Batch plants with adaptive operating policies

The objective of this paper is to develop an approach for the design of batch chemical processes, accounting for adaptive operating policies to cope with varying parameters. The approach is novel in the sense that it traces variations in process parameters, while previous approaches considered variations in size factors or cycle times. A process model explicit on parameters and control variables is used. The approach proposes to partition the operation of the plant in ''periods'' for which it is possible to assign a set of values for the operating variables in order to adapt to each period occurrence of the varying parameters. Thus, the solution approach is the optimization of a multiperiod formulation. An analysis of the nature of perturbations was made, which led to the proposal of different operating policies, depending on the variations' predictability, time scale and occurrence pattern. A fermentation downstream process is solved as a case study to illustrate the approach, considering variations of a single parameter. Afterwards, we discuss the limitations of the approach and the direction of future work. Considering adaptive operating policies at the design step leads to plants less oversized and with lower operating costs. (C) 1996 Elsevier Science Ltd