Amine-based pretreatments for lignocellulose fractionation and lignin valorization: a review

Abstract

The increasing demand for sustainable bioproducts as alternatives to fossil-based resources requires unremitting endeavor for the advancement of lignocellulose valorization. In this respect, the robust pretreatment of lignocelluloses has been deemed as an essential process for high component fractionation performance to facilitate downstream upgrading. This review thereby presents the current state-of-the-art amine-based pretreatments of lignocellulosic biomass. The pretreatment role as well as the concept and features of amine-based pretreatment is first described to ensure the effectiveness of component fractionation and biorefinery of lignocelluloses. A deep mechanistic understanding of pretreatment and its performance is fully described to aid in achieving a high yield of fermentable sugars while leaving preferred lignin for further upgradation. Furthemore, numerous amine solvent systems of pretreatment are reviewed to present their potential benefits in the fractionation process with effective separation of interlinked lignocellulose components, yield and the quality of fractionates. Moreover, some existing challenges and perspectives are indicated to highlight opportunities within this captivating technology. Amine-based pretreatment could be a promising approach with distinct beneficial attributes on lignocellulose conversion and lignin valorization.