Pt-WO3 oxydehydrates fructose to furans in the gas phase

Bio-feedstocks are destined to replace fossil fuels for specialty chemicals, but current bio-refineries mainly ferment monosaccharides to ethanol, a commodity chemical that is blended with gasoline as a fuel. The market price of biofuels is several-fold lower than specialty chemicals and monomers. Rather than cracking the C6-sugars ethanol, here, develop dehydration and oxydehydration processes to valuable platform C6-chemicals like 5-hydroxymethyl furfural (HMF), 2,5-dimethyl furan (DFF), and 2,5-furandicarboxylic acid. This gas-phase process atomizes an aqueous solution of fructose into a fluidized bed reactor operating at 350 ◦C. The solution forms an aerosol (droplet size of 30 μm), which contacts the hot Pt-WO3/TiO2 catalyst and reacts to HMF rather than caramelizing. The maximum yield reached 21% and it increased slightly with temperature, and decreased with increasing catalyst inventory; it was less sensitive to O2 concentration, Pt loading on the catalyst, liquid feed flow rate, and fructose feed concentration. At the optimal condition, selectivity continued to increase with time even after 3 h reaction. Selectivity to 2,5-diformyl furan reached 42% at 250 ◦C with HMF as a feedstock.