5-Hydroymethylfurfural production from fructose dehydration in ionic liquid

In this paper,the effects of reaction time,temperature and the type of ionic liquids on the fructose hydration in ionic liquids to 5-hydroymethylfurfural(5-HMF)were investigated,in which the six 1-butyl 3-methyl imidazolium(+) ionic liquids with different anions(Cl-,Br-,[CF3COO]-,[BF4]-,[ H2SO4]-,[ H2PO4]-) were used as solvents and catalysts.The results showed that fructose conversion and 5-HMF yield increased with the increase of reaction time and temperature.However,the longer time and higher temperature decreased reaction selectivity of 5-HMF.Lewis acidic ionic liquid acts more effectively during producing 5-HMF from fructose hydration than Bronsted acidic.Condensation and polymerization among molecules are restrained in presence of Cl-anion of ionic liquid,and results in the advanced reaction selectivity.With Cl as the solvent and catalyst,in the case of 120℃ and 120 min,fructose conversion of 94.4 wt% and 5-HMF yield of 70.8 wt% can be obtained.