Construction of an integrated platform for 5-HMF production and separation based on ionic liquid aqueous two-phase system

The research aims to develop a green and sustainable process for the production and extraction of 5-HMF from fructose using an aqueous two-phase system (ATPS) based on ionic liquid (IL). Because there is a large amount of research on the preparation of 5-HMF from fructose, there is no more effective way to separate them. It is very important to develop a method of selective separation, so the IL-based ATPS were studied and evaluated. The phase diagram of the novel IL-ATPS consisting of [C4mim][CF3SO3] and inorganic salts were determined. Different processing parameters, such as the concentration of inorganic salts and ionic liquids, the temperature and time of the separation system were investigated, optimize the process to maximize the separation of 5-HMF from the reaction system. The results showed that the ATPS of K3C6H5O7 and NaH2PO4 salts had the highest extraction efficiencies of 5-HMF and fructose in the two phases, which were 95.73 ± 0.26% and 97.27 ± 0.41%, 97.26 ± 0.10% and 95.51 ± 0.06%, respectively. The system was used to separate a variety of biomass-derived carbohydrates and 5-HMF, and it was found that a good separation effect was obtained, and the constructed system has broad applicability. The created production separation integrated platform is of great significance for getting high purity 5-HMF and fructose recycling.