(477d) Develop Deep Eutectic Solvent Systems for the Effective Fractionation of Lignin

Lignin is the second most abundant biopolymers in nature. The lignin content in softwoods is about 15 to 30wt% and 20 wt% in hardwoods. The lignin is currently underutilized because of a high heterogeneity in its structure. To utilize the great potential of this material fully, there is a need to develop an effective method that is economically and environmentally sustainable for producing lignin fractions with a more homogenous structure. In this work deep eutectic solvent systems with a lower viscosity will be developed, and its effectiveness in fractionating lignin will be studied. These novel deep eutectic solvents are characterized by measuring their melting point depression and the activity coefficients of each component in the system. Also, these solvents are further be characterized using the FT-IR technique. To understand the relationship between the solvent polarity of deep eutectic solvent systems and the chemical structure of the resulting lignin fractions, the collected lignin fractions and both the organosolv/native lignin are characterized using the NMR technique. The initial results indicated that both Organosolv and native lignin can be fractionated using the deep eutectic solvents with a low viscosity in two or more fractionation process steps. The solvent polarity of deep eutectic solvent is found to affect the physical properties of produced lignin fractions.