Multiscale modelling of multizone gas phase propylene (co)polymerization reactors—A comprehensive review

Abstract

Catalysts and polymerization processes have evolved over the years. Such significant developments have allowed producers to broaden the range of polymer microstructure and process productivity, thereby making it possible to offer a wide range of end-use properties at a reasonably low cost. However, these advantages in catalyst performance and reactor operation require that we understand as much as possible about reactor operation in the broadest sense. In addition to the fundamental experimental study of polymer chemistry, this means that one needs to develop complete, robust process models. The present paper provides a rapid overview of recent developments in various gas phase propylene (co)polymerization reactors in use today, concentrating on multizone gas phase polypropylene reactors: i.e.,

Bioglycerol-to-Propylene Routes: From Fundamental Catalysis to Process Design and Marketing

“…Propylene belongs to the group of alkenes with three carbon atoms, two of which are double bonded (C=C–C). The relative weakness of this latter bond explains its easy reactivity through different processes such as (co)- and polymerization, − oxidation, , halogenation, , epoxidation, , alkylation, , oligomerization, and dimerization, , etc. This useful reactivity and properties (Table , ) mean that propylene is one of the main platform molecules for several sectors such as the petrochemical, plastics, textile, and automotive industries.…”

Simulation of Molecular and Particle Properties of Polypropylene Produced in Multizone Circulating Reactors

“…1−3 The preparation of PP is mainly conducted via three commercial routes, namely, bulk, slurry, and gas-phase processes. 2 Among them, the gas-phase polymerization process is extensively used due to its low investment cost, high heatremoval capability, and ability to produce a wide range of product properties. In recent years, gas-phase polymerization technology for PP has evolved from single-zone reactors such as fluidized bed reactors, loop reactors, and stirred bed reactors to advanced multizone circulating reactors (MZCRs).…”

“…Polypropylene (PP) is a very high-tonnage plastic worldwide, which has been used for the production of a wide variety of industrial products, such as packaging material, healthcare and pharmaceuticals, construction material, and electrical applications. − The preparation of PP is mainly conducted via three commercial routes, namely, bulk, slurry, and gas-phase processes . Among them, the gas-phase polymerization process is extensively used due to its low investment cost, high heat-removal capability, and ability to produce a wide range of product properties.…”

Multicomponent solubility in gas‐phase polypropylene processes

“…Therefore, precise values of the solubility of a sorbed monomer/co-monomer(s) in amorphous polymer must be measured as a function of the composition of the gas phase to predict accurate reactive species concentrations at the active sites. 2 Solubility data are clearly important as the active sites of the catalyst are buried under a layer of semicrystalline polymer almost immediately, so the vapor-polymer equilibrium in the system will determine the amount of each species present at the reactive sites. Different experimental methods 3,4 have been used in the past to measure the solubility of gases in polymers, and these can be grouped into three main approaches:…”

“…It is well‐known that the presence of heavier components in a mixture of gases can enhance the solubility of the lighter components in the amorphous polymer. This is often referred to as the so‐called “co‐solvent (or co‐solubility) effect.” On the other hand, the lighter species in the gas composition decrease the solubility of the heavier ones via the “anti‐solvent (or anti‐solubility) effect.” Therefore, precise values of the solubility of a sorbed monomer/co‐monomer(s) in amorphous polymer must be measured as a function of the composition of the gas phase to predict accurate reactive species concentrations at the active sites 2 . Solubility data are clearly important as the active sites of the catalyst are buried under a layer of semicrystalline polymer almost immediately, so the vapor‐polymer equilibrium in the system will determine the amount of each species present at the reactive sites.…”