(631e) Consolidated Acid Catalysis and Extraction of Fermentable Sugars From Switchgrass in Ionic Liquids

Ionic liquids (ILs) continue to draw attention as a novel technology for the pretreatment of biomass. The realization of an economically-viable pretreatment technology requires the near complete conversion of biomass into its component sugars and a closed-loop use of the ionic liquid solvent. The IL 1-butyl-3-methyl imidazolium chloride ([C4mim]Cl) has been shown to greatly accelerate the rates of enzymatic hydrolysis of holocellulose into monomeric sugars, and has also been used to produce sugars in situ using mineral acids such as HCl. Recently we reported the use of boronic acids to recover sugars from an aqueous-IL phase into an organic phase. Using naphthalene-2-boronic acid (N2B) in solution with hexane and Aliquat 336?, more than 80% of the total sugars produced by the acid hydrolysis of switchgrass in a system of 1-ethyl-3-methyl imidazolium chloride ([C2mim]Cl) and hydrochloric acid could be extracted. Ionic liquids were recycled and used for subsequent treatment, hydrolysis and extraction with minimal loss of performance efficiency. This IL treatment process provides an alternative route to the production of monomeric sugars from biomass that may eliminate the need for saccharolytic enzymes, and could potentially provide an economical route to the production of biofuels and other biomass derived products.