| A multiple-objective formulation of the synthesis of distillation sequences is presented in this work. The incommensurable criteria, namely economic cost, thermodynamic efficiency, and flexibility index are used to evaluate the alternative sequences. Algorithms for the evaluation of flexibility index of distillation systems have been proposed. The conflicting results among different criteria lead to the development of multiple objective decision-making (MODM) techniques. Compromise programming, implemented with the utility function trade-off (UFT) method, is proposed to select the best compromise solutions.; The validity of commonly used heuristics is challenged by the extensive studies of distillation systems. New heuristics based on thermodynamics have been developed. The concept of most-important solution set (MISS) has been proposed to generate the most attractive candidate sequences. |
