Contribution of Deep Eutectic Solvents for Biomass Processing: Opportunities, Challenges, and Limitations

Since their introduction in 2004, deep eutectic solvents (DESs) have attracted interest in different fields of chemistry. In the case of biomass, DESs are particularly interesting, not only because of their low cost and biodegradability, but also due to their unique property to interact with hydrogen-bond donors such as renewably sourced polyols or carboxylic acids. Through selected examples, we report the contribution of DESs for the dissolution of biomass, the extraction/purification of bio-derived chemicals, and the conversion of carbohydrates to furanic derivatives. In all examples, we discuss how the DES can impact the selectivity of a chemical process and the limitations associated with the use of DES. In particular, impact of the DES viscosity on extraction, the recovery and recycling of DES, and the stabilization of chemical intermediates in DES are among the key aspects that are discussed.