Microwave-assisted choline chloride/lactic acid pretreatment for high-efficiency separation and value-added utilization of Sugarcane bagasse components

The development of non-waste biorefinery technology is conducive to the efficient utilization of waste biomass resources. In this study, the microwave-assisted deep eutectic solvent (DES) was used to pretreat sugarcane bagasse for efficient separation of chemical components and upgrading each component into industrial products, including paper, lignin microspheres (LMS) and furfural . After rapid and mild DES pretreatment at 135 °C for 20 min, the retention rate of cellulose in the solid residue was 95.2 %, while the removal rates of hemicellulose and lignin were 84.1 % and 88.3 %, respectively. The whiteness of handmade paper derived from solid residue could reach 63.8 %ISO. During DES fractionation, the gradual increase of water reduced the collision probability of lignin fragments, inhibited condensation reactions , and achieved graded precipitation of lignin. Then, the self-assembly method enabled the fabrication of both small solid LMS and large hollow LMS. Furthermore, AlCl 3 was added to the diluted DES to convert the separation system into a catalytic system. Under the synergistic catalysis of lactic acid, AlCl 3 , and choline chloride, biomass sugars were efficiently converted into furfural with a yield of 68.81 %. In a word, the high-value utilization of all components of sugarcane bagasse was achieved through a sustainable biorefining process, resulting in an impressive comprehensive utilization rate of 70.6 %.