Pre-extraction of biomass is performed within UNRAVEL to upgrade the biomass by removal of the non-lignocellulosic parts such that the lignocellulosic content is more pure. This method has proven benefits for the subsequent fractionation and downstream processing but will increase the costs of the biorefinery processes. Therefore, it is interesting to also target the purification and valorization of valuable compounds from biomass.
Within UNRAVEL we have targeted betulin from birch bark as an interesting compound as it was found in relatively high concentrations (8.8%) in this species. Betulin is a naturally occurring terpene which gives the outer part of the birch trunk its white colour to protect the tree from mid-winter overheating by the sun. Betulin is a compound of interest as pharmaceutical and can thus be regarded as a high-value compound. 
At Celignis, an available protocol for the isolation and purification of betulin was taken and improved as an alternative method for betulin valorisation from birch bark. The protocol was specifically targeted to be less complicated and using more environmentally benign solvents for the purification. Results show that the isolation and purification of betulin is technically feasible as well as the byproducts betulinic acid and lupeol which also have interesting pharmaceutical properties. Further steps are taken to explore the possibilities to protect the generated IP.