Biobased materials and chemicals from industrial bark and willow by optimized processes

Bark is an abundant but underutilized industrial biomass side stream with potential to be applied as raw material for a wide range of end products. Softwood bark contains polyphenols and other functional components in addition to polysaccharides and lignin, while for birch the most relevant components to be valorized are suberin and betulin in the outer bark fraction. Willow bark is a potential future raw material source. Its industrial utilization requires, however, development of a suitable debarking method.
Alkaline cooking and hot water extraction of softwood bark will be tested as alternative process concepts. The produced tannin fractions will differ in their properties, and thus the most feasible end uses will be identified for each type. Cationic tannin flocculants, tannin-based adhesives and surfactants will be the target end products for softwood bark. For birch bark, functional coatings are the target products. Each value chain will be supported by RTO and industrial partners. An overall concept for the willow biorefinery will be developed by an industrial partner, starting from cultivated willow and comprising debarking and separate conversion of the bark and stem wood fractions into marketable products.