Improving corn stover enzymatic saccharification via ferric chloride catalyzed dimethyl sulfoxide pretreatment and various additives

•FeCl3-catalyzed dimethyl sulfoxide pretreatment was developed to enhance biomass hydrolysis.•The proposed pretreatment extract up to ˜100% hemicellulose and ˜36.4% lignin.•The highest glucose yield of 90.2% was obtained during subsequent hydrolysis.•Tween 80 showed great potential for reducing cellulase dosage and shorten hydrolysis time.