Hydrogen Peroxide-assisted Sodium Carbonate Pretreatment For The Enhancement Of Enzymatic Saccharification Of Corn Stover

With the increasing of energy requirement around the world and the depleting of fossil fuels, the exploration and development of renewable energy alternatives have become impending. Biofuels and biomaterials produced from agricultural resdues have been extensively studied in recent years. However, the efficiency of enzymatic saccharificaion is limited by nature recalcitrance of lignocelluloses. Therefore, cost-effective and green pretreatment of lignocelluloses is needed to remove these obstacles to improve the downstream enzymatic saccharification. In this paper, the effectiveness of hydrogen peroxide-assisted sodium carbonate pretreatment of corn stover to produce fermentable sugars was investigated. The main contents of this study were as follows:Firstly, in this work, the impact of main composition changes and enzymatic saccharification of corn stover after sodium carbonate pretreatment were investigated. As a result, the suitable sodium carbonate dosage for SC pretreatment was 40%; under such conditions, the lignin removal and retention rate of carbohydrate were 56.3%and 92.7%, respectively. The corresponding final total sugar yield after PFI refining was 72.4%, which was more efficient than corn stover without pretreating.Secondly, the hydrogen peroxide-assisted sodium carbonate (HSC) pretreatment of com stover to produce fermentable sugars was explored. The impact of Na2CO3 and H2O2 dosages on the effectiveness of HSC pretreatment was studied. The suitable Na2CO3 and H2O2 dosages for HSC pretreatment were 40 wt% and 15 wt%, respectively. Under such conditions, the glucan and xylan yields could reach 88% and 63%, respectively. The corresponding final total sugar yield was 79%, which was about 10% higher compared to SC pretreatment. Also, the lignin removal (in the range of 12-65%) was linearly and positively correlated with the final total sugar yields.Finally, the enzymatic hydrolysis of HSC pretreated corn stover was optimized, and the optimal enzymatic hydrolysis conditions were:solid content 2-6%, temperature 50?, pH 4.4-5.5, cellulose dosage 20 FPU/g-substrate, ?-glucosidase dose 5 IU/g-substrate, xylanase dosage 5 U/g-substrate and enzymatic hydrolysis duration 48h.