A comprehensive model for the prediction of particle-size distribution in catalyzed olefin polymerization fluidized-bed reactors

Hatzantonis, H.; Goulas, A.; Kiparissides, Costas

doi:10.1016/s0009-2509(98)00122-5

Cited by 80 publications

(116 citation statements)

References 21 publications

Supporting

Mentioning

111

Contrasting

Order By: Relevance

“…Greek Letters DH r,i heat of reaction of monomer 'i' (J Á mol À1 ) l 0 0 th moment of the total number chain length distribution of 'live' copolymer chains (mol Á m À3 ) l 1 1 st moment of the total number chain length distribution of 'live' copolymer chains (mol Á m À3 ) l 2 2 nd moment of the total number chain length distribution of 'live' copolymer chains (mol Á m À3 ) m viscosity (Pa Á s) x 0 0 th moment of the total number chain length distribution of 'bulk' copolymer chains (mol Á m À3 ) x 1 1 st moment of the total number chain length distribution of 'bulk' copolymer chains (mol Á m À3 ) x 2 2 nd moment of the total number chain length distribution of 'bulk' copolymer chains (mol Á m À3 ) r density (kg Á m À3 ) f instantaneous copolymer composition F cumulative copolymer composition o c polymer mass crystallinity Subscripts and Superscripts 1 ethylene monomer property 2 propylene monomer property b bulk phase property c catalyst property g gas property i monomer number…”

Section: Resultsmentioning

confidence: 99%

“…[17] In order to calculate the individual particle growth rate and temperature profile, one has to solve the monomer and energy balances for each discrete class of particles. According to Hatzantonis et al, [1] the particle growth rate, G D (D), can be expressed in terms of the overall particle polymerization rate, R p , as follows:…”

Section: The Particle Size Distribution Modelmentioning

confidence: 99%

“…During their stay in the bed, the polymer particles grow in size due to polymerization, and can be entrained by the fluidizing gas and/or undergo particle agglomeration, if the reactor operates close to the polymer softening temperature. [1,2] It should be pointed out that, at the particle level, external and internal mass transfer limitations can become significant, especially, in the presence of highly active catalysts. [3,4] This can greatly affect the development of the particle size distribution (PSD) and molecular weight distribution (MWD) in the FBR.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A Multi‐Scale Modeling Approach for the Prediction of Molecular and Morphological Properties in Multi‐Site Catalyst, Olefin Polymerization Reactors

Dompazis

Kanellopoulos

Kiparissides

2005

Macro Materials & Eng

View full text Add to dashboard Cite

Summary: In the present study, a comprehensive, multi‐scale, mathematical model is developed for the calculation of the distributed properties of polymer particles in a gas phase, catalytic, olefin polymerization, fluidized bed reactor (FBR). At the molecular level, a generalized multi‐site, Ziegler‐Natta, kinetic scheme is employed to predict the evolution of the polymer molecular properties. To calculate the particle growth, and the spatial monomer and temperature profiles in a particle, the random pore, polymeric flow model (RPPFM) is utilized. The RPPFM is solved together with a dynamic, discretized, particle population balance model, to predict the particle size distribution (PSD) in the bed. The overall molecular weight distribution (MWD) in the bed is then calculated by the weighted sum of all individual polymer particle MWDs. The effects of hydrogen concentration, the distribution of catalyst active sites, and the polymer crystallinity, on the evolution of the PSD and MWD in an ethylene‐propylene copolymerization FBR are thoroughly analyzed. It is also shown that under certain operating conditions, the proposed multi‐scale model can predict the formation of bimodal MWDs, produced in multi‐stage reactor configurations (e.g., the Borstar® Process, Spheripol, etc.).Schematic representation of the multi‐scale model.magnified imageSchematic representation of the multi‐scale model.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: The Particle Size Distribution Modelmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A Multi‐Scale Modeling Approach for the Prediction of Molecular and Morphological Properties in Multi‐Site Catalyst, Olefin Polymerization Reactors

Dompazis

Kanellopoulos

Kiparissides

2005

Macro Materials & Eng

View full text Add to dashboard Cite

show abstract

“…In the tubular loop reactor, small catalyst particles (e.g. 20-100 m) react with monomers to form polymer particles in a size range of 100-5000 m in a liquid phase and the polymer particles are produced as a solid suspension in the liquid stream [2][3][4][5][6][7][8]. In addition, the polymerization rate, the cost of post-treatment after polymeric process and the polymer properties are influenced by the polymer particle size distribution (PSD) [6][7][8].…”

Section: Introductionmentioning

confidence: 99%

Steady-state particle size distribution modeling of polypropylene produced in tubular loop reactors

Luo

You

et al. 2009

Chemical Engineering Journal

View full text Add to dashboard Cite

“…In this process, small catalyst particles (20-80 mm) react with the incoming fluidizing gas (monomer) to form a broad distribution (100-5000 mm) of polymer particles. 1 In these reactors, the monomer conversion is limited by the rate at which the heat of polymerization can be removed from the reactor.…”

Section: Introductionmentioning

confidence: 99%

Modeling of a fluidized bed propylene polymerization reactor operated in condensed mode

Utikar

Harshe

Mehra

et al. 2008

J of Applied Polymer Sci

View full text Add to dashboard Cite

The gas-phase polymerization of propylene is one of the most widely accepted and commercially used processes for the manufacture of polypropylene (PP). Because of the highly exothermic nature of polymerization reactions, temperature runaway and subsequent polymer melting and agglomeration may occur, and the reactor has to be operated in a small operating window for safety. The addition of liquid monomer for heat removal (condensed mode) broadens the operating window and can substantially increase (by 50-100%) the capacity of given reactor hardware. This article describes the extension of a comprehensive mathematical model for the simulation of fluidized bed PP reactors to include the condensed mode of operations. The model is used to determine the influence of the operating parameters on the polymer properties and particle size distribution. The model is also used to determine the effects of two active sites and the reaction kinetics on macroscopic variables. The developed framework is useful for simulating multimonomer, multisite Ziegler-Natta-type olefin fluidized bed polymerization reactors operated under condensed mode.

show abstract

A comprehensive model for the prediction of particle-size distribution in catalyzed olefin polymerization fluidized-bed reactors

Cited by 80 publications

References 21 publications

A Multi‐Scale Modeling Approach for the Prediction of Molecular and Morphological Properties in Multi‐Site Catalyst, Olefin Polymerization Reactors

A Multi‐Scale Modeling Approach for the Prediction of Molecular and Morphological Properties in Multi‐Site Catalyst, Olefin Polymerization Reactors

Steady-state particle size distribution modeling of polypropylene produced in tubular loop reactors

Modeling of a fluidized bed propylene polymerization reactor operated in condensed mode

Contact Info

Product

Resources

About