Electrochemical membrane-assisted pH-swing extraction and back-extraction of lactic acid

Marcel Gausmann, Angelo Gössi, Franziska Bertram, Wolfgang Riedl, Boelo Schuur, Andreas Jupke*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

7 Citations (Scopus)
85 Downloads (Pure)


Reactive extraction of carboxylic acids such as lactic acid with tertiary amines is a state-of-the-art process but suffers strongly from reduced extraction efficiency in buffered environments like fermentation broths. In order to increase the efficiency of in-situ product removal, we here propose the combination of a membrane-assisted reactive extraction with an electrochemical pH shift. Prior to extraction in the membrane module, the fermentation broth containing the lactic acid at neutral pH is treated by anodic electrolysis to reduce the pH and thereby improve the extraction yield. Additionally, the cathodic reaction is used to increase the pH of the aqueous stream used for back-extraction of the loaded organic phase. Model solutions were used to develop a mathematical model, capable of calculating the required membrane area for in-situ extractions, considering the effect of the aqueous pH on the extraction performance. Additionally, using electrochemical pH shift, we were able to concentrate lactic acid from 1 wt% in the dilute broth to 7 wt% in the back extract.

Original languageEnglish
Article number120702
JournalSeparation and purification technology
Early online date26 Feb 2022
Publication statusPublished - 15 May 2022


  • Electrochemical separation
  • Lactic acid
  • Membrane contactor
  • pH shift extraction
  • Reactive extraction
  • 22/4 OA procedure


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