Catalytic production of 5-hydroxymethylfurfural from sucrose and molasses by aluminum chloride in green aqueous γ-valerolactone system

5-Hydroxymethylfurfural (HMF) is a promising platform chemical for production of value-added chemicals and fuels. Conversion of abundantly available and cheap sucrose for HMF synthesis was systematically investigated in the present study. Results showed that Lewis acid AlCl 3 is effective in catalytic transformation of sucrose. Combining AlCl 3 with different Brønsted acids, no matter whether they were inorganic acids (HCl, H 2 SO 4 , and H 3 PO 4 ) or organic acids (malic acid, succinic acid, and oxalic acid), or variation of ratio of Lewis acid/Brønsted acid represented by AlCl 3 /HCl, did not change the obtained maximum HMF yields compared with AlCl 3 alone, but shortened the time required to reach the maximum HMF yield. Sucrose conversion in a green reaction media of aqueous γ-valerolactone (GVL) solvent resulted into comparable HMF yields with dimethyl sulfoxide (DSMO)-water system. Addition of monovalent salt NaCl and divalent salt Na 2 SO 4 produced opposite effect with Cl − promoting while SO 4 2− inhibiting HMF production. Furthermore, HMF synthesis from constituent monosaccharides of sucrose and molasses, a by-product from sugar manufacturing process, was also carried out and it was found that an equivmole mixture of glucose and fructose gave rise to almost identical HMF yield to the same mole of sucrose. Molasses, even after chemical pretreatment for removal of certain amount of inorganic salts and color substances, was significantly inferior to synthetic molasses in terms of HMF formation, indicating the complexity and difficulty in chemical valorization of molasses for production of platform molecules.