초록
<P><B>Abstract</B></P> <P>Olive tree biomass (OTB) can be used for producing second generation bioethanol. In this work, extracted OTB was subjected to fractionation using a sequential acid/alkaline oxidative pretreatment. In the first acid stage, the effects of sulfuric acid concentration and reaction times at 130°C were investigated. Up to 71% solubilization of hemicellulosic sugars was achieved under optimized conditions (2.4% H<SUB>2</SUB>SO<SUB>4</SUB>, 84min). In the second stage, the influence of hydrogen peroxide concentration and process time were evaluated at 80°C. Approximately 80% delignification was achieved under the best operational conditions (7% H<SUB>2</SUB>O<SUB>2</SUB>, 90min) within the experimental range studied. This pretreatment produced a substrate with 72% cellulose that was highly accessible to enzymatic attack, yielding 82g glucose/100g glucose in delignified OTB.</P> <P>Ethanol production from both hemicellulosic sugars solubilized in the acid pretreatment and glucose from enzymatic hydrolysis of delignified OTB yielded 15g ethanol/100g OTB.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Sequential pretreatment acid/alkaline-peroxide of OTB is assessed for the first time. </LI> <LI> The two-step pretreatment enabled the fractionation of OTB. </LI> <LI> Alkaline peroxide delignification selectively removed the lignin fraction. </LI> <LI> Yields are better than those reported for this feedstock by other methods. </LI> </UL> </P>