Influence of Hydrodynamic Models on Dynamic Response of the Fluidized Bed Polyethylene Reactor

Abstract

In this study, the influence of hydrodynamic models on dynamics of the fluidized bed polyethylene production process has been investigated via modeling. The overall fluidized bed model consists of two integrated sub-models. The hydrodynamic sub-models, which are the simple and dynamic two-phase, well mixed and tanks in series models, were used in the study along with the reaction sub-model from the literature. The hydrodynamic sub-models differ from each other in terms of flow structure and the presence of solids in the disperse phase. The conventional PID controllers were used to control the reactor conditions for these different hydrodynamic conditions. The results of this study showed that a choice of a hydrodynamic model for the fluidized bed polyethylene reactor has a minor effect on the dynamic response and the grade transition of the polyethylene production process and a simple hydrodynamic sub-model can be used for the proper dynamic modeling and control of the process.