Classical-simple-chemical system for 5'-hydroxymethylfurfural recovery formed during the hydrothermal treatment of saccharide materials

5'-hydroxymethylfurfural (HMF) can be produced from carbohydrate-containing bioresources and wastes, and therefore, its potential as a sustainable alternative in the chemical industry has been extensively investigated. Environment-friendly hydrothermal systems have been explored as efficient methods for converting cellulose-containing materials (such as cotton and wood waste) into HMF. However, recovery and purification techniques for HMF are yet to be fully developed, which hinders the establishment of a commercial-level series of processes for producing HMF. To this end, we developed a hydrothermal flow process for producing HMF from cotton-containing waste using hydrothermal solutions, successfully decreasing the running temperature to 225 °C using citric acid. In this study, we demonstrated a practical purification method to obtain HMF from an HMF-containing product solution. The proposed method uses classical, simple, and well-known materials such as ion-exchange resins, activated carbon, and ethanol. The conditions for the selective removal of BBPs against HMF from hydrothermally treated products using ion-exchange resins were optimized. HMF was purified within 60 min using an anion-exchange resin, the adsorption of HMF using activated carbon was completed within 30 min, and the desorption using ethanol was performed within 10 min. The purity of the obtained HMF was comparable to or better than that of commercially available authentic HMF.