Dynamic modeling: The influence of the improved solid elutriation correlation on the two‐phase mathematical model of polyolefin polymerization in a gas‐phase fluidized bed reactor

摘要

Abstract Dynamic modeling of the polyolefin polymerization process in the gas phase is relatively complex due to its high nonlinearity. This nonlinearity is induced by several factors including the reaction mechanism, the heat and mass transfer mechanism, the flow properties in both solid and gas phases, the type of reactor, and the correlations between the operating conditions and the chemical and physical properties of the polyolefin. In this study, polymerization of the polypropylene was observed in a fluidized bed reactor to potentially improve the solid elutriation correlations proposed previously, to increase the reliability and the accuracy of this two‐phase model. By embedding the improved solid elutriation correlations, the production rate was reduced relative to earlier proposed solid elutriation correlations due to the loss of the product at the top of the fluidized bed reactor. The composition of the reactants and the catalyst flow rate also influenced the production rate, yet the inlet temperature did not. The current two‐phase model is validated with the pilot plant data with the deviations lower than the previously validated model with reference to the production rate, the concentration of propylene and hydrogen, and the temperature of the reactor.