Efficient Recovery of Itaconic Acid Using Weak and Strong Anion Exchange Resins from Aqueous Solutions

Itaconic acid (IA) has the potential to be one of the industry's most remarkable raw materials, but it must be recovered with high efficiency and selectivity from complex aqueous-based production media. In this study, three types of weak basic anion exchangers (WBAEs, Amberlite IRA-67, Lewatit MP-62, and Lewatit MP-64) and a strong basic anion exchanger (SBAE, Lewatit M-500) were tested for the separation of IA from aqueous solutions. The process was considerably affected by the operating pH, and the highest efficiencies were obtained at pH 3 and 4 with the WBAEs and SBAE, respectively. Equilibration was achieved in ∼60 min, and the data fitted the pseudo-second-order kinetic model for all resins tested. Decreasing yields with an increase in temperature confirmed the exothermic nature of the process. Isotherm curves demonstrated the consistency of the equilibrium data with Type I. The capacities increased with IA concentrations and decreased with resin doses. Lewatit MP-62 achieved the highest capacity (522.7 mg of IA/g of resin), and its performance was significantly better than those previously reported in the literature. The equilibrium data were in agreement with the Langmuir isotherm model; however, the R2 values attained with the Freundlich and Temkin models were also relatively high, indicating the need for further isotherm analyses.