BIOMASS CONVERSION AND BIOREFINERY, cilt.13, sa.8, ss.6471-6479, 2023 (SCI-Expanded)
Pretreatment is extremely required in lignocellulosic bioethanol production to improve enzymatic digestibility of biomass by disrupting lignin structure, reducing cellulose crystallinity, and increasing biomass porosity. The aim of this study was to evaluate the effects of different chemical pretreatments (dilute acid, alkaline, and sequential dilute acid/alkaline) for the conversion of miscanthus biomass to fermentable sugars. Pretreatments were performed in an autoclave at 121 degrees C for 30 and 60 min. Sequential dilute sulfuric acid (H2SO4)/sodium hydroxide (NaOH) pretreatments caused the highest lignin removal (80.2-93.1%) but the lowest solid recovery (28.7-34%) among the pretreatments. Additionally, the dilute H2SO4 pretreatments induced significantly lower hemicellulose recovery than the NaOH and lime (Ca(OH)(2)) pretreatments. On the other hand, the significantly highest theoretical ethanol yield (206.8 mg g(-1) raw material) was achieved when the biomass was subjected to 1% NaOH (w/v) pretreatment for 30 min, primarily due to its high sugar production (613.3 mg g(-1)) and moderate solid recovery (66.1%). These results indicated that the NaOH pretreatment was the most promising option among the chemical pretreatments tested to ensure sustainable bioethanol production from miscanthus.