Pretreatment Of Sugarcane Bagasse With Mixed Sodium Phosphate And Hydrogen Peroxide

Sugarcane bagasse?SCB?is an important renewable biomass resource.However,it is difficult to achieve effectively enzymatic hydrolysis by cellulases for its natural recalcitrant structure.Therefore,an effective pretreatment method is necessary to improve enzymatic efficiency.In this study,sodium phosphate?Na₃PO₄?and hydrogen peroxide?H₂O₂?were combined to pretreat SCB.First,the effects of Na₃PO₄ pretreatment alone on SCB was investigated.Then mixed Na₃PO₄ and H₂O₂ pretreatment on SCB was investigated and the conditions of this pretreatment were optimized.Next,two stage pretreatment of Na₃PO₄-H₂O₂and H₂O₂-Na₃PO₄order were compared with mixed reagents.And the structure of raw and pretreated SCB were analyzed.Finally,the fermentation of pretreated SCB using Saccharomyces cerevisiae 1445 strain was carried out to convert it into ethanol.The sodium phosphate alone pretreatment showed that 8%sodium phosphate had best results in enzymatic hydrolysis.The optimal conditions were mixing 8%Na₃PO₄and 2%H₂O₂ and pretreating sugarcane bagasse at 121 ^oC for 60 min.Under these conditions,the lignin removal rate and enzymatic efficiency were 84.17%and 82.22%,respectively.Two-stage pretreatment processes of Na₃PO₄-H₂O₂and H₂O₂-Na₃PO₄ could improve the lignin removal rate but obtain lower enzymatic efficiency compared with mixed Na₃PO₄ and H₂O₂ pretreatment.Structural analysis of SCB showed the surface structure of pretreated SCBs were seriously damaged comparing with raw SCB.Mixed Na₃PO₄ and H₂O₂ pretreatment on SCB showed the worst structural damage,the highest crystallinity and the lowest unsaturation.Fermentation of SCB to produce ethanol was performed using S.cerevisiae.1445.In the separate hydrolysis and fermentation?SHF?,the highest ethanol concentration could reach 3.55g/L,and the ethanol yield was 116.78 g/kg raw SCB.In the simultaneous saccharification and fermentation?SSF?,the highest ethanol concentration could reach 2.42 g/L and the ethanol yield was 79.60 g/kg raw SCB.In summary,mixed sodium phosphate and hydrogen peroxide pretreatment could be a green,feasible and effective method for biomass biorefinery.