an official journal of: published by:
an official journal of: published by:
Editor in Chief: RAFFAELLO COSSU


  • Kyra Atessa Vogt - Department of Civil and Environmental Engineering, University of Applied Sciences Darmstadt, Germany
  • Leonie Wenzel - Department of Civil and Environmental Engineering, University of Applied Sciences Darmstadt, Germany
  • Iris Steinberg - Department of Civil and Environmental Engineering, University of Applied Sciences Darmstadt, Germany

Released under CC BY-NC-ND

Copyright: © 2023 CISA Publisher


The production of bio-based platform chemicals through the chain elongation of short-chain carboxylic acids to medium-chain carboxylic acids by ethanol-acetat fermentation can be a contribution to the circular economy. To avoid further waste, secondary waste that already contains short-chain carboxylic acids can be used. The potential for the production of bio-based carboxylic acids from a secondary waste of a recycling plant for plastic waste is examined in this paper. Therefore, practical experiments with the process water of a recycling plant for plastic waste were conducted in order to assess the potential for carboxylic acids production. At the end of the experiment, the concentrations achieved by chain elongation in the secondary waste result in 496 mg/L butyric acid and 87 mg/L caproic acid and the concentration in the extraction solvent is 933 mg/L caproic acid. To conclude, chain elongation of carboxylic acids in secondary waste, in this case the process water from a treatment plant for plastic waste, is generally possible. In order to estimate the total potential for the production, the fluctuations of the quality of the process water have to be considered.


Editorial History

  • Received: 27 Feb 2023
  • Revised: 25 May 2023
  • Accepted: 22 Jun 2023
  • Available online: 30 Jun 2023


Angenent, L. T., Richter, H., Buckel, W., Spirito, C. M., Steinbusch, K. J. J., Plugge, C. M., Strik, D. P. B. T. B., Grootscholten, T. I. M., Buisman, C. J. N., & Hamelers, H. V. M. (2016). Chain Elongation with Reactor Microbiomes: Open-Culture Biotechnology To Produce Biochemicals. Environmental Science & Technology, 50(6), 2796–2810.
DOI 10.1021/acs.est.5b04847

Anneken, D. J., Both, S., Christoph, R., Fieg, G., Steinberner, U., & Westfechtel, A. (Eds.). (2012). Fatty Acids: in Ullmann’s Encyclopedia of Industrial Chemistry. Wiley-VCH Verlag GmbH & Co. KGaA.
DOI 10.1002/14356007.a10_245.pub2

BMBF, & BMEL. (2020). Nationale Bioökonomiestrategie. Berlin. Referat Nachhaltiges Wirtschaften, Bioökonomie (BMBF); Referat Bioökonomie, Stoffliche Biomassenutzung (BMEL)

European Union. (2015). Eurostat - Statistics Explained: Glossary “secondary waste” (ISSN: 2443-8219).

European Union. (2020). Circular economy action plan: For a cleaner and more competitive Europe. Publications Office of the European Union.
DOI 10.2779/05068

Federle, S., Hergesell, S., & Schubert, S. (2017). Die Stoffklassen der organischen Chemie: Praktisch und kompakt von Studenten erklärt (1. Aufl. 2017). Springer Berlin Heidelberg

Groof, V. de, Coma, M., Arnot, T., Leak, D. J., & Lanham, A. B. (2019). Medium Chain Carboxylic Acids from Complex Organic Feedstocks by Mixed Culture Fermentation. Molecules (Basel, Switzerland), 24(3).
DOI 10.3390/molecules24030398

Hemming, W., & Wagner, W. (2017). Verfahrenstechnik (12., korrigierte Auflage). Kamprath-Reihe. Vogel Media Business; GmbH

Hopp, V. (2018). Chemische Kreisläufe in der Natur: Chemie - Biologie - Energetik (2. Aufl. 2018). Springer Berlin Heidelberg

OECD. (2019). Global Material Resources Outlook to 2060: Economic Drivers and Evironmental Consequences. OECD.
DOI 10.1787/9789264307452-en

Sarkar, O., Rova, U., Christakopoulos, P., & Matsakas, L. (2021). Ethanol addition promotes elongation of short-chain fatty acids to medium-chain fatty acids using brewery spent grains as substrate. Journal of Environmental Chemical Engineering, 9(5), 105990.
DOI 10.1016/j.jece.2021.105990

Sarria, S., Kruyer, N. S., & Peralta-Yahya, P. (2017). Microbial synthesis of medium-chain chemicals from renewables. Nature Biotechnology, 35(12), 1158–1166.
DOI 10.1038/nbt.4022

Stegmann, P., Londo, M., & Junginger, M. (2020). The circular bioeconomy: Its elements and role in European bioeconomy clusters. Resources, Conservation & Recycling: X, 6, 100029.
DOI 10.1016/j.rcrx.2019.100029

Wang, J., & Yin, Y. (2022). Biological production of medium-chain carboxylates through chain elongation: An overview. Biotechnology Advances, 55, 107882.
DOI 10.1016/j.biotechadv.2021.107882

Wiese, J., & König, R. (2007). Praxisbericht Laboranlytik und Prozess-Messtechnik: Prozessbegleitende Fermenterüberwachung auf Biogasanlagen (DOC040.72.00447.May07).