Amino-functionalized hyper-cross-linked resins for levulinic acid adsorption from sugarcane bagasse hydrolysate

BACKGROUND: Levulinic acid (LA) is an important biomass-platform compound. The preparation of LA from biomass will inevitably produce many by-products. However, there are few investigations focused on the separation and purification of LA from biomass hydrolysate. This study designed a series of hyper-cross-linked resins to adsorb LA from sugarcane bagasse hydrolysate, investigated the adsorption behavior of LA onto resin in a fixed-bed system and established a relevant model to depict the adsorption process, which can provide reference for LA separation.RESULTS: The hyper-cross-linked resin G10PTEPA synthesized by poly(styrene-divinylbenzene-glycidyl methacrylate) resin G10 with the Friedel-Crafts reaction and amination reaction using tetraethylenepentamine (TEPA) had the best adsorption performance. The adsorption capacity of LA onto G10PTEPA in the sugarcane bagasse hydrolysate was 95.02 mg g(-1), which was improved by 37% compared with G10. The maximum efficiency of the fixed-bed onto G10PTEPA was 86.01% at flow rate of 0.6 mL min(-1), with bed volume of 14 mL, fixed-bed diameter of 2 cm, and feed LA concentration of 19.0 g center dot L-1. After elution by ethanol, a five-fold increase in the concentration of LA with a purity of 80% was achieved. The Thomas model and the Yoon-Nelson model fitted well (R-2 > 0.99) to the fixed-bed adsorption behavior of LA onto G10PTEPA and can give accurate predictions.CONCLUSION: The resin G10PTEPA was the best-performing adsorbent for LA adsorption. Larger fixed-bed diameter, higher flow rate and higher inflow concentration were beneficial to increase the mass transfer driving force. This study provides a potential adsorbent and theoretical guidance for LA separation.(c) 2023 Society of Chemical Industry.