Glucose isomerization in dioxane/water with Sn-β catalyst: improved catalyst stability and use for HMF production

Abstract

The stability of zeolite Sn-beta (Sn-β) was greatly improved for glucose isomerization to fructose and fructose yield of 41.5% has been obtained when dioxane/water was used as solvent. The effect of dioxane/water solvent mixtures for fructose dehydration on Amberlyst-131 was also studied and it was found that small amounts of water in dioxane increase the yield of HMF (up to 74%) by limiting the formation of oligomers like difructose anhydride (III). 56% yield of HMF from glucose, maltose, trehalose or cellobiose and 60% from sucrose were produced when hydrolysis of disaccharides, glucose isomerization and fructose dehydration were coupled in a mixture of dioxane/water (5 wt%).