Conversion of Glucose to 5-Hydroxymethylfurfural, Levulinic Acid, and Formic Acid in 1,3-Dibutyl-2-(2-butoxyphenyl)-4,5-diphenylimidazolium Iodide-Based Ionic Liquid

The separation process between 5-hydroxymethylfurfural (HMF) and trace glucose in glucose conversion is important in the biphasic system (aqueous-organic phase), due to the partial solubility property of HMF in water. In addition, the yield of HMF via the dehydration reaction of glucose in water is low (under 50%) with the use of Bronsted acid as a catalyst. Therefore, this study was conducted to optimize the production and separation of products by using a new hydrophobic ionic liquid (IL), which is more selective than water. The new IL (1,3-dibutyl-2-(2-butoxyphenyl)-4,5-diphenyl imidazolium iodide) [DBDIm]I was used as a solvent and was optimized for the dehydration reaction of glucose to make a more selective separation of HMF, levulinic acid (LA), and formic acid (FA). [DBDIm]I showed high performance as a solvent for glucose conversion at 100 degrees C for 120 min, with a yield of 82.2% HMF, 14.9% LA, and 2.9% FA in the presence of sulfuric acid as the Bronsted acid catalyst.