Pretreatment of corn stover for sugar production with switchgrass-derived black liquor

► Switchgrass-derived black liquor has a high pH and appreciable carbohydrate content. ► Black liquor is effective in pretreating corn stover at room temperature. ► A carbohydrate conversion of 66.2% can be achieved by using black liquor within 24 h. ► Black liquor is comparable with 1% NaOH in corn stover pretreatment. ► Further recycling of black liquor is possible with alkalinity supplementation.