Selective extraction of glutaric acid from biological production systems using n-butanol

Glutaric acid has numerous industrial applications and it could be used as a polymer building block. Glutaric acid can be produced by chemical or biological methods. Although the biological production of glutaric acid has attracted considerable attention, there are few effective and economical processes for recovering glutaric acid from water based systems. Herein, we investigated the selective extraction of glutaric acid via physical extraction using nine different solvents compared with trioctylamine/toluene as the reactive extraction, which is the only reported method for recovering glutaric acid from biological production systems. Comparisons of the extraction yield, purity, linear solvation energy relationship between the solvents, and reactant selectivity revealed n-butanol to be a suitable solvent for the extraction of glutaric acid, with a high extraction yield and selectivity obtained in less than 30 min under optimized conditions. Furthermore, repetitive extraction allowed 98.4% of glutaric acid to be extracted from the aqueous phase with high solvent recovery and high purity, making this method suitable for practical application.