Physicochemical transformation and enzymatic hydrolysis promotion of reed straw after pretreatment with a new deep eutectic solvent

This work proposed a promising biorefinery method for the deconstruction of reed straw by using a novel deep eutectic solvent (DES) consisted of benzyltriethylammonium chloride/formic acid (BTEAC/FA). BTEAC/FA showed significant delignification and xylan removal while preserving most of the cellulose. Under the optimum conditions (molar ratio: 1:6), the glucose yield of cellulose-rich substrates by enzymatic hydrolysis reached 76.64%, which was about 5.24-fold higher than that of raw reed straw. The removal of lignin and hemicellulose and the changes in the cellulose crystal structure were presumed to the reason for enhancing enzymatic hydrolysis efficiency. The highest lignin yield reached 78.34%. Moreover, the lignin exhibited high purity (84.25%-91.45%), medium molecular weight (3812-9918 g/mol), and low polydispersity (1.47-2.75) because of the cleavage of β-O-4 and β-β linkages. Overall, this work provided a theoretical basis for the in-depth utilization of reed straw.