Solubility of Glucose in Ionic Liquid + Antisolvent Mixtures

An extended study on the solubility of glucose in ionic liquid (IL) + antisolvent mixtures has been performed to find a way to separate glucose from ILs. These ILs, commonly used in cellulose conversion processes, are based on combination of cations of 1-methyl-3-alkylimidazolium and anions of chloride, bromide, acetate, and hydrogen sulfate. Effects of temperatures, antisolvents, ILs, mass ratios of antisolvent to IL, and water contents on the solubility of glucose have been investigated in this work. The results demonstrate that the solubility of glucose increases with decreasing mass ratio of antisolvent to IL and elevating temperatures. The solubility of glucose in IL + ethanol mixtures increases in the following order: [emim][Br], [bmim][Cl], [hmim][HSO4], [bmim][CH3COO], and [emim] [CH3COO]. The addition of water can increase the solubility of glucose in IL + antisolvent mixtures. Ethanol can be selected as a better antisolvent to separate glucose from IL than methanol, acetone, and acetonitrile.