(532e) Ionic Liquids and Biomass: Untangling Biomass Dissolution and Pretreatment Efficacy

The most frequently used ionic liquids (ILs) for biomass pretreatment are 1-ethyl-3-methylimidazolium acetate ([C2mim][Ac]) and 1-butyl-3-methylimidazolium chloride ([C4mim][Cl]). These two ILs induce different structural and compositional changes of biomass components, however, resulting in varied enzyme digestibility of the pretreated material. To more fully understand this, four ILs ? [C2mim][Ac], 1-ethyl-3-methylimidazolium chloride ([C2mim][Cl]), 1-butyl-3-methylimidazolium acetate ([C4mim][Ac]) and ([C4mim][Cl]) ? have been used to explore how the ion structure affects the dissolution and fractionation process of biomass components. In particular, the carbohydrate yield after pretreatment, separation/utilization of non-carbohydrate components and recycleability of the ILs are critical factors influencing the practical application of ILs for biomass pretreatment. This research is crucial for defining an effective dissolution and fractionation process for corn stover and other biomass feedstocks based upon IL properties, cellulose dissolution ability, fractionation efficiency of biomass components, and enzyme digestibility of the pretreated materials.