Fractionation of non-timber wood from Atlantic mixed forest into high-value lignocellulosic materials

The forestry industry in the Basque Country has experienced an abandonment of small-sized forests in which native and introduced species tend to regrow if unattended; thus, requiring an intervention under which proper forest management is implemented. This paper evaluates the potential fractionation of lignin and cellulose from six tree species coming from such mixed forests as a value-added use of wood discarded by logging within the frame of sustainable forest management. The species used were Northern red oak, common oak, common ash, Iberian white birch, sweet chestnut, and black locust. The different wood samples were treated with an Organosolv treatment and elemental chlorine-free bleaching to fractionate them to their main components, recovering the cellulose and the lignin. Cellulose was defibrillated via high-pressure homogenization to obtain cellulose nanofibers. The resulting lignin and cellulose nanofibers were analyzed. The results support the idea that this process offers the opportunity to treat different raw materials in the same process, with corresponding possible economic benefits.