The Potential of Birch Wood and Plywood Waste as a Feedstock for Production of Organosolv Lignin

This study shows that plywood production waste is a viable feedstock for generating lignin and bioethanol using an organosolv-based fractionation process. The recovered lignin can be further utilized in Lignin-Phenol-Formaldehyde resin synthesis, enabling its reintegration into new plywood products. Thus, the proposed novel process concept supports both waste recycling and high-value product generation within circular bioeconomy framework. The potential of this approach was evaluated by comparing the organosolv fractionation performance of plywood waste with that of birch and by analyzing the resulting pulp and lignin quality. Only minor differences were observed between the two feedstocks, and these did not hinder process efficiency. Both materials yielded high-quality lignin and competitive bioethanol outputs. Extensive lignin characterization revealed that analytical pyrolysis provides more reliable qualitative information than conventional methods due to the presence of pseudolignin. No significant differences were detected between lignins from birch and plywood residues, confirming that plywood waste is a promising raw material for further lignin-based applications.