Simultaneous Optimization Model for Multicomponent Separation

Abstract

This paper describes the general optimization model for the simultaneous synthesis of heat integrated separation sequences and their heat exchanger networks (HEN). The model enables an optimal selection of the separation sequence, type of separation units, heat matches, operating conditions and design parameters. The synthesis of the separation sequence can be either homogeneous (the same type of separators) or heterogeneous (different types of separators) allowing sharp and/or nonsharp separations. The synthesis can be carried out either for a separation problem only or for a separation system together with its flowsheet. The model is formulated as a mixed-integer nonlinear problem (MINLP). The approach is illustrated by two examples: one of them presents the homogeneous synthesis of a sharp distillation sequence using a network separation superstructure and a more compact superstructure. The second example presents the application of the general optimization model in the synthesis of the heterogeneous separation system together with its flowsheet when the compact separation superstructure is used.