The full utilization of bagasse via deep eutectic solvent pretreatment for low-condensed lignin and cellulose smart indicator film

Abstract

Full utilization of biomass after fractionation of its components is an effective way to maximize the value of biomass. Herein, in this study, a new acetal-mediated deep eutectic solvent (DES) was explored and its excellent performance in separating lignin from biomass as well as retarding lignin condensation has been observed. Subsequently, the separated lignin and cellulose-rich residue were used to prepare sunscreen and transparent food indicator films, respectively. The results showed that the acetal-mediated DES pretreatment can reduce the recalcitrance of bagasse, stabilize lignin (β-O-4 content of 68.87% in the lignin), and retain most of the cellulose (ie. 83.5%). Besides, the pretreatment enhanced the subsequent hydrogenolysis of lignin, and the higher β-O-4 content of the lignin contributed to the high yield of aromatic monomers (40.94%). In addition, regenerated lignin was attractive for sunscreen applications due to its lighter color and excellent UV-blocking properties. Furthermore, cellulose smart indicator film was highly sensitive, biodegradable, has excellent physical properties, and allows visual real-time monitoring of seafood spoilage using smartphones. Meanwhile, the yield of the removed hemicellulose converted to xylose in the pretreatment process reached 99.41%. In general, this work proposed a sustainable bio-refinery approach for the full upgrading of biomass.