HEAT INTEGRATION FOR BATCH PROCESSES - PART 1 - PROCESS SCHEDULING BASED ON CASCADE ANALYSIS

A systematic mathematical formulation is presented in this paper for t he scheduling of some batch processes operated cyclically, involving t he policy of no intermediate systematic mathematical formulation is pr esented in this paper for the scheduling of storage, but with heat int egration. The formulation is based on cascade analysis and leads to an MINLP model. Extensive heat recovery from batch processes including t he case of multiple stream matching can be accommodated by this model. An optimal schedule is found under the condition that heat is recover ed in the mode of countercurrent exchange, but other types of heat exc hange may be introduced after rescheduling. Because of the computing d ifficulties for solving the MINLP model, some problem preprocessing me thods for reducing the size of the model as well as several simplified solving strategies are proposed. These simplified solving strategies require the solution of an MILP model or a series of LP models. The pr oposed problem preprocessing methods and solving strategies are demons trated by examples.