Dynamic behavior of industrial gas phase fluidized bed polyethylene reactors under PI control

Research output: Contribution to journalArticlepeer-review

13 Citations (Scopus)

Abstract

A mathematical model describing the UNIPOL process for the production of polyethylene in the gas phase using a Ziegler-Natta catalyst in a bubbling fluidized bed is used to analyze the major processes determining the behavior and performance of these industrially important units. The investigation shows that both static bifurcation (multiplicity of the steady states) as well as dynamic bifurcation (stable/unstable periodic attractors) behavior cover wide regions of the design and operating parameter domain. A conventional proportional-integral (PI) control policy is suggested to stabilize the behavior of the system. The control philosophy covers both aspects of stabilizing unstable steady states as well as compensating for external disturbances. It is shown that for some controller configurations and set points the controlled process can go through a period doubling sequence leading to chaotic strange attractors. The industrial implications of the phenomena discovered for both the open loop (uncontrolled) as well the closed-loop (controlled) systems are analyzed.

Original languageEnglish
Pages (from-to)133-140
Number of pages8
JournalChemical Engineering and Technology
Volume23
Issue number2
DOIs
Publication statusPublished - 2000
Externally publishedYes

ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)
  • Industrial and Manufacturing Engineering

Fingerprint

Dive into the research topics of 'Dynamic behavior of industrial gas phase fluidized bed polyethylene reactors under PI control'. Together they form a unique fingerprint.

Cite this