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 physico-chemical 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 l 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.
Proceedings of the 26th European Biomass Conference and Exhibition, 14-17 May 2018, Copenhagen, Denmark, pp. 1115-1117