Available online at www.sciencedirect.com Chemical Engineering and Processing 47 (2008) 745–754 Review Process intensification with reactive extraction columns H.-J. Bart a,∗ , C. Drumm a , M.M. Attarakih b a TU Kaiserslautern, Germany b Al-Balqa Applied University, Amman, Jordan Received 26 July 2007; received in revised form 23 August 2007; accepted 4 November 2007 Available online 17 November 2007 Abstract Process intensification of liquid–liquid extraction columns using reactive extraction systems and population balance modelling approaches are discussed. As a means of process intensification, bulk organic solvents could be replaced by chemically reactive organic phases in order to enhance the extraction efficiency and selectivity. Moreover, extraction of speciality materials could be achieved by using either ionic liquids or solvent phases containing a controlled quantity of surfactants. For deep insight and hence better performance of liquid–liquid extraction columns, population balance modelling approaches can be utilized for process intensification, since the model parameter estimation is possible in small lab-scale devices instead of pilot plant experiments as it is state of the art. A significantly reduced time-to-market period and savings in costs will result. A further improvement can be achieved when the population balance model is coupled to computational fluid dynamics (CFD) where detailed flow fields and turbulent energy dissipation could be obtained. This will foster high-precision engineering, especially with large-scale industrial units. © 2007 Elsevier B.V. All rights reserved. Keywords: Process intensification; Population balance modelling; Computational fluid dynamics; Liquid–liquid extraction; Reactive extraction Contents 1. Introduction ............................................................................................................ 745 2. Selective ligands ........................................................................................................ 746 3. Equilibria and mass transfer in reactive extraction .......................................................................... 748 4. Extraction equipment .................................................................................................... 749 5. Conclusions ............................................................................................................ 753 Acknowledgement ...................................................................................................... 753 References ............................................................................................................. 753 1. Introduction Liquid–liquid extraction, also known as solvent extraction and partitioning, is a method to separate compounds based on their solubility in two different immiscible liquids usually water and an organic solvent [1]. The degree of extraction may be ∗ Corresponding author at: Lehrstuhl f¨ ur Thermische Verfahrenstechnik,TU Kaiserslautern, Postfach 3049, 67653 Kaiserslautern, Germany. E-mail address: bart@mv.uni-kl.de (H.-J. Bart). URL: http://www.uni-kl.de/LS-Bart/ (H.-J. Bart). enhanced by use of multiple contacts where theory and pro- cess layout represented by equilateral–triangular coordinates (with solvent 1, solvent 2 and solute) are given in any process engineering textbooks [2,3]. With respect to process intensifi- cation the bulk organic solvent may be replaced by chemically reactive organic phases, liquid organic salts, surfactant systems, and supercritical fluids in order to serve specific applications [4,5]. Liquefied CO 2 is a common solvent in food industry hav- ing the advantage to obtain a solvent free product after pressure relieve and degassing. The first industrial application was the 0255-2701/$ – see front matter © 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.cep.2007.11.005