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 degrees C. The solution forms an aerosol (droplet size of 30 mu m), 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 O-2 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 degrees C with HMF as a feedstock.

Automated summary

A new method for converting fructose into hydroxymethylfurfural (HMF) is proposed, achieving high yield with a gas-phase reactor and catalyst.