Simultaneous Cyclic Scheduling and Control of Tubular Reactors: Single Production Lines

In this work, we propose a simultaneous scheduling and control optimization formulation to address both optimal steady-state production and dynamic product transitions in continuous multiproduct tubular reactors. The simultaneous scheduling and control problem for continuous multiproduct tubular reactors is cast as a Mixed-Integer Dynamic Optimization (MIDO) problem. The dynamic behavior of the tubular reactor is represented by a set of nonlinear partial differential equations that are merged with the set of algebraic equations representing the optimal schedule production model. By using the method of lines, the process dynamic behavior is approximated by a set of nonlinear ordinary differential equations. Moreover, time discretization of the underlying system allows us to transform the problem into a Mixed-Integer Nonlinear Programming (MINLP) problem. Three multiproduct continuous tubular reactors are used as examples for testing the simultaneous scheduling and control optimization formulation.