Modeling of fluidized bed reactor of ethylene polymerization

A pseudo-homogeneous model is proposed for describing the behavior of fluidized bed reactor for linear low density polyethylene (LLDPE) production. The kinetic model employed in this study is based on the moment equations. The average concentration of particles in the bed is estimated from the dynamic two-phase structure hydrodynamic model. A tanks-in-series model was adopted to describe the flow pattern in the reactor. The hydrodynamic and kinetic models are integrated to the reactor model to make a comprehensive gas-phase LLDPE production reactor model. It has been shown that the results of this model fit the actual data in terms of melt flow index of the produced polyethylene, satisfactorily. The proposed model is capable of predicting the performance of the reactor as well as polymer physico-chemical properties.

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