Pretreatment of sugarcane bagasse with acid catalyzed ethylene glycol–water to improve the cellulose enzymatic conversion

[Display omitted] •Sugarcane bagasse was pretreated by acid catalyzed ethylene glycol-H2O (HCl/EG-H2O).•About 90% xylan and 61% lignin were selectively extracted by HCl/EG-H2O pretreatment.•Both Tween 80 and BSA showed extraordinary ability to improve hydrolysis efficiency.•The maximum cellulose enzymatic conversion of this work was 88.7%.•About 39.2% lignin could be recovered from the HCl/EG-H2O pretreatment spent liquor. In this work, HCl catalyzed ethylene glycol–water pretreatment (HCl/EG-H2O) of sugarcane bagasse (SCB) was explored with response surface methodology (RSM) and single factor analysis, which aim to investigate the influence of pretreatment variable on pretreated solid cellulose enzymatic conversion. The result showed that HCl/EG-H2O pretreatment could selectively extract ∼89.9 % xylan and ∼61.2 % lignin in SCB, meanwhile maintain a relatively high cellulose retention (∼86.8 %). Pretreatment of SCB at 120 °C for 60 min with 1.00 % HCl and 90 % EG obtained the pretreated solid having maximum cellulose enzymatic conversion of 88.7 % under 10 FPU/g enzyme dosage, this enhancement of cellulose enzymatic conversion mainly attributed to structure change of SCB in pretreatment. The adding of enzymatic additives into the hydrolysis process could not only improve hydrolysis efficiency but also lower the enzyme dosage. Besides, the linear relationship between substrate characteristic parameters (such cellulose content, lignin removal rate etc.) and cellulose conversion were observed.