Doctoral Project

Hemicellulose Extraction from spruce wood chips
(Topic A.5)

– Getting the best out of wood –

The three main components in wood are lignin, cellulose and hemicellulose. Cellulose as structural substance serves in the living tree to take up tractive forces, lignin as filler substance in the cellulose structure takes up compressive forces, and hemicelluloses as binder between cellulose and lignin provide flexibility.
When particle boards are used in humid conditions, e.g. in the kitchen or in the bath, the high humidity can lead to swelling and shrinking of the particle board. This effect occurs most likely due to the hydrophilic hemicelluloses with their free hydroxyl groups, which can easily take up water. The extraction of hemicelluloses can counteract this effect.
If the hemicellulose extraction is done under gentle conditions, the natural synthesis output can be preserved. Like this it is possible to extract more or less long hemicellulose chains. These hemicelluloses can be used as additional product, which heightens the used lignocellulosics resource efficiency. Hemicelluloses are already used, e.g. in the food industry as dietary supplement. There is also some research whether the hydrophilic properties of hemicelluloses can be used in other ways, e.g. for water storage.
This work searches for extraction conditions leading to high molecular weight hemicelluloses, defines the properties of the extracted hemicelluloses and how the extraction effects properties of particle boards made out of extracted spruce wood chips.
The goal is to extract high molecular weight hemicelluloses and to produce particle boards with partially improved properties.