Pretreatment technologies for valorisation of lignocellulosic biomass towards sustainable biorefineries: Comprehensive insights and advances

Lignocellulosic biomass (LCB) is a sustainable feedstock for fuels and other products, however bioconversion is challenging due to its recalcitrant structure. Pretreatment offers an effective solution for fractionating LCB into their constituent polymers (cellulose, hemicellulose, and lignin). These polymers can be further converted into fuels and other industrial products. However, conventional pretreatment techniques (physical, physicochemical, chemical and biological) either fails to efficiently fractionate LCB into intact components or their industrial scale application is challenging. Unlike existing reviews, this study not only discusses conventional pretreatment strategies, but also it comprehensively highlights emerging pretreatment technologies (using ionic liquids and deep eutectic solvent), their chemical mechanism and industrial challenges. Additionally, this study also highlights the integration of technoeconomic analysis for analysing industrial feasibility of pretreatment methods, and the strategies for utilisation of emerging computational tools such as Artificial Intelligence and Machine learning for development of sustainable and economic LCB-based biorefinery for bioproducts.