Deep Eutectic Solvents and Their Use for Sustainable Pretreatment of Lignocellulosic Biomass

Lignocellulosic biomass (LCB) presents great potential to be used as a renewable and sustainable feedstock for the production of a variety of chemicals, biofuels, and bio-based products. However, the exploitation of this material is hindered by its complex and recalcitrant nature, which poses challenges in the efficient extraction and conversion of its components into value-added products. To address these challenges, deep eutectic solvents (DESs) have emerged as potential green chemistry solvents for LCB pretreatment and valorization processes. This chapter provides a comprehensive overview of DESs fundamentals, highlighting their potential significance as a sustainable pretreatment alternative for LCB. An in-depth explanation of DES concepts and recent advances in their application for biomass pretreatment, with a particular focus on extracting, solubilizing, and valorizing key LCB components is provided. The influence of diverse DES formulations and biomass feedstocks on pretreatment efficiency is also discussed. The chapter also explores DES recycling alternatives and elucidates the economic advantages associated with their use in biorefineries. Finally, this chapter also addresses the challenges and prospects for broader utilization of DESs, with potential to contribute to a more environmentally friendly and sustainable bio-based economy.