Numerical investigation on preparation of expanded polymer beads using supercritical CO2 in a spouted bed

The bead foaming process in a spouted bed is a green way to manufacture expanded beads. A CFD-DEM model has been established to investigate the hydrodynamics behavior in the spouted bed. The simula-tion results have showed that the establishment of the particle fountain during saturation can effectively disperse the polymer particles and avoid their aggregation. During depressurization, the flow field in the main part of the spouted bed is relatively uniform. Therefore, particles confined within the spouted bed experience similar depressurization profiles, which is beneficial to the uniformity of the expanded beads. Based on the depressurization profiles provided by the CFD-DEM simulation, a bubble evolution model has been built to investigate the effects of operating parameters on the bead foaming results. The simu-lation results indicate that expanded beads with a narrower cell size distribution can be prepared at a higher saturation pressure rather than a higher pressure release rate.(c) 2022 Elsevier Ltd. All rights reserved.