Prediction of minimum fluidisation velocity using a CFD-PBM coupled model in an industrial gas phase polymerisation reactor

Abstract

The objective of this paper is to present a new computational fluid dynamic (CFD)- population balance model (PBM) coupled model to predict a minimum fluidization velocity in gas phase fluidized bed reactor (FBR). The generic CFD-PBM coupled model framework hasbeen developed for gas phase polymerization reactor. The population balance model (PBM) bydirect quadrature method of moment (DQMOM) implemented in CFD framework is used to predict minimum fluidization velocity in industrial polydisperse gas phase LLDPE polymerization reactor. The simulation results of pressure drop and bed height were validated bycomparing with the real data from practical plant. The predicted values from the developed CFD-PBM coupled model are in a good agreement with the practical data, with errors of 0.75%and 1.25% for pressure drop and bed height, respectively. Then the minimum fluidizationvelocity is obtained based on the predicted pressure drop and gas velocity. This CFD-PBM coupled model can be further extended to investigate the flow field and particle kinetic throughthe reactor.