Experimental and numerical study of turbulent mixing in a model of a polymerization reactor

Inglès, Xavier; Pallarès, Jordi; Larre, María Teresa; Méndez, Luis; Grau, F.X.

doi:10.1016/j.jiec.2012.12.025

Cited by 8 publications

(10 citation statements)

References 18 publications

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“…These reactors are able to provide appropriate mixing environment for improving product quality, reducing reaction times and enhancing selectivity (Boodhoo and Harvey, 2013b). It is well-documented that a reactor's mixing characteristics affect conversion of monomer as well as molecular weight distribution (Kolhapure et al, 2005), but thorough understanding of underlying interaction between mixing and polymerization is still the subject of numerous studies (Xu et al, 2017), both experimental (Erdogan et al, 2002) and numerical (Inglès et al, 2013;Xie et al, 2016).…”

Section: Introductionmentioning

confidence: 99%

Free-Radical Polymerization of Styrene: Kinetic Study in a Spinning Disc Reactor (SDR)

2021

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Free-radical polymerization of styrene conducted in a spinning disc reactor (SDR) results in significant increases in conversion in one disc pass, equivalent to a few seconds of residence time, with little change in the number average and weight average molecular weights and polydispersity compared to a SDR feed pre-polymerized in a batch reactor. Results of our experimental studies are presented in this paper and a rationale, based on simulation studies, is offered to explain these observations. It is shown that phenomena such as large increases in conversion that do not impact on molecular weights and molecular weight distribution is a result of a simultaneous increase in both the initiator decomposition rate and the propagation rate. The increases in these rate constants, predicted by our modeling studies, provide the driving forces that characterize a polymerization process in a SDR reactor, with the centrifugal force having different degrees of influence on individual reaction steps. This is attributed to different molecular sizes being involved in each of the polymerization reaction steps. The highest impact is observed on the initiator decomposition rate constant, as this reaction step involves a small molecule. Lesser impact is observed on the propagation rate constant, as this reaction step involves interaction of one small molecule and one large reactive species, whilst no or very small effect is seen in the case of the termination rate constant as large reactive species are involved. Developed constant variance model was used to estimate reaction parameters at different temperatures (i.e., initiator efficiency f, rate constants kd, kp, and kt) from the acquired experimental data in order to estimate activation energy (Ea) and pre-exponential factor (A) in a SDR. Data analysis at various SDR operating temperatures suggested activation energy for the styrene polymerization in the SDR as 40.59 ± 1.11 kJ mol−1.

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Section: Introductionmentioning

confidence: 99%

Free-Radical Polymerization of Styrene: Kinetic Study in a Spinning Disc Reactor (SDR)

2021

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“…For such polymerization systems, mixing shows multiscale behaviors, i.e., macroscopic‐scale and microscopic‐scale 14–16. On the one hand, macroscopic‐scale mixing can be described via reactor operation parameter distributions such as temperature, monomer concentration, and polymer concentration.…”

Section: Introductionmentioning

confidence: 99%

“…On the one hand, macroscopic‐scale mixing can be described via reactor operation parameter distributions such as temperature, monomer concentration, and polymer concentration. On the other hand, microscopic‐scale mixing can be investigated using polymer microscopic property profiles such as number‐average molecular weight ( M n ) and dispersity index (PDI) 9, 14, 15. Polymer molecular properties can be greatly influenced by polymerization operation parameters.…”

Section: Introductionmentioning

confidence: 99%

“…Polymer molecular properties can be greatly influenced by polymerization operation parameters. Improper macroscopic mixing leads to uneven operation parameter distributions, which changes polymerization rate profiles in reactors and subsequently causes polymer microscopic property distributions 14–16. Therefore, two scales of mixings are closely related via polymerization rate bridges.…”

Section: Introductionmentioning

confidence: 99%

“…However, in their work, the selected reactor is a CSTR rather than a tubular reactor, and multiscale mixing was not involved. Inglès et al 15 studied turbulent mixing in a polymerization reactor model experimentally and numerically. The model corresponds to a zone of an autoclave reactor installed with a stirrer.…”

Section: Introductionmentioning

confidence: 99%

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Computational Fluid Dynamics Simulation of Multiscale Mixing in Anionic Polymerization Tubular Reactors

2016

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The molecular properties of polymers are greatly influenced by operation parameters during polymerization in reactors. Since operation parameter distributions in reactors also result in molecular property distributions, polymerization bridges the gap between molecular properties and operation parameters. The combination of the computational fluid dynamics technology with the method of moments to form a uniquely coupled model was used to describe multiscale mixing fields in the reactor. The coupled model was validated by open experimental data, and the effects of polymerization kinetics on macroscopic and microscopic fields were investigated numerically. Also, the coupled model was applied to numerically predict the impacts of some key operation conditions on the main macroscopic flow field parameters and polymer molecular properties.

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Mixing in High‐Pressure Polymerization Reactors: A Combined Experimental and Modeling Approach

Ständecke

Gockel

Busch

2023

Chemie Ingenieur Technik

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Mixing in low-density polyethylene (LDPE) reactors is crucial regarding process safety as well as process efficiency. The extreme process conditions of pressures up to 3000 bar make it difficult to get an insight into LDPE reactors. This problem is tackled by a combined experimental and modeling approach. A poly(methylmethacrylate) duplicate of a laboratory high-pressure reactor is set up to measure residence times and visualize flow lines. Experimental results are then compared to a computational fluid dynamics model.

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Experimental and numerical study of turbulent mixing in a model of a polymerization reactor

Cited by 8 publications

References 18 publications

Free-Radical Polymerization of Styrene: Kinetic Study in a Spinning Disc Reactor (SDR)

Free-Radical Polymerization of Styrene: Kinetic Study in a Spinning Disc Reactor (SDR)

Computational Fluid Dynamics Simulation of Multiscale Mixing in Anionic Polymerization Tubular Reactors

Mixing in High‐Pressure Polymerization Reactors: A Combined Experimental and Modeling Approach

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