Activation of lignocellulosic biomass by ionic liquid for biorefinery fractionation

► Ionic liquid, 1-ethyl-3-methylimidazolium acetate, is capable of at least partially dissolving biomass. ► 1-Ethyl-3-methylimidazolium acetate under mild conditions deacetylates and decreases biomass crystallinity. ► Through an IL activation phase, Yellow poplar becomes less recalcitrant and cellulose easily hydrolyzable. ► Strong correlation exists between acetyl content and biomass hydrolyzability.