Highly selective recovery of medium chain carboxylates from co-fermented organic wastes using anion exchange with carbon dioxide expanded methanol desorption

• Published in: Bioresource technology Vol. 319; p. 124178
• Main Authors: Fernando-Foncillas, Clara, Cabrera-Rodríguez, Carlos I., Caparrós-Salvador, Francisco, Varrone, Cristiano, Straathof, Adrie J.J.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.01.2021
• Subjects: Anion exchange chromatography; Co-fermentation of organic wastes; CO2-expanded methanol; Hexanoic acid; Medium chain carboxylic acids; Medium chain carboxylic acids; Hexanoic acid; CO2-expanded methanol; Anion exchange chromatography; Co-fermentation of organic wastes
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2020.124178

[Display omitted] •C1-C7 carboxylates were successfully recovered from fermented organic waste.•Strong anion exchange resin preferentially adsorbed hexanoate and heptanoate.•Longer carboxylates were also easier desorbed, allowing their enrichment.•Hexanoate and heptanoate were concentrated up to 0.29 mol/kg and 0.18 mol/kg, respectively. The aim of this work was to recover a mixture of carboxylates ranging from 2 to 7 carbon atoms using a strong anion exchange resin, followed by desorption with CO2-expanded methanol. Medium chain carboxylates hexanoate and heptanoate adsorbed better than acetate, and the corresponding medium chain carboxylic acids desorbed easier than acetic acid. Consequently, hexanoate and heptanoate were concentrated up to 14.6 and 20.7 times, respectively. These findings will enable effective separation and purification of the produced carboxylic acids. Notably, the presence of inorganic ions in the sample, such as chloride, decreased the adsorption affinity compared to a synthetic mixture only of carboxylates.