Disjunctive optimization design models for complex liquid-liquid multistage extractors

• Published in: AIChE journal Vol. 47; no. 10; pp. 2243 - 2252
• Main Authors: Reyes-Labarta, Juan A., Grossmann, Ignacio E.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.10.2001; Wiley Subscription Services; American Institute of Chemical Engineers
• Subjects: Applied sciences; Chemical engineering; Exact sciences and technology; Liquid-liquid extraction; Water; Chloroform; Liquid liquid extraction; Multicomponent mixture; Multistage process; Countercurrent flow; Quaternary system; Optimization; Optimal design; Disjunction; Non linear model; Superstructure; Numerical simulation; Acetic acid; In series; Computer aided design; Acetone
• ISSN: 0001-1541; 1547-5905
• DOI: 10.1002/aic.690471011

A new method for the optimal design of multicomponent liquid–liquid extraction processes using multistage countercurrent extractor systems is proposed. The method determines the optimum number of equilibrium stages and flow rates needed to obtain a specified product separation and recovery, and accounts for the possibility of side feed streams and product extractions. A superstructure is proposed that has embedded all potential configurations and interconnections. Based on this superstructure representation, the problem is formulated as an optimization problem using generalized disjunctive programming (GDP) to minimize the total cost of the process, subject to design specifications. The robustness and computational efficiency of the model is illustrated with different cases involving single and complex countercurrent cascades in a quaternary liquid–liquid system.