Modeling and analysis of a plant for the production of low density polyethylene

Häfele, Martin; Kienle, Achim; Boll, M.; Schmidt, Christian-Ulrich

doi:10.1016/j.compchemeng.2006.05.001

Cited by 16 publications

(28 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It should be pointed out that the dynamic behavior of the whole plant may be completely different from that of the reactor due to the various recycling streams and process units operating at different time-scales [6,7]. In addition, due to the recycling of the unreacted monomers and solvents, impurities are accumulated in the system.…”

Section: The High-pressure Tubular Reactor Technologymentioning

confidence: 99%

“…In addition to the modeling of the tubular reactor, other upstream and downstream unit operations including high-and low-pressure separators, compressors, heat exchangers, etc., need to be simulated to describe the complete dynamic operation of an LDPE plant [6][7][8][9]. The plant-scale model can then be used to conduct process simulation studies, to calculate the optimal operating conditions to maximize plant productivity for a desired polymer grade, or to minimize the off-spec polymer production during a grade transition, etc.…”

Section: The High-pressure Tubular Reactor Technologymentioning

confidence: 99%

See 1 more Smart Citation

From Molecular to Plant‐Scale Modeling of Polymerization Processes: A Digital High‐Pressure Low‐Density Polyethylene Production Paradigm

et al. 2010

View full text Add to dashboard Cite

A generalized multiscale modeling framework is described for the digital simulation of a high-pressure low-density polyethylene (LDPE) tubular reactor. According to the proposed modeling approach, various models describing the complex physical and chemical phenomena at different length and time scales are linked together to assess the effects of reactor operating conditions on the molecular and rheological behavior of LDPE. The molecular properties of LDPE are determined by employing a comprehensive kinetic scheme. On the basis of the postulated kinetic mechanism, detailed population balance equations (PBEs) are derived describing the conservation of the various macromolecular polymer chains. A review of the potential methods for solving the governing PBEs is presented. In addition, a novel kinetic/topology Monte Carlo method to calculate the molecular and topological properties of the highly branched polymer chains and an advanced rheological model for the calculation of the viscoelastic properties of branched polymers in terms of their respective molecular and topological properties are described.

show abstract

Section: The High-pressure Tubular Reactor Technologymentioning

confidence: 99%

Section: The High-pressure Tubular Reactor Technologymentioning

confidence: 99%

From Molecular to Plant‐Scale Modeling of Polymerization Processes: A Digital High‐Pressure Low‐Density Polyethylene Production Paradigm

et al. 2010

View full text Add to dashboard Cite

show abstract

“…9 Although both approaches should yield similar predictions, it has been shown in ref 10 that this is not a trivial issue and that an accurate discretization is required to ensure this in practice. Otherwise, even completely different trends can be observed.…”

Section: Detailed Steady-state Model Of the Industrial Ldpe Reactormentioning

confidence: 94%

Model-Based Optimization of the Cooling System of an Industrial Tubular LDPE Reactor

Vallerio

Logist

Erdeghem

et al. 2013

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

The model-based optimization of the cooling system of an industrial tubular reactor for the production of lowdensity polyethylene (LDPE) is studied in this paper. First a detailed reactor simulator is presented. Second, a series of wellposed optimization problems are formulated and solved. To this end, the optimization problems are presented with an increasing number of degrees of freedom. Moreover, economic cost functions consisting of conversion and energy terms are derived and constraints due to operational and safety reasons are added. The degrees of freedom involve parameters such as the initiator feed rates, the cooling water temperatures, and the switching position between hot and cold cooling water. The optimization results indicate that a dual water circuit operating at a low and a high temperature allows significant improvements in conversion with respect to the reference case of a single temperature circuit, while maintaining similar molecular characteristics.

show abstract

“…Reactor temperature along the reactor varies between 400 and 600 K. Such a reactor is usually very long (>1000 m) and has a small diameter with a large ratio of length to diameter (the order of magnitude Figure 1. Flow diagram of LDPE plant (Reproduced from Häfele et al [9] with permission from Elsevier). Notes: I represents the initiator, I * is the initiator radical, M is the monomer, R is the growing or live polymer radical, P is the dead polymer, n and m denote the degree of polymerization.…”

Section: Process Descriptionmentioning

confidence: 99%

“…A detailed reference dynamic model of the LDPE production plant has been developed in our group [8,9]. The process is represented by a distributed system with an external coordinate (the reactor length) and various internal coordinates (the chain length of the polymer molecules, short-and long-chain branching and the number of double bounds), which can have strong effect on product properties.…”

Section: Reference Modelmentioning

confidence: 99%

Systematic evaluation of models of different complexity for a low-density polyethylene plant

Disli

Kienle

2012

Mathematical and Computer Modelling of Dynamical Systems

View full text Add to dashboard Cite

This study deals with the dynamic modelling and simulation of low-density polyethylene (LDPE) production plant. LDPE is produced in a complex process which takes place under extreme operating conditions and may lead to nonlinear dynamics due to highly exothermic reactions and material recycles around the reactor. In principle, the process is represented by a distributed parameter system with an external coordinate (the reactor length) and various internal coordinates (the chain length of the polymer molecules, short-and long-chain branching and the number of double bounds) resulting in a large scale model. In this contribution a detailed reference model is introduced and possible model simplifications are discussed systematically from on-line optimization and control point of view.

show abstract

Modeling and analysis of a plant for the production of low density polyethylene

Cited by 16 publications

References 12 publications

From Molecular to Plant‐Scale Modeling of Polymerization Processes: A Digital High‐Pressure Low‐Density Polyethylene Production Paradigm

From Molecular to Plant‐Scale Modeling of Polymerization Processes: A Digital High‐Pressure Low‐Density Polyethylene Production Paradigm

Model-Based Optimization of the Cooling System of an Industrial Tubular LDPE Reactor

Systematic evaluation of models of different complexity for a low-density polyethylene plant

Contact Info

Product

Resources

About