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Background The production of polymers constitutes the major mass flow in the chemical industry. The foreseeable future change from fossil to renewable resources leads to the demand for more production routes based on biotechnological conversions. These routes preferably require biocompatible components and possess certain limitations of temperature and pH value for the corresponding downstream processing, which can be met by liquid–liquid extraction. This study investigates the extraction of the monomers hexane‐1,6‐diamine and butane‐1,4‐diamine from fermentation media using bis(2‐ethylhexyl) hydrogen phosphate and isostearic acid as reactive extractants and kerosene as well as oleyl alcohol as diluents. Results As expected, the degree of extraction strongly depends on the pH‐value but only weakly on the diluents. A higher diluent polarity leads to a slightly higher degree of extraction at a given pH value. The fraction of reactive extractant can be used to adjust the minimal pH value to reach the desired degree of extraction. No significant influence of fermentation medium, buffer, presence of an E. coli microorganism, or temperature was detected. Conclusion Reactive extraction of bio‐based diamines with organic acids is feasible. The degree of extraction can be adjusted by the fraction of reactive extractant. © 2016 Society of Chemical Industry

Fast and efficient procedures are increasingly important in process development since the time frame between development and market entry is reduced. The evaluation of alternatives is time consuming, but especially important to assure the choice of the optimal process. A simple and fast method to speed up process development while considering numerous alternatives has been developed using option trees. The option trees allow for easy and comprehensible evaluation of alternatives. Here the method of cascaded option trees is illustrated for the development of a biocompatible separation process.

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Extraction is a downstream process option in biobased processes. Because knowledge of phase‐separation behavior is essential for designing efficient separation processes, this study investigates the settling and coalescence behavior of biobased extraction systems by using a standard laboratory‐scale settling cell. The influence of different buffer media and Escherichia coli cells on coalescence was determined for the reactive extraction of hexane‐1,6‐diamine with isostearic acid and di(2‐ethylhexyl)phosphoric acid by using kerosene and oleyl alcohol as diluents. As a result, an increasing pH value of the buffer significantly increases the settling time. The presence of E. coli cells hinders phase separation of the investigated systems, in particular, with dispersed organic phases.