Extractive separation of succinic acid from aqueous solution using non-toxic natural oil and conventional chemical solvents

Succinic acid (SA) is a versatile platform chemical widely utilized across industries such as pharmaceuticals, agriculture, food, and metal processing. It can be produced via the chemical conversion of maleic anhydride or microbial fermentation. However, the recovery of SA from aqueous streams, arising from either process, poses significant challenges due to high costs and usage of toxic chemicals. This study evaluates the feasibility of employing non-toxic, bio-based natural oils (coconut oil and sunflower oil) as alternative solvents alongside conventional solvents (butanol, octanol, decanol, and cyclohexane) for SA extraction. The results are analyzed in terms of distribution coefficient (KD) and extraction efficiency (E%), while also exploring correlations with physicochemical properties such as density, viscosity, dipole moment, and dielectric constant. Among the solvents tested, butanol exhibited superior performance, with a distribution coefficient of 1.227 and an extraction efficiency of 55.1%. The efficiency order for different solvents was determined as: butanol > octanol > decanol > cyclohexane > coconut oil > sunflower oil. The novelty of this study lies in its first-time exploration of coconut and sunflower oils as bio-based solvents for SA extraction, providing an environmentally friendly and sustainable alternative to conventional methods. This work establishes a comparative foundation for the development of greener SA recovery strategies and supports future efforts to optimize bio-based solvent systems for large-scale applications.