Supply-based superstructure synthesis of heat and mass exchange networks

A new simultaneous mixed integer non-linear programing (MINLP) approach to heat exchange network synthesis (HENS) and mass exchange network synthesis (MENS) is presented. This supply-based superstructure (SBS) approach uses the supply temperatures/compositions of all the streams (including utilities) present in the synthesis problem to define heat/mass exchange superstructure intervals. The intermediate temperatures/compositions are variables used in the optimization of the network total annual cost (TAC). The ability of each stream to exchange heat/mass in any interval in the SBS is subject to thermodynamic/mass transfer feasibility. The paper presents the mathematical formulations for optimizing the TAC for HENS and MENS. The SBS synthesis technique has been applied to nine literature problems involving both HENS and MENS. The solutions obtained are in the same range as those in the literature, with one solution being the lowest of all.