Control configuration for chemical process based on fundamental limitations

The control structure selection for an air separation plant is discussed using the robustperformance number (RPN) as a controllability index. The RPN indicates how potentiallydifficult it is for a given system to achieve the desired performance robustly. It reflects boththe attainable performance of a system and its degree of directionality. The predictions madeby RPN are verified by closed loop simulations. The analysis was performed using a linearnominal model, but can be extended to include nonlinearities and uncertainties.

Keywords:

Controllability measures , Air separation plant , Control structure selection (CSS) , Benchmark problem for CSS