Facile fractionation of lignocellulosic biomass: a review on promising green technology of deep eutectic solvent for bioethanol production

Sustainable bioethanol production from lignocellulosic biomass to meet the energy demand and generate wealth from waste is the need of the hour. A surplus amount of lignocellulosic biomass is produced worldwide as organic waste which can be utilized for bioethanol production. Pretreatment is a crucial step in biorefinery application, the selection of the best pretreatment technology will reduce the intensive energy requirements, and the operational costs make biofuel production economically feasible and sustainable. Every pretreatment technology has its own drawbacks which needs to be addressed. Among these technologies, deep eutectic solvent (DES) is being investigated as an ideal solvent for the pretreatment of lignocellulosic biomass to improve the enzymatic digestibility, surface area solubility, and lowering lignin content and cellulose crystallinity. DES offers a green way of deconstructing lignocellulosic biomass with minimum environmental hazard. DES is an inexpensive and environment-friendly solvent effective in biomass valorization. This review focuses on the current status and advancements in pretreatment technologies using DES and its future prospects.