Production of furfural from biomass

A process comprising:

• a) providing an aqueous solution comprising a metal halide, a water-miscible organic solvent, a mineral acid, and water;
• b) providing a feedstock comprising at least one selected from:
• i) lignocellulosic feedstock containing glucan and xylan,
• ii) hemicellulosic material,
• iii) C5 sugar monomers and —C5 oligomers;
• c) contacting the feedstock with the aqueous solution to form a reaction mixture, wherein
• i) the concentration of water-miscible organic solvent is from about 10 weight percent to about 80 weight percent,
• ii) the concentration of metal halide is from about 0.1 weight percent to about 2 weight percent,
• iii) the mineral acid concentration is from about 0.5 to about 4 weight percent;
• and
• iv) the feedstock is present at about 1 to about 50 weight percent,
• wherein the weight percentages are based on the total weight of the reaction mixture;
• and
• d) heating the reaction mixture at a temperature in the range of about 140° C. to about 190° C. for a time sufficient to effect a reaction to produce furfural, wherein the aqueous solution remains monophasic at the reaction temperature and at the completion of the reaction.