Dynamic Modeling and Model Predictive Control for Packed Reactive Distillation Processes

1. Dynamic Modeling and Model Predictive Control for Packed Reactive Distillation Processes Presented by: Sebastien Lextrait Advisor: Dr. Thomas F. Edgar

2. Overview • Introduction • Control Issues • My Research Objectives • Implementation Aspects • Conclusions

3. Introduction • Drawbacks • Complex dynamic behavior • Reduced operability and controllability • Active areas of research • Design methods • Analyses of behavior • Control schemes

4. Control Issues • Objectives • Reactant conversion • Final product purity • Problems • Transition between multiple steady states • Non-minimum phase behavior

5. Control Issues • Control strategy literature • Difficulties with traditional controllers • Purity and reactant conversion • Multiple steady states • Limitations of traditional feedback controllers • Advanced control schemes • Dynamic matrix control method • Output feedback control scheme for some high index DAEs • Nonlinear model predictive control strategy

6. Control Issues • Investigation of MPC control strategy • Performance dependence on model complexity • Problem formulation • On-line implementation not addressed • Computational time • Experimental validation of proposed control schemes

7. My Research Objectives • Four main objectives • Develop dynamic models of different complexity • Model validation and behavior analysis • Investigation of MPC strategy • On-line controller implementation and experimental validation

8. My Research Objectives • Develop dynamic models of different complexity • Equilibrium versus rate-based • Physical properties • Hydraulic model (liquid holdup, vapor holdup, vapor pressure drop) • Catalyst description (diffusion limitations)

9. My Research Objectives • Model validation and behavior analysis • Experimental data • Steady-state • Dynamic • Study the effect of modeling assumptions on the overall model behavior • Computational time • Response accuracy

10. My Research Objectives • Investigation of MPC strategy • Nonlinear programming problem (simultaneous approach) • Investigate state estimation and observer issues for this process • NMPC versus PID and linear MPC • Commercial Software Packages

11. My Research Objectives • On-line controller implementation and experimental validation • Numerical simulations • Real-time optimization issues • Pilot Plant Testing • Interface NOVA to Fisher Rosemount DeltaV distributed control system

12. Implementation Aspects • NOVAoptimization and DAE system • Flexible environment • Optimization and simulation of DAEs • Nonlinear constrained optimization problems • Large-scale problems • Method of weighted residuals on finite elements

13. Implementation Aspects • On-line controller implementation

14. Conclusions • Dynamic modeling of packed reactive distillation required • Investigation of MPC strategy for this non-traditional chemical process • Adapt control scheme for on-line use • Validation with experimental data