Dynamic modeling and Molecular Weight Distribution of ethylene copolymerization in an industrial gas-phase Fluidized-Bed Reactor

Abstract

A dynamic model for ethylene copolymerization in an industrial fluidized-bed reactor (FBR) is developed to describe its behavior and calculate the properties of polyethylene. The presented model considers particle entrainment and polymerization reaction in two phases. Two-site kinetic and hydrodynamic models in combination, provide a comprehensive model for the gas phase fluidized-bed polyethylene production reactor. The governing moment and hydrodynamic differential equations were solved simultaneously and the results compared with a similar work, as well as industrial data. The dynamic model showed accurate results for predicting Polydispersity Index (PDI), Molecular Weight Distribution (MWD), reactor temperature and polymer production rate.

Computational fluid dynamics simulation of gas–liquid–solid polyethylene fluidized bed reactors incorporating with a dynamic polymerization kinetic model

“…The mechanisms of polymerization kinetics on a Ziegler-Natta catalyst involve a series of elementary reactions and are extremely complicated, which therefore are always described as a simple kinetics model in most works. [5][6][7][8][9][17][18][19]27,28,[33][34][35] As a result, the polymerization FBRs lose much microscale information about polyethylene products properties such as reactant composition changes, molecular weight, and production rate. In this work, a comprehensive polymerization kinetics proposed by McAuley et al 29 is used.…”

Investigation into the Suppression Effects of Inert Powders on the Minimum Ignition Temperature and the Minimum Ignition Energy of Polyethylene Dust

“…However, in order to compare the MIE of the different combustible powders more clearly, only a single value could be used. In the EN 13821 standard, this value can be estimated using the probability of ignition, as stated below: (1) where E2 is the energy level at which ignition occurs and E1 is the energy level below E2 with no ignition after 10 consecutive attempts. I[E2] represents the number of tests with ignition at E2 and (NI + I) [E2] represents the total number of tests at E2.…”

“…During the process of producing PE particles, high concentrations of dust clouds can be formed in the process of granulation, drying, pneumatic transportation, and unloading. This dust can be easily ignited by ignition sources such as static electricity or hot mechanical surfaces [1]. This causes dust explosion accidents and serious casualties and property loss.…”

Advances in Mathematical Modeling of Gas-Phase Olefin Polymerization

“…Solid elutriation is considered [49] Two-Phase Model/Polypropylene Immediate consumption of the propylene after injection the catalyst 3.…”

“…[ [48][49][50][51][55][56][57][58][59]62,95,96,102] As mentioned in Table 3, the number of stages in the reaction mechanism for this olefin polymerization process in the gas phase via the coordination mechanism by using the organometallic catalyst, namely Ziegler-Natta catalyst, metallocene-based catalyst, or chromium oxide-based catalyst implemented previously differ from one study to another study. Most of the studies considered that the polymerization reaction commences by activating the active site.…”