A sustainable wood biorefinery for low–carbon footprint chemicals production

Abstract

Profitability and sustainability of future biorefineries are dependent on efficient feedstock utilization. It is essential to valorize lignin when using wood. We have developed an integrated biorefinery that converts 78 wt.% of birch into xylochemicals. Reductive catalytic fractionation of wood gives a carbohydrate pulp amenable to bioethanol production and a lignin oil. After extraction of lignin oil, the crude, unseparated mixture of phenolic monomers is catalytically funneled into 20 wt.% of phenol and 9 wt.% of propylene (on lignin basis) by gas-phase hydroprocessing/dealkylation, whereas the residual phenolic oligomers (30 wt.%) are used in printing ink as replacements for controversial para-nonylphenol. Techno-economic analysis predicts an economically competitive production, and life-cycle assessment estimates a lower CO ₂ footprint relative to fossil-based production.