Fractionation Of Olive Woody Waste (Oww) Obtained After Milling By Hydrothermal Pretreatments - Steam Explosion And Hot Water

The olive woody waste (OWWis a promising feedstock for biorefineries in the Mediterranean region. In order to valorize this lignocellulosic residue, a pretreatment is necessary to fractionate its components and to improve the cellulose enzymatic hydrolyzability. The work target was to compare the efficiency of two physicochemical pretreatments, viz.: Steam Explosion (SE) and Hot Water/OrganoSolv (OS) towards acid fractionation of OWW and enzymatic digestibility of the cellulosic residue. The SE pretreatment was performed with a batch reactor of 10 L, coupled with a 125 kW boiler. The biphasic Hot Water/OrganoSolv (OS) pretreatment was carried out with a high pressure and temperature batch reactor of a 0.5 1 vessel with adjustable internal stirrer and heat control. After SE and Hot Water/OrganoSolv (OS) pretreatments the materials were extracted by water to remove and quantify the soluble hemicellulose as monomers and oligomers as well as the inhibitors; the solid residue was saccharified. The digestibility of cellulose was very good in both cases, OS was slightly more effective in terms of sugars recovery.