Stability analysis of structured chemical engineering systems via decomposition

The stability properties of highly dimensional chemical engineering systems are investigated using a decomposition method and vector Lyapunov functions. Finite stability regions are found for sequences of three and sixteen stirred tank reactors within which a first order exothermic reaction occurs. The stabilty region is of a shape one would expect intuitively on the basis of the sequential structure of the system and of a much larger size than was previously reported in the literature. The computational effort involved is negligible. In addition bounds on the input fluctuations are developed for which the system is stable. These input-output stability criteria can generally not be obtained from a direct application of Lyapunov's theory and appear to be of practical interest.