Pretreatment of corncob powder by choline chloride-urea-ethanolamine to co-produce glucose, xylose and lignin nanospheres

A ternary deep-eutectic solvents (DESs) which consisted of choline chloride-urea-ethanolamine (ChCl-U-EOA) was used for the pretreatment of corncob powder (CCP), and the effect of various pretreatment conditions on the pretreated substrates components and subsequent enzymatic digestion was investigated. The results indicated that under the optimum pretreatment conditions (110 ℃, 60 min, 10% solid concentration), the ChCl-U-EOA pretreatment could selectively remove ∼71.8% of lignin while retaining ∼87.7% of cellulose and ∼74.6% of hemicellulose , and the yields of glucose and xylose after enzymatic digestion reached ∼86.4% and ∼70.5%, respectively. The characterization of various pretreated substrates showed that the removal of lignin, and the fragmentation of pretreated substrates was the key factors to improve glucose/xylose yields. In addition, the lignin in the pretreated hydrolysate was collected by acid precipitation and fractionated by ethanol, and then lignin nanospheres (LNPs) with a particle size under 200 nm were fabricated via a solvent-antisolvent method.