Real-time observer modelling of a gas-phase ethylene polymerisation reactor.
Loading...
Date
2000
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
The desire for precise polymer property control, minimum wastage through grade transitions,
and early instrument fault detection, has led to a significant effort in the modelling and control
of ethylene polymerisation world-wide. Control is difficult due to complex inter-relationships
between variables and long response times from gas to solid phase.
The approach in this study involves modelling using the kinetic equations. This forms the
basis of a scheme for real-time kinetic parameter identification and Kalman filtering of the
reactor gas composition. The scheme was constructed off-line and tested on several
industrial polymer grades using historical plant data. The scheme was also converted into a
form for use on the linear low-density polyethylene plant, Poly 2, at POLlFIN Limited.
There proved to be no difficulty in the identification step, but the Kalman filter requires more
tuning for reliable fault detection. The software has been commissioned on-line and results
from the POLlFIN plant match the off-line model exactly.
Description
Thesis (M.Sc.Eng.)-University of Natal, Durban, 2000.
Keywords
Ethylene., Polymerization., Chemical reactors., Kalman filtering., Theses--Chemical engineering.