Bachelor Assignments

Screening of deep eutectic solvents for liquid-liquid extraction

Bachelor assignment: screening of deep eutectic solvents for liquid-liquid extraction

Coach: Dion Smink, MSc

Recently, a new class of solvents was developed called ‘Deep Eutectic Solvents’ (DES). These new solvents have interesting properties, like a negligible vapour pressure, non-flammability and can be bio-based. One application of DES which is currently investigated is the removal of lignin from biomass to produce paper or other cellulose derived products.

After delignification the lignin must be removed from the DES. The current state of the art technology is the precipitation of lignin by the addition of water, which must be boiled off later. This step requires too much energy for industrial applications. Therefore liquid-liquid extraction of lignin from DESs with an organic solvent is under investigation.

It is your task to screen a number of DES-solvent combinations for this application. You will therefore make a number of these DESs simply by combining their constituents and determine their applicability for liquid-liquid extraction with a series of organic solvents. You will investigate which combinations of DESs with organic solvents are miscible and which form two liquid phases. For the combinations that form a two phase system you will investigate the amount of leaching from solvent to DES phase and vice versa.

Furthermore, the equilibrium partitioning of lignin between the DES and solvent should be investigated.