Parametric optimization of separation of succinic acid in groundnut oil with Tri‑n‑butyl phosphate using response surface methodology with central composite design

Abstract

ABSTRACT Succinic acid (SA) is a platform chemical for producing biofuel and other green chemicals. Fermentative SA production is a cost – effective and eco – friendly method, with quite a few downstream challenges. The recovery method of reactive extraction shows promise but faces toxicity issues with the diluent and extractant, especially concerning microorganisms in the fermentation broth. Hence, a non – toxic diluent and extractant, or less toxic combinations, are needed for efficient acid recovery. Hence, non – toxic diluents, groundnut oil and sesame oil, were evaluated. Based on the superior extraction efficiency (E%) achieved with groundnut oil, the study conducted reactive extraction of SA from the aqueous phase using tri-n-butyl phosphate (TBP) dissolved in groundnut oil. Using response surface methodology with central composite rotatable design, E% was maximized by optimizing independent variables, which were: initial SA concentration– 0.2525 mol L−1, TBP concentration in groundnut oil as the extractant– 50%, shaking time–4 h, pH– 3. These conditions resulted in a distribution coefficient of 0.951 and E% of 48.75%, which are closely aligned with the predicted values of 0.953 and 50.21%, respectively. Fourier Transform Infrared Spectroscopy analysis confirmed a 1:1 complex formation in the organic phase. The results provide insights into the efficient recovery of SA from the fermentation broth.