Recovery of itaconic acid from aqueous solutions usingorganophosphoric extractants by reactive extraction

Itaconic acid is a versatile dicarboxylic acid that can be used in the synthesis of biodegradable polymeric materials. In addition, it is widely used in the synthesis of pharmaceuticals, dyes, resins, biofuels and medical products. The increasing demand and the economic and environmental inadequacies of existing methods necessitated the development of new production and separation methods. In this thesis study, the separation of itaconic acid from aqueous solutions by reactive extraction method was investigated. Trioctylphosphine oxide (TOPO), an organophosphoric extractant, was used in the study. While the concentration of itaconic acid was between 0,05-0,5 mol/L, the concentration of TOPO was between 0,2 and 0,8 mol/L. Toluene, methyl isobutyl ketone (MIBK), octanol and decanol were tested as solvents in the organic phase. In physical extraction experiments, it was observed that itaconic acid could not be transferred to the organic phase with toluene, but was transferred with MIBK, octanol and decanol. At constant extractant concentration, the recovery efficiency increased up to the natural pH value of the solution and then decreased. The highest recovery efficiency was reached at the natural pH value of the solution (pH= 2,14). The system reached equilibrium in 60 minutes. The results obtained at three different temperature points showed the negative effect of temperature increase on separation efficiency. The highest separation efficiencies were 96,08% (KD= 24,50) and 94,12% (KD= 16,00) with toluene and MIBK, respectively. For these two solvents, the recovery efficiency increased with the increase in TOPO concentration while decreased with the increase in acid concentration. Loading factors were less than unity. The results showed that TOPO extractant can be used with a suitable solvent for itaconic acid recovery