Itaconic
acid (IA) is an unsaturated diacid, a promising compound
that might replace part of the petrochemical-based monomers, such
as acrylic acid, as a building block for polymers. Recent developments
in biotechnology allow the efficient production of IA through fermentation
processes. However, further enhancements are necessary in the downstream
(recovery) of the product. This investigation examined the separation
of IA by adsorption from aqueous solutions, using two types of commercial,
strongly basic ion-exchange resins: Purolite A-500P and PFA-300. To
evaluate the separation process, the following parameters were tested:
pH (from 3.03 to 6.33), temperature (from 10 to 50 °C), and IA
concentration (from 0.41 to 6.50 g·L–1). The
Freundlich and Langmuir isotherms were shown to be good fits to the
experimental data, and the adsorption kinetics for IA was found to
follow a pseudo-second-order (PSO) model. After batch tests, continuous
adsorption experiments were carried out using a fixed bed column,
and a simplified mathematical model was developed and evaluated in
order to determine the adsorption parameters. The experimental data
obtained from the column tests were aligned with those obtained from
the isotherms and batch simulations with PSO. The resin PFA-300 proved
to be more efficient for IA recovery through adsorption, with a maximum
capacity of 0.154 gIA.gresin
–1 when compared to the resin A-500P, with a maximum capacity of 0.097
gIA.gresin
–1. Both resins
have high affinity for the solute, being half-saturated with equilibrium
concentrations below 0.25 g·L–1 of acid.