Separation of Acetic Acid, Formic Acid, Succinic Acid, and Lactic Acid Using Adsorbent Resin

The single-component adsorption equilibria of acetic acid and formic acid on an Amberchrom-CG300C resin were measured using a staircase frontal analysis method over the temperature range from (30 to 50) degrees C at liquid-phase concentrations of up to 10 g.L-1. The resultant adsorption data were correlated with the Langmuir model, and the corresponding model parameters were determined. In addition, the effect of temperature on the Langmuir equilibrium constants was investigated, and the results were utilized to determine the thermodynamic parameters for the adsorption of interest. The results of these investigations indicated that the adsorption of each organic acid onto Arnberchrom CG300C is exothermic and controlled by physical mechanisms. Furthermore, a temperature-modulated adsorption model for each organic acid was developed by incorporating its thermodynamic parameters into the Langmuir model. The resultant temperature-modulated Langmuir model equation was confirmed to be highly accurate in predicting all of the adsorption equilibrium data acquired over the investigated temperature range. The adsorption equilibrium data and the model parameters reported in this study will be of great value in designing a chromatographic process for separating the organic acid mixture resulting from fermentation based on Actinobacillus bacteria.