Hierarchical Optimal Operation of Continuous-Batch Processes

This paper presents a methodology for the optimal operation of mixed continuous-batch processes based on a hierarchical decomposition of the problem: local dynamic optimizers perform the economic optimization of the batch units or continuous plants, while the upper layer deals with the scheduling of the batch units and the coordination of the flows and properties of sub-processes using a novel simplified model built with predictions from the lower level. The approach is illustrated with a case study from the sugar industry corresponding to the joint operation of the evaporation and crystallization sections operated to maximize production with minimum energy consumption.