Mariët Slagter (PhD)

Sorption and temperature effects on fluidization behavior in gas-phase polymerization reactors

Introduction

Mariët Slagter, Martin van Sint Annaland

One of the most important production method of polyolefins is the gas-phase polymerization process based on fluidized bed reactor technology. Despite their use in industry for many years, detailed knowledge on the complete phenomena prevailing in these reactors is still lacking, especially the interplay of particle properties and the hydrodynamics, mass, and heat transfer.

In polyolefin reactors the sorption of monomers and inert gasses into the particles has a profound influence on the fluidization behavior. Due to the change of particle properties, the macroscopic flow profile are altered, which in turn affects the heat and mass transfer at the particle level. This “two way coupling” is shown in Figure 1.

Objectives

The main objective of this PhD research is to fundamentally understand and quantitatively describe the complex interaction between the hydrodynamics in the fluidized bed and the sorption and transport phenomena in/around polymer particles.

 A combined computational and experimental approach is used in this research; the in-house developed CFD models will be adapted to account for sorption and swelling effects of the particles and their influence on the collision parameters. For the validation of the numerical models a pseudo 2D, dense fluidized bed will used constructed and non-invasive optical measuring techniques like PIV and DIA will be used.

First results

Due to the sorption of monomers and inert gas the collision parameters of the particles change. In Figure 2 computer simulation results demonstrate the important impact of the collision parameters on the bubble properties.

Acknowledgement

This work is part of the research program of the Dutch Polymer Institute (DPI), project: Integrated models for polyolefin reactors (#709). This project is in cooperation with the research group of Prof. McKenna, Lyon, France.

Contact

Ir. H.M. (Mariët) Slagter

h.m.slagter@tue.nl