期刊名称：Journal of Materials and Environmental Science
印刷版ISSN：2028-2508
出版年度：2017
卷号：8
期号：8
页码：2619-2631
出版社：University of Mohammed Premier Oujda
摘要：Alfa is an interesting source for ethanol production; this abundant raw material has a highcellulose content. The aim of this study is to optimize the thermomechanical pretreatmentconditions applied to Alfa (Stipa Tenacissima) fibers that maximize by enzymatichydrolysis the conversion of biomass to fermentable sugars. The thermomechanicalprocess used in this study involves subjecting the lignocellulosic biomass for a fixed time(30 min) to saturated steam pressure (0.7 MPa), followed by a flash decompression tovacuum pressure (50 mbar). The heat induced by saturated steam result in intensive vaporformation in the capillary porous structure of the plant material and the shearing forcesdue to the subsequent pressure release that damage the cellulosic biomass structure,making it more accessible to the attack by enzymes. Prior to pretreatment, the substratewas impregnated by spraying with H2SO4 and NaOH catalysts with concentration rangingfrom 0 to 15 wt%. Unwashed alkali and acid substrate were hydrolyzed using Celluclast1.5 L (480 FPU/L). Acid catalyzed pretreatment of the biomass resulted in an efficientdegradation of cellulose and hemicellulose by increasing recovery of reducing sugarsbefore (R1) and after enzymatic hydrolysis reactions and improving the specific surfacearea. R1 varied from 0.88 g/L (uncatalyzed raw material) to 1.90 g/L (treated Alfa with 15wt%). The maximum yield of reducing sugars of 95% was obtained at 5 wt% of sulfuricacid while the amount of sugars released after enzymatic hydrolysis was not affected bythe presence of sodium hydroxide.
