A model structure-driven hierarchical decentralized stabilizing control structure for process networks

• A hierarchically structured state-space model form of lumped process systems was developed.
• The exponential stability is proven assuming controlled mass convection network, constant physical properties and stabilizing sources.
• A two level stabilizing controller structure is proposed with the lower level controlling the overall mass.
• The selective stabilizing control layer stabilizes intensive variables with non-stabilizing source terms.
• A simple jacketed CSTR illustrates the proposed control structure.

Based on the structure of process models a hierarchically structured state-space model has been proposed for process networks with controlled mass convection and constant physico-chemical properties. Using the theory of cascade-connected nonlinear systems and the properties of Metzler and Hurwitz matrices it is shown that process systems with controlled mass convection and without sources or with stabilizing linear source terms are globally asymptotically stable. The hierarchically structured model gives rise to a distributed controller structure that is in agreement with the traditional hierarchical process control system structure where local controllers are used for mass inventory control and coordinating controllers are used for optimizing the system dynamics. The proposed distributed controller is illustrated on a simple non-isotherm jacketed chemical reactor.