Estimation of fixed-bed column parameters and mathematical modeling of breakthrough behaviors for adsorption of levulinic acid from aqueous solution using SY-01 resin

Levulinic acid (LA) adsorption on a rnicroporous hyper-cross-linked adsorption resin, SY-01, from aqueous solution was performed in a fixed-bed column. Batch equilibrium isotherm was analyzed using Langmuir and Freundlich isotherm models, and the Langmuir isotherm model was found to fit the adsorption isotherm data well. The effects of feed flow rate (Q(f) = 1.0-5.0 mL/min), initial LA concentration (c(f) = 1.0-10.0 g/L), fixed-bed column length (L-c = 5.65-16.96 cm) and fixed-bed column diameter (D-c= 1.6-5.5 cm) on the adsorption characteristics of LA were investigated systematically. The results show that an increase in fixed-bed column length, fixed-bed column diameter, initial LA concentration and a decrease in feed flow rate improve the adsorption performance. Furthermore, a general rate model (GRM) was developed for predicting adsorption breakthrough curves of LA. The mathematical model results were in good agreement with the experimental data under various operating conditions, which confirmed that the GRM can successfully simulate this process. In addition, the values of Biot number (Bi) at different operating conditions were all more than 10, demonstrating intraparticle diffusion is the rate controlling step for the adsorption of LA on the resin. In conclusion, our results provide an important basis for future scale-up of the product recovery of LA from biomass hydrolysate. (C) 2016 Elsevier B.V. All rights reserved.