Synergism of ionic liquids and lipases for lignocellulosic biomass valorization

Lignocellulosic biorefinery processes used to produce bioenergy and value-added products are technologically complex, expensive, energy-demanding, and often not environmentally friendly. Expansion of new value-added products produced in the existing biorefinery is hampered by a lack of efficient and, at the same time, sustainable technologies. Therefore, there is a strong need to develop novel technologies and/or create synergies between existing technologies to convert lignocellulosic biomass into value-added products in a sustainable manner. In this paper, solutions for cascade processes to convert lignocellulosic biomass into value-added products using ionic liquids and lipases are investigated. First, the chemical composition of lignocellulosic biomass and basic principles of solid-state fermentation are summarized. Then, an overview of lipase production by solid-state cultivation of microorganisms on lignocellulosic biomass is given. Additionally, the use of ionic liquids for lignocellulosic biomass valorization is discussed, followed by an overview of lipase-catalyzed biotransformation in ionic liquids in batch reactors and microreactors. At the end, a sustainability assessment of the synthesis of three selected ionic liquids and six lipase-catalyzed biotransformation in ionic liquids was performed using green chemistry metrics.