Synthesis of distillation sequences with several multicomponent feed and product streams

Abstract In this paper the synthesis problem of distillation-based separation sequences that separate a number of multicomponent feed streams into a number of multicomponent products is addressed. A synthesis strategy is proposed that consists of: (a) the development of a distillation-based superstructure that has embedded many separation configurations as well as options for splitting, mixing and by-passing; (b) simulation runs performed for each of the distinct distillation columns involved in the superstructure; and (c) the mathematical formulation of the distillation-based superstructure as a mixed-integer linear programming problem which has as unknowns the stream interconnections. The solution of this mathematical formulation results in the optimal configuration of distillation columns that can perform the desired separation task, as well as in the optimal allocation of by-passes. The synthesis strategy is illustrated with the first two example problems while the third example demonstrates the use of the proposed approach as an initialization procedure for the general separation problem.