Dynamic simulation of a tubular reactor for the production of low-density polyethylene using adaptive method of lines

Abstract

The dynamic mathematical model of a tubular reactor for the production of low-density polyethylene (LDPE) is introduced and simulation studies of a LDPE plant are presented. The plant consists of the tubular reactor, compressors, heat exchangers and material recycles. The overall model formulation comprises differential, partial differential and algebraic equations. This model formulation is transformed into a DAE system using an adaptive method of lines approach, where the grid points may change their position but their number remains constant. With this technique a solution on a standard PC is possible. © 2005 Elsevier B.V. All rights reserved. [accessed 2014 January 9th

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

“…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.…”

Dynamic Modeling and Simulation of Low Density Polyethylene Production – A Comparative Study

“…A detailed reference dynamic model of the LDPE production plant has been developed in our group [2,1]. The process is represented by a distributed system with an external coordinate (the reactor length of 2 km) 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.…”

“…The objective of this study is to provide a benchmark model of the LDPE plant with a reasonablemodel size which can be useful for optimal control approaches. Therefore first a detailed reference model developed in our group [2,1] is reviewed and then possible model simplifications are introduced systematically. The reference model of the LDPE plant is represented by a distributed system with an external coordinate (the reactor length > 1000 m) 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.…”

Model based optimisation of tubular reactors for LDPE production

“…Mathematical models have proven to be valuable tools for analysing and optimising the operation, control and design of chemical processes. Also for tubular LDPE reactors models of different complexity have been employed for (i) steady-state simulation [Zabisky and Chan, 1992, Kiparissides, 1996, Brandolin et al, 1996, Bokis et al, 2002 and optimisation [Yoon and Rhee, 1985, Brandolin et al, 1991, Yao et al, 2004 as well as (ii) transient simulation [Häfele et al, 2005[Häfele et al, , 2006 and optimisation [Asteasuain et al, 2001]. All examples prove that model based approaches can lead to significant improvements for the manufacturers.…”