Computation of Optimal Feed Rates and Operation Intervals for Tubular Reactors
J. Birk, M. Liepelt, K. Schittkowski, F. Vogel: Journal of Process Control, Vol. 9, 325-336 (1999)
Abstract:
We consider mathematical models for tubular reactors in the form of
dynamic distributed parameter systems. The goal is to maximize the
overall profit over a fixed time horizon, where the number of cleaning
operations, the length of the reactor operation between successive
cleanings, and the reactor feed rates for each time interval are to be
computed. We assume that product prices and consumer demands are
time-dependent. It must be guaranteed that the decrease of the free
cross-sectional area of the tube caused by coke deposition never
exceeds a certain limit. Moreover, there are time and position
dependent constraints for the state and control variables such as a
maximum bound for the temperature. The mathematical model and the
applied discretization scheme are outlined in detail. Numerical results
are presented for a case study, where optimal input feeds and
maintenance times of an acetylene reactor are computed. Of special
interest is the behaviour of the program under real-time conditions,
when changes in the process data or price and user demand functions
require a restart of the calculation.
To download the report, click here:
realtime.pdf
(Acrobat Reader version)