Scale-up and thermal stability analysis of fluidized bed reactors for ethylene polymerization

Abstract

A set of hydrodynamic similarity laws is applied to the scale-up of ethylene polymerization fluidized bed reactors (FBRs) under the condensed mode operation. The thermal stability of open-loop controlled FBRs is investigated by the homotopy continuation method. And the Hopf bifurcation point is selected as an index of the thermal stability similarity. The simulation results show the similarity in state variables, operation parameters, the space–time yield (STY), and the thermal stability of FBRs with different scales. Furthermore, the thermal stability behaviors and similarity of the closed-loop controlled FBRs with different scales are analyzed. The observed similar trend of Hopf bifurcation curves reveals the similarity in the thermal stability of closed-loop controlled FBRs with different scaling ratios. In general, the results of the thermal stability similarity confirm that the hydrodynamics scaling laws proposed in the work are applicable to the scale-up of FBRs under the condensed mode operation.