Comparative Experimental Investigation for the Separation of Tartaric Acid by Natural and Conventional Solvents

Tartaric acid (TA), a valuable organic acid with widespread applications in food, pharmaceutical, and chemical industries, is predominantly found in grapes and winery by-products. This study investigates the physical extraction of TA from aqueous solutions using both conventional solvents (oleyl alcohol, toluene) and natural, non-toxic solvents (rice bran oil, sesame oil). Extraction experiments were conducted at varying acid concentrations (0.04–0.198 mol/L) to determine key separation parameters including distribution coefficient (KD) and extraction efficiency (E%). Among the solvents tested, oleyl alcohol exhibited the highest extraction efficiency (21.72%) and distribution coefficient (0.181), attributed to its amphiphilic nature and low viscosity, which enhance mass transfer and solute interaction. In contrast, sesame oil showed the lowest performance due to its high viscosity and poor polarity. While extraction efficiencies were lower compared to reactive extraction methods, the use of bio-based solvents presents an environmentally sustainable alternative. These results demonstrate the possibility of enhancing acid recovery procedures by using green solvent systems.