A path constrained method for integration of process design and control

Integration of process design and control (IPDC) has been the holy grail of process systems engineering since the introduction of heat and mass integration. A proper combination of these separate yet connected tasks carries the promise of achieving superior designs that cannot be realized with conventional procedures. In this work, a bi-level dynamic optimization approach is introduced for achieving IPDC in its true sense. The principal idea proposed here is to utilize an optimal controller (a modified linear quadratic regulator) to practically evaluate the best achievable control performance for each candidate design during process design. The evaluation of complete, closed-loop system dynamics can then be meshed with a superstructure-based process design algorithm, thus enabling considering both cost and controllability in design of a process. The practicality of the introduced approach enables a solution of this complex dynamic optimization problem within reasonable computational requirements, as demonstrated in an evaporator case study.