A two-stage pretreatment process is proposed in this research in order to improve sugar recovery from corn stover. In the proposed process, corn stover is hydrolyzed by dilute hydrochloric acid to recover xylose, which is followed by a Fenton reagent oxidation to remove lignin. 0.7 wt% dilute hydrochloric acid is applied in the first stage pretreatment at 120 degrees C for 40 min, resulting in 81.0% xylose removal. Fenton reagent oxidation (1 g/L FeSO4 center dot 7H(2)O and 30 g/L H2O2) is performed at room temperature (about 20 degrees C) for 12 has a second stage which resulted in 32.9% lignin removal. The glucose yield in the subsequent enzymatic hydrolysis was 71.3% with a very low cellulase dosage (3 FPU/g). This two-stage pretreatment is effective due to the hydrolysis of hemicelluloses in the first stage and the removal of lignin in the second stage, resulting in a very high sugar recovery with a low enzyme loading. (C) 2016 Elsevier Ltd. All rights reserved.