BATCH PLANTS WITH ADAPTIVE OPERATING POLICIES

The objective of this paper is to develop an approach for the design o f batch chemical processes, accounting for adaptive operating policies to cope with varying parameters. The approach is novel in the sense t hat it traces variations in process parameters, while previous approac hes considered variations in size factors or cycle times. A process mo del explicit on parameters and control variables is used. The approach proposes to partition the operation of the plant in ''periods'' for w hich it is possible to assign a set of values for the operating variab les in order to adapt to each period occurrence of the varying paramet ers. Thus, the solution approach is the optimization of a multiperiod formulation. An analysis of the nature of perturbations was made, whic h led to the proposal of different operating policies, depending on th e variations' predictability, time scale and occurrence pattern. A fer mentation downstream process is solved as a case study to illustrate t he approach, considering variations of a single parameter. Afterwards, we discuss the limitations of the approach and the direction of futur e work. Considering adaptive operating policies at the design step lea ds to plants less oversized and with lower operating costs. (C) 1996 E lsevier Science Ltd