Globally Optimal Control of Nonlinear Process Networks: Easier Than Globally Optimal Control of Nonlinear Processes

Optimal control methods for chemical processes abound. The nonlinear behavior of chemical process however limits the success of these methods. Calculus of variations formulations give rise to boundary value problems with possibly multiple solutions. Control parametrization formulations give rise to nonlinear programs which can only be locally solved. In this work, we demonstrate that for large classes of chemical processes the solution of the optimal control problem over both control strategies and process networks is easier (in that it can be solved globally) than the control problem over the control strategy of a single process. We illustrate this surprising discovery by considering an optimal control problem for a particular process network.