(802a) Aqueous Surfactant Two-Phase Systems for the Batch and Continuous Extraction Processes: Experimental Study and Modeling of the Solute Partitioning

Authors: 
Smirnova, I., Hamburg University of Technology



In this work applications of the surfactant-based aqueous two phase systems for batch and continuous extraction processes are discussed.  Special attention is given to the use of such systems for in situ product removal in biotechnological processes.

Based on the state of the art in the literature and the own work it is demonstrated that surfactant/water systems represent a suitable alternative to conventional solvents and can effectively be processed in batch processes and in continuous extraction columns. For this purpose, mainly aqueous nonionic surfactant solutions, which split into two phases if the temperature is increased, are applied. Presently many different types of nonionic surfactants are produced commercially, out of these numerous have been considered as potential solvent for the cloud point extraction.  In this work the crucial thermophysical properties of nonionic surfactants are investigated to determine the potential of surfactant systems for extraction processes. One of the most important parameters for these applications is the partition coefficient, which quantifies the distribution of a specific solute within an aqueous micellar system. Besides this, information about the location of a solute in the system and possible energy barriers have to be retrieved either from experiments or from simulations. Since the experimental effort for these properties is known to be rather high, predictions based on thermodynamic models are favourable. In this work the suitability of the models COSMO-RS and COSMOmic for this purpose is discussed. Both models are applied for the prediction of the partition equilibria in a number of the systems with pure and mixed surfactants. Influences of the additives, pH and temperature on the partition equilibiria are presented. The results of the predictions are compared with own experimental data, obtained by the Micellar Liquid Chromatography (MLC) and Micellar Enhanced Unltrafiltration (MEUF).

Further, the implementation of different surfactant systems in continuous extraction processes is presented based on the own work with a stirred extraction column. The influence of different process parameter and surfactant types and ratios on the separation efficiency is shown.

Finally, potential of different thermodynamic models to describe the liquid-liquid equlibria and solute partition in surfactant-based aqueous solution is discussed.

In this work applications of the surfactant-based aqueous two phase systems for batch and continuous extraction processes are discussed.  Special attention is given to the use of such systems for in situ product removal in biotechnological processes.

Based on the state of the art in the literature and the own work it is demonstrated that surfactant/water systems represent a suitable alternative to conventional solvents and can effectively be processed in batch processes and in continuous extraction columns. For this purpose, mainly aqueous nonionic surfactant solutions, which split into two phases if the temperature is increased, are applied. Presently many different types of nonionic surfactants are produced commercially, out of these numerous have been considered as potential solvent for the cloud point extraction.  In this work the crucial thermophysical properties of nonionic surfactants are investigated to determine the potential of surfactant systems for extraction processes. One of the most important parameters for these applications is the partition coefficient, which quantifies the distribution of a specific solute within an aqueous micellar system. Besides this, information about the location of a solute in the system and possible energy barriers have to be retrieved either from experiments or from simulations. Since the experimental effort for these properties is known to be rather high, predictions based on thermodynamic models are favourable. In this work the suitability of the models COSMO-RS and COSMOmic for this purpose is discussed. Both models are applied for the prediction of the partition equilibria in a number of the systems with pure and mixed surfactants. Influences of the additives, pH and temperature on the partition equilibiria are presented. The results of the predictions are compared with own experimental data, obtained by the Micellar Liquid Chromatography (MLC) and Micellar Enhanced Unltrafiltration (MEUF).

Further, the implementation of different surfactant systems in continuous extraction processes is presented based on the own work with a stirred extraction column. The influence of different process parameter and surfactant types and ratios on the separation efficiency is shown.

Finally, potential of different thermodynamic models to describe the liquid-liquid equlibria and solute partition in surfactant-based aqueous solution is discussed.