Generalized Modular Framework for Distillation Column Synthesis

In this work the distillation column sequencing problem is addressed through the Generalized Modular Framework, based on formal superstructure optimization techniques. The proposed method overcomes structural complexities through the use of systematically composed structural models incorporating all the feasible sequencing alternatives. The generated sequences are evaluated with respect to their cost efficiency, based on aggregated physical models, enhanced with principles of the Orthogonal Collocation technique for distillation order reduction. This allows the generation of compact optimization problems, while avoiding the use of potentially limiting simplifying assumptions. The synthesis method coupled to a formal Mixed Integer Nonlinear Programming (MINLP) solution algorithm, was applied for a number of sequencing case studies generating substantial economic savings by finding systematically and accurately the most cost efficient column sequence.