A MULTIPERIOD MINLP MODEL FOR THE SYNTHESIS OF FLEXIBLE HEAT AND MASS-EXCHANGE NETWORKS

This paper addresses the problem of how to synthesize mass and heat ex change processes, in which stream flowrates and their inlet compositio ns and temperatures may vary according to a set of discrete values. A unified hyperstructure representation of mass and heat exchange altern atives is introduced to account for all mass and heat integration poss ibilities. A multiperiod mixed integer nonlinear programming (MINLP) m odel is then developed, where a total annualized cost is minimized by balancing capital investment cost (of the heat and mass exchange equip ment and their interconnections) to operating cost (of the hot-cold ut ilities, mass separating agents, etc.). As illustrated with the exampl e problems, the proposed model can be effectively employed for the syn thesis of flexible heat exchanger networks (HENs) and mass exchanger n etworks (MENs) separately or, for the synthesis of separation processe s involving both heat and mass transfer.