Adsorption Equilibrium,\nKinetics, and Column Breakthrough\nData for Aqueous Solutions of Binary-Acid and Ternary-Acid Mixtures\nof Acetic Acid, Butyric Acid, and Lactic Acid on IRN-78 Ion-Exchange\nResin at Initial pH Levels of ∼3–7 and at 25–55\n°C

This\nwork is part of an effort to develop thermophysical\nproperty\ndata and models supporting adsorptive process development for organic\nacid separation from a dilute aqueous solution of fermentation broth.\nIt presents systematic experimental measurements for aqueous-phase\nadsorption equilibrium, kinetics, and column breakthrough for three\nbinary-acid aqueous mixtures (acetic acid + lactic acid, butyric acid\n+ lactic acid, and acetic acid + butyric acid) and one ternary-acid\naqueous mixture (acetic acid + butyric acid + lactic acid) on Amberlite\nIRN-78 ion-exchange resin. The equilibrium measurements covered broad\nranges of the initial acid concentration (100–400 mmol/L),\ninitial pH (∼3–7), and temperature (25–55 °C).\nThe equilibrium data for the binary-acid and ternary-acid aqueous\nmixtures indicate selective adsorption of lactic acid at initial pH\nlevels of ∼3 and 4, while acetic acid and butyric acid are\nselectively adsorbed at initial pH levels of 5, 6, and 7. The subsequent\nkinetics and column breakthrough experiments were performed at 200\nmmol/L with equimolar ratios, an initial pH of 6, and 25 °C.\nThe measurements provide essential data sets for rigorous thermodynamic\nmodeling and process simulation of adsorptive separation processes\nfor organic acid separation from fermentation broth.