Efficient dehydration of glucose to 5-hydroxymethylfurfural catalyzed by the ionic liquid,1-hydroxyethyl-3-methylimidazolium tetrafluoroborate

The dehydration of fructose or glucose to 5-hydroxymethylfurfural (5-HMF) using room temperature ionic liquids (ILs) as a solvent is a promising method for producing liquid fuels from renewable resources. The IL, 1-hydroxyethyl-3-methylimidazolium tetrafluoroborate ([C2OHMIM]BF4), was used a catalyst-rather than as a solvent-in the conversion of fructose or glucose to 5-HMF. With glucose, the yield of 5-HMF reached as high as 67.3% after 1 h at 180 degrees C in dimethylsulfoxide (DIMSO) as solvent. The catalyst was separated from the reaction mixture by distilling solvent and reused six times without loss of activity. Furthermore, a kinetic analysis was carried out to illustrate the formation of 5-HMF, and the values of the activation energy and the pre-exponential factor for the reaction were 55.77 kJ mol(-1) and 1.6 x 10(4) min(-1) respectively. (C) 2012 Elsevier Ltd. All rights reserved.