PBM, CFD–PBM coupled with the single particle model without consideration of external diffusion, and multi‐scale CFD model under consideration of external diffusion are developed to further examine the model. The simulations demonstrate that both intraparticle mass and heat transfers, which are ignored by these conventional CFD–PBM models, have significant effects on the particle behavior.

A CFD-PBM model considering ethylene polymerization for the flow behaviors and particle size distribution of polyethylene in a pilot-plant fluidized bed reactor

“…developed a multi-scale CFD-PBM model to study the polymer particle behaviors in a lab scale FBR [24].…”

“…Intensive research has been conducted to explore the particle flow behaviors and PSDs in combining with the flow dynamics in gas-solid FBRs [6,[21][22][23][24][25][26]. The temporal and spatial PSDs present a significant impact on the solid particles flow characteristics.…”

Computational Fluid Dynamics Simulation of Multiscale Mixing in Anionic Polymerization Tubular Reactors

“…Moreover, predicting the mixing behavior in such reactors is one of the challenges. By contrast, for the polymerization system that occurs in such tubular reactors, the complexity of polymerization kinetics results in greater difficulties because various elementary reactions, rapid increase in viscosity, and uniqueness of a polymerization system for heterogeneity and multiscale features are involved 10–12. Furthermore, polymerization is a strongly exothermic reaction.…”

“…More recently, Zhu et al 11, 12 in Luo's group developed a multiscale product model to characterize polypropylene (PP) formation dynamics in a catalytic fluidized bed reactor (FBR). Gas‐solid flow field, morphological and molecular properties of particles, as well as their dynamics can be simultaneously obtained by solving the unique model that couples CFD model, population balance model, and moment equations.…”

Multiscale Modeling of Mixing Behavior in a 3D Atom Transfer Radical Copolymerization Stirred-Tank Reactor

“…In other words, the effect of operating conditions on the microstructure of polymer products remains unclear. More recently, Luo and co‐workers numerically simulated the multiscale properties of polymerization systems in various reactor types. The group first developed a multiscale product model consisting of the CFD model, the population balance model, and moment equations, to characterize polypropylene formation dynamics in a catalytic fluidized bed reactor.…”