A general framework for simultaneous cyclic scheduling and operational optimization of multiproduct continuous plants

Abstract

This paper addresses the problem of integrating in a single model operational optimization and cyclic scheduling of continuous plants. Considered are multiproduct, multistage plants with finite intermediate storage capacity (FIS). A combined optimization approach introduces synergic effects for more effective scheduling and plant operation (Alle and Pinto, 2001a,b). The representation proposed for this problem results in an MINLP model with a nonconvex feasible region and nonconvex objective function. In order to deal with nonconvexity, a spatial branch-and-bound global optimization algorithm is applied. Results show that the global approach is effectively able to yield more profitable solutions than those obtained by local optimization methods.