Comparison of the effects of five pretreatment methods on enhancing the enzymatic digestibility and ethanol production from sweet sorghum bagasse

► Dilute NaOH solution autoclaving and H2O2 immersing pretreatment is suitable for sweet sorghum bagasse pretreatment. ► The cellulose content was increased, and the hemicellulose and ADL lignin contents were decreased. ► The cellulose hydrolysis yield and total sugar yield were enhanced. ► Significant molecule and surface structure changes of the pretreated bagasse were found.