Ionic liquid dissolution utilized for biomass conversion into biofuels, value-added chemicals and advanced materials: A comprehensive review

Lignocellulosic and algal biomass feedstocks are the most plentiful and cost-effective renewable sources of biofuels (sugar, bioethanol, biodiesel, and bio-oil), value-added chemicals (organic compounds), and advanced materials (hydrogels and composites). The lignin, cellulose, and hemicellulose complex's recalcitrance, which leads to ineffective conversion into valuable compounds, is one of the most significant challenges in biomass valorization. Some ionic liquids (ILs) have been shown to be efficient decomposers of lignocellulosic and algal biomass. In reality, ILs offer a unique green alternative compared to harmful volatile organic solvents and severe process conditions. Enhanced productivity in the conversion of biomass feedstocks could result from advancements in IL-based pretreatment technologies. The capability of the different types of ILs for conversion, as well as the impact of different properties and operating parameters, are comprehensively reviewed and discussed in this paper. The known methods for the dissolution of three main components of lignocellulosic and algal biomass with ILs are also described. Furthermore, the challenges to be addressed when utilizing IL for biomass pretreatment and processing on a commercial scale are highlighted. The significant promise of ionic liquids for this objective is anticipated to stimulate research and lead to considerable technological advancements in this field.