High yields of HMF from glucose can be achieved using biomass-derived solvents and a combination of solid Lewis and Brønsted catalysts in a salt-free reaction system. The HMF produced in this system can be oxidized to FDCA or hydrogenated to DMF, both being high-value chemicals.
Cellulose was converted with high yield (69%) to levulinic acid (LA) using Amberlyst 70 as the catalyst and using a solution of 90 wt% gamma-valerolactone (GVL) and 10 wt% water as the solvent, compared to the low yield of 20% obtained in water. The LA was upgraded to GVL without any neutralization or purification steps due to the solubilization of humins by the GVL solvent. High LA yields (54%) were also obtained from real biomass (corn stover).