Tuesday, May 3, 2011
Ionic liquids (ILs) have some advantages when applied for biomass pretreatment, but require the recovery and reuse of the IL because of their relatively high cost. In this talk we present a new method for recovering the ionic liquid 1-ethyl-3-methylimidazolium acetate and the solutes present from the pretreatment of corn stover. The process utilizes a phase-switchable solvent system containing ketones, alcohols, IL, and water and provides a facile route for the recovery of dissolved lignin, nonpolar substances, and low molecular weight sugars from the IL to enable IL recycle. We demonstrate a solids recovery of 83% of initial solids and IL recovery of 89% from the pretreatment of 100 g of corn stover. Recovered products are characterized by 2-D NMR, and mass balance is provided for the entire process.