Aqueous Surfactant Two-Phase Systems for the Continuous Countercurrent Cloud Point Extraction

Aqueous nonionic surfactant solutions split into two phases if the temperature is increased beyond a certain temperature, the so-called cloud point temperature. 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. Phase equilibria of the binary system TritonX-114/water and the ternary system Triton X-114/water/phenol were measured. Based on these data the cloud point extraction was implemented in a continuous stirred extraction column. It was found, that increasing temperature within the column reduces the loss of surfactant and leads to an increasing enrichment factor. This work demonstrates that surfactant/water systems represent a suitable alternative to conventional solvents and can effectively be processed in continuous extraction columns

Continuous Countercurrent Extractive Biocatalysis in Aqueous Surfactant Two-Phase Systems

To evaluate the possibility of performing extractive biocatalysis in continuous mode, the hydrolysis of penicillin G in a micellar solution containing the nonionic surfactant Tergitol NP-7 was chosen as model system. While the product phenylacetic acid distributes into the micellar phase, 6-aminopenicillanic acid moves preferably into the aqueous phase. The yield in the continuous multi-step process was higher in comparison to equivalent batch systems. Overall, the results demonstrate the suitability of aqueous surfactant two-phase systems for continuous biocatalytic reactive extraction processes