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A pseudo‐transient optimization framework for periodic processes: Pressure swing adsorption and simulated moving bed chromatography
Author(s) -
Tsay Calvin,
Pattison Richard C.,
Baldea Michael
Publication year - 2018
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.15987
Subject(s) - simulated moving bed , discretization , transient (computer programming) , swing , pressure swing adsorption , process (computing) , tearing , computer science , algebraic number , mathematical optimization , adsorption , engineering , mathematics , chemistry , mechanical engineering , mathematical analysis , organic chemistry , operating system
Periodic systems are widely used in separation processes and in reaction engineering. They are designed for and operated at a cyclic steady state (CSS). Identifying and optimizing the CSS has proven to be computationally challenging. A novel framework for equation‐oriented simulation and optimization of cyclic processes is introduced. A two‐step reformulation of the process model is proposed, comprising, (1) a full discretization of the time and spatial domains and (2) recasting the discretized model as a differential‐algebraic equation system, for which theoretical stability guarantees are provided. Additionally, a mathematical, structural connection between the CSS constraints and material recycling is established, which allows us to deal with these conditions via a “tearing” procedure. These developments are integrated in a pseudo‐transient design optimization framework and two extensive case studies are presented: a simulated moving bed chromatography system and a pressure swing adsorption process. © 2017 American Institute of Chemical Engineers AIChE J , 64: 2982–2996, 2018