LAUSR

Selective lignin depolymerization (SLD) has emerged as a value-added method of pretreatment for lignocellulosic biorefining, in which lignin is depolymerized into valuable phenolic monomers prior to utilization of the hemicellulose and cellulose. Herein, we report a biomimetic Fenton catalyzed SLD process, converting sweet sorghum bagasse into an organic oil that is rich in phenolic monomers and a solid carbohydrate that is favorable for enzymatic hydrolysis into sugars. Initially, the feedstock’s molecular structure was modified through iron chelation and free radical oxidation via Fenton’s reagent (Fe3+, H2O2). The lignin component of the modified feedstock was then selectively depolymerized in supercritical ethanol (250 °C, 6.5 MPa) under nitrogen to produce a phenolic oil, with a maximum yield of 75.8 wt %. Six valuable phenolic monomers were detected in this oil, with a maximum cumulative yield of 19.1 wt %. The solid carbohydrate obtained after the SLD process was enzymatically hydrolyzed to liberat...