Reactive Extraction of Itaconic Acid Using Quaternary Amine Aliquat 336 in Ethyl Acetate, Toluene, Hexane, and Kerosene

The synthesis method of producing itaconic acid by catalytic condensation of succinic acid and formalin is unsustainable and expensive because it requires huge chemicals, consumes more energy, and discharges harmful chemicals. Production of this acid by fermentation is a relatively clean and less expensive process. The highest cost factor for the acid is the recovery of acid present in dilute form. Reactive extraction is one of the cleaner and more energy-efficient technologies for the recovery of carboxylic acids from dilute streams. Reactive extraction of itaconic acid from aqueous solution using Aliquat 336 (quaternary amine) as the extractant in various diluents was studied. The study highlighted the effects of ester (ethyl acetate), inert (kerosene), aromatic (toluene), and alkane (hexane) on the degree of solvation/ion exchange of the extractants. A comparison among the different categories of diluents was made. The results were presented in the form of distribution coefficient, loading ratio, and equilibrium complexation constant. In most cases, a 1:1 acid−amine complex was observed. Also, attempts were made to relate the distribution coefficient with the various physicochemical properties of the diluent.