DFG Research Collaboration
"Optimization Based Control of Chemical Processes"

The collaborative research project includes four German research groups in the areas of control and process engineering and numerical mathematics. It focuses on development of new methods for optimization based control, or nonlinear model predictive control (NMPC), of chemical processes.

The basic idea of this approach is a prediction and optimization of future process behaviour (using a mathematical model), and the implementation of the optimized process inputs at the real plant for a short time. Then, a new optimization is performed based on new measurements. Among the advantages of this approach to process control are the flexibility provided in formulating the objective and the process model, the capability to directly handle equality and inequality constraints, and the possibility to deal efficiently with nonlinearities during plant start-up, transients, or during batch operation. It is in addition the availability of detailed nonlinear process models -- that are increasingly being used for the design of industrial processes -- which promises to make NMPC an appealing alternative to conventional control.

Though considerable theoretical and practical progress has been achieved in the last years, several problems need still to be addressed: among these are the efficient numerical solution of the resulting optimization problems for large scale systems, online estimation of system state and parameters, and treatment of uncertainties.

In the framework of the collaborative research project based on four combined DFG-research proposals, these open problems are adressed with the aim to result in practicable solutions in particular for process engineering applications. Theory and method development will be driven by two application problems, a chromatographic separation process and a waste water treatment plant.

The combined DFG-project started at July 1, 2003.