Role of solvent in enhancing the production of butyl levulinate from fructose

The use of alkyl levulinates is growing interest in fuels. Adding n-butyl levulinate (BL) to fuels presents some benefits compared to ethyl levulinate. The conventional production route of BL is from the esterification of levulinic acid, but the latter compound presents some corrosion issues. Alcoholysis of fructose by butanol over cation exchange resins (solid catalyst) seems to be a better alternative. The effect of water addition, solvent, swelling effect (from the cation exchange resin), and fructose solubility at temperatures higher than 25 °C are unclear on this reaction. To understand these effects, the alcoholysis of fructose by butanol at 110 °C in different solvents, e.g., gamma-valerolactone (GVL), were studied in a pressurized autoclave in an inert environment. The dissolution study was conducted in a temperature range of 20–120 °C in different solvents. The concentration profiles of fructose, 5-(hydroxymethyl)furfural (HMF), 5-(butoxymethyl)furfural (BMF) and BL were analyzed in different solvents: butanol/water, butanol, butanol/GVL/water and butanol/GVL. We found that using a butanol/GVL (70/30 wt%) solvent is better from the conversion and dissolution viewpoints.