Control of an industrial polymerization reactor using flatness

We present our work on the APPRYL PP2 polypropylene plant. We give a physical nonlinear model of the system with a delay on one of the two inputs. This model is flat. Using this flatness property, we show how to design a controller capable of fast and precise transients. Industrial results prove the relevance of our approach. Our controller is in full service since July 1999.

[1]  R. Murray,et al.  Flat Systems , 1997 .

[2]  Sebastian Engell,et al.  A genetic algorithm for online-scheduling of a multiproduct polymer batch plant , 2000 .

[3]  Joachim Rudolph,et al.  Flatness-based control of nonlinear delay systems: A chemical reactor example , 1998 .

[4]  Mark B. Milam,et al.  A new computational approach to real-time trajectory generation for constrained mechanical systems , 2000, Proceedings of the 39th IEEE Conference on Decision and Control (Cat. No.00CH37187).

[5]  J. Macgregor,et al.  Optimal Grade Transitions in a Gas Phase Polyethylene Reactor , 1992 .

[6]  Philippe Martin,et al.  A Lie-Backlund approach to equivalence and flatness of nonlinear systems , 1999, IEEE Trans. Autom. Control..

[7]  Ralf Rothfuß,et al.  Flatness based control of a nonlinear chemical reactor model , 1996, Autom..

[8]  Hugues Mounier.  Proprietes structurelles des systemes lineaires a retards : aspects theoriques et pratiques , 1995 .

[9]  J. Macgregor,et al.  On‐line inference of polymer properties in an industrial polyethylene reactor , 1991 .

[10]  H. Mounier,et al.  First steps towards flatness based control of a class of nonlinear chemical reactors with time delays , 1997, 1997 European Control Conference (ECC).

[11]  S. Godtfredsen,et al.  Ullmann ' s Encyclopedia of Industrial Chemistry , 2017 .

[12]  G. Saridis,et al.  Journal of Optimization Theory and Applications Approximate Solutions to the Time-invariant Hamilton-jacobi-bellman Equation 1 , 1998 .

[13]  Pierre Rouchon,et al.  Minimum time constrained control of acid strength on a sulfuric acid alkylation unit , 2001 .

[14]  N. Faiz,et al.  Optimization of a Class of Nonlinear Dynamic Systems: New Efficient Method without Lagrange Multipliers , 1998 .

[15]  M. Fliess,et al.  Flatness and defect of non-linear systems: introductory theory and examples , 1995 .

[16]  Francis J. Doyle,et al.  Differential flatness based nonlinear predictive control of fed-batch bioreactors , 2001 .

[17]  Michel Fliess,et al.  Systèmes linéaires sur les opérateurs de Mikusinski et commande d'une poutre flexible , 1997 .

[18]  N. Petit,et al.  Systèmes à retards : platitude en génie des procédés et contrôle de certaines équations des ondes , 2000 .