An Insight into the Temperature Field and Particle Flow Patterns in a Fluidized Bed Reactor for Nonpelletizing Polyethylene Process Using a 3D CFD-PBM Model

Abstract

This work aims at exploring the temperature and polyethylene (PE) particle flow patterns in a pilot-plant fluidized bed reactor via 3D CFD modeling approach. A Eulerian–Eulerian model involving ethylene polymerization kinetics is integrated with population balance model to investigate the issues for both traditional pelletizing PE process (TPPP) and nonpelletizing PE process (NPPP). The results show that the regions with large temperature gradients have been observed in top area. The revealed particle flow patterns in two cases are analyzed using four typical flow patterns (patterns a–d) reported in literature. PE particles are vigorously contacted and mixed along the lateral and vertical planes of the reactor in TPPP (patterns b–d). Solid dispersion is intensely enhanced in the bed vertical direction (pattern d), and the flow patterns show larger circular flow (pattern a) in the radial direction under NPPP due to the larger particle size and gas velocity.

Gas‐Phase Polyethylene Reactors—A Critical Review of Modeling Approaches

“…Results showed that particle growth due to polymerization has a remarkable influence on flow fields and solid distribution in the reactor; moreover, particle breakage led to a reduction of average particle size and to an increased axial expansion of the bed. The same research group [ 146 ] further improved the model by adopting a 3D schematization of the reactor; validation was carried out by comparing pressure drops and bed axial height.…”

Effect of Mixing on the Particle Size Distribution of Paracetamol Continuous Cooling Crystallization Products Using a Computational Fluid Dynamics–Population Balance Equation Simulation

“…Although significant achievements have been made, the CFD–PBE simulation of stirred tank under various conditions using different crystallization technology still needs extensive research. Most of the articles applied the method of moments or its derivatives to solve the PBE; − ,,− though computationally efficient, the real particle size distribution could not be obtained. The PSD curve exhibits a double peak or shows a sharp change, resulting from the deconvolution algorithm.…”