Analysis and Synthesis of Multi-phase Systems using Nonlinear Dynamics

Abstract:
The optimization-based design of chemical processes operated at steady state fails if the resulting design is optimal with respect to an economic cost function, but unstable. While methods for an analysis of the stability boundaries and other types of critical points are established, approaches to automatically considering the dynamics at the design stage do not yet exist. – This work presents a new method for the optimization-based design of steady state processes that takes critical points for process dynamics and operation into account. Based on the notion of the closest distance between a candidate point of operation and any critical manifold in the space of the process and controller model parameters, parametric robustness with respect to stability, more general dynamical features, and feasibility constraints can be considered. The method is successfully tested for various process models. The present work therefore demonstrates that the development of constructive Nonlinear Dynamics methods is possible.