Acid catalysis has also been used to produce sugars and other high value compounds in situ through the acid catalyzed hydrolysis of biomass dissolved in imidazolium chloride ILs. Acid catalysts have been used previously to hydrolyze polysaccharides into fermentable sugars during IL pretreatment. This could potentially provide a means of liberating fermentable sugars from biomass without the use of costly enzymes. However, the separation of the sugars from the aqueous IL and recovery of IL is challenging and imperative to make this process viable.
In this work, we use a novel solution to induce the formation of a biphasic system from a concentrated solution of sugars produced by the acid catalyzed hydrolysis of switchgrass in the IL 1-butyl-3-methylimidazolium chloride. The biphasic system allows for the easy recycling of IL and recovery of the sugars. This process provides an alternative route to the production of monomeric sugars from biomass that eliminates the need of enzymes, and reduces the amount of water required by the process.