Aconitic acid recovery from sugar-cane stillage: From the modeling of the anion-exchange step to the conception of a novel combined process

Abstract

Sugarcane stillage is rich in tri-carboxylic aconitic acid. To study its purification through anionexchange, selectivity coefficients between aconitate and the major competing minerals were determined on a weak-base resin for different pH. Simulation of solutes separation in column, using mass conservation equations and equilibrium theory, confirmed that resin in sulfate form and pH = 4.5 led to the best separation performances, and showed that a preliminary chloride removal up to 0.5 g L -1 was the most profitable to increase the ionic exchange capacity for aconitic acid. Demineralization of a real stillage by conventional electrodialysis followed by the optimized ion-exchange step, led to an aconitic acid-rich extract.

Aconitic Acid Recovery from Renewable Feedstock and Review of Chemical and Biological Applications

“…Ultimately, the use of the non-ionic Dowex Optipore SD-2 adsorbent was recommended at pH 2.8 and TAA recovery from the adsorbent with butanol at elevated temperatures. A weak anionic resin (sulfate form) was used to remove TAA from a sugar cane-based ethanol distillery by others, where it was noted that while the aconitate can be removed at stillage pH 4.5, a significant amount of inorganic anions and other materials were also removed leading to only 39% purity in the purified extract [ 117 ]. The elution from the anionic resin column was done with weak sulfuric acid.…”