Dynamic simulation of a PVC suspension reactor

A complete model for the simulation of vinyl chloride batch suspension polymerization reactors, capable of calculating pilot-scale and industrial-scale reactors, is developed. The model solves the mass balances and moment equations, on one hand, and the energy balances for the suspension, reactor wall, and cooling jacket fluid on the other hand. The controller loop, which determines the flow rate or temperature of the cooling liquid, is also included. The kinetic model is based on calculated diffusional contributions and experimentally estimated intrinsic rate coefficients. [T.

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“…Kiparissides et al calculated an increase in the suspension viscosity by 1 order of magnitude. Dimian et al . calculated a factor-of-5 increase.…”

Section: Resultsmentioning

confidence: 99%

“…Mejdell et al focused on the cooling circuits in large-scale reactors, without implementing diffusion-controlled polymerization kinetics. Bretelle and Macchietto and Dimian et al . identified adjustable parameters in the kinetic model of Xie et al to obtain agreement with industrially measured data.…”

Section: Introductionmentioning

confidence: 89%

Simulation of Pilot- and Industrial-Scale Vinyl Chloride Batch Suspension Polymerization Reactors

Wieme

Roo

Marin

et al. 2007

Ind. Eng. Chem. Res.

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“…[1][2][3][4][5][6][7][8] However, due to the complexity of physical and chemical phenomena taking place in the reactor, each publication treats only a special aspect of the process (e.g. reactor kinetics, phase equillibria, particle size distribution, etc.).…”

Section: Introductionmentioning

confidence: 99%

“…In the past 20 years, several mathematical models have been developed to describe the two phase suspension polymerisation of VCM. [1][2][3][4][5][6][7][8] However, due to the complexity of physical and chemical phenomena taking place in the reactor, each publication treats only a special aspect of the process (e.g. reactor kinetics, phase equillibria, particle size distribution, etc.).…”

Section: Introductionmentioning

confidence: 99%

Computer aided design and operation of industrial poly(vinyl chloride) batch suspension polymerisation reactors

Krallis¹,

Kiparissides²

2008

Plastics, Rubber and Composites

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A comprehensive multiscale, multiphase dynamic model is developed to simulate heterogeneous vinyl chloride (VCM) suspension polymerisation in industrial batch reactors. From the numerical solution of the proposed integrated model, the evolution of the molecular (i.e. molecular weight distribution, long chain branching, short chain branching, terminal double bonds) and morphological (i.e. particle size distribution, porosity) polymer properties in a PVC batch suspension polymerisation reactor can be predicted. In particular, the polymer molecular properties are determined by employing a kinetic mechanism which describes the VCM free radical polymerisation in both monomer and polymer rich phases. Semi-empirical and phenomenological expressions are used to describe the breakage and coalescence rates of dispersed monomer droplets in terms of the type and concentration of suspending agent, quality of agitation and evolution of the physical, thermodynamic and transport properties of the polymerisation system. The dynamic discretised particle population balance equation (PBE) is solved to calculate the dynamic evolution of the particle size distribution of the produced PVC. Furthermore, the primary particle size distribution (PPSD) inside the polymerising monomer droplets, which influences to a large degree the porosity of the final PVC grains, is determined by the solution of a PBE governing the nucleation, growth and aggregation of the primary particles. Finally, dynamic mass and energy balances are derived to assess the dynamic behaviour of the PVC batch suspension polymerisation reactors. The theoretical model predictions show good agreement with a comprehensive series of experimental data provided by the PVC industry. This verification of the proposed model makes it a powerful tool for the simulation of large scale PVC batch suspension polymerisation reactors.

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“…In the past 30 years, several mathematical kinetic models have been developed to describe the two-phase suspension polymerization of VCM. ,− All of these studies have been limited to the development of kinetic models for single monofunctional initiators and/or mixtures of them. However, there is growing interest in the polymer industry in the use of multifunctional initiators.…”

Section: Introductionmentioning

confidence: 99%

A Comprehensive Kinetic Model for the Free-Radical Polymerization of Vinyl Chloride in the Presence of Monofunctional and Bifunctional Initiators

Krallis

Kotoulas

Papadopoulos

et al. 2004

Ind. Eng. Chem. Res.

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A comprehensive kinetic model is developed for the suspension free-radical polymerization of vinyl chloride (VC) initiated by a mixture of monofunctional and bifunctional initiators. The model predicts the monomer concentrations in the gas, aqueous, and polymer phases; the overall monomer conversion; the polymerization rate; the polymer chain structural characteristics (e.g., number-and weight-average molecular weights, short chain branching, and number of terminal double bonds); the reactor temperature and pressure; and the coolant flow rate and temperature in the reactor's jacket over the whole batch polymerization cycle. The capabilities of the model are demonstrated by a direct comparison of model predictions with experimental data on monomer conversion, number-and weight-average molecular weights, and reactor pressure. It is shown that high molecular weights and high polymerization rates can be obtained in the presence of a mixture of monofunctional and bifunctional initiators. Moreover, the use of bifunctional initiators results in a significant reduction of the polymerization time without impairing the final molecular weight properties of the polymer. To our knowledge, this is the first comprehensive kinetic modeling study on the combined use of monofunctional and bifunctional initiators on the free-radical suspension polymerization of VC. Taking into consideration the excellent agreement of the model predictions with the experimental measurements, the proposed model should find wide application in the design, optimization, and control of industrial poly(vinyl chloride) batch reactors.

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Dynamic simulation of a PVC suspension reactor

Cited by 8 publications

References 3 publications

Simulation of Pilot- and Industrial-Scale Vinyl Chloride Batch Suspension Polymerization Reactors

Simulation of Pilot- and Industrial-Scale Vinyl Chloride Batch Suspension Polymerization Reactors

Computer aided design and operation of industrial poly(vinyl chloride) batch suspension polymerisation reactors

A Comprehensive Kinetic Model for the Free-Radical Polymerization of Vinyl Chloride in the Presence of Monofunctional and Bifunctional Initiators

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