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

Highlights1. Existing circular economy (CE) monitors, mainly, assess the extent to which resources are looped back in the economy and seem less apt for assessing the circularity of biological cycles. 2. Characteristics of biological cycles, that distinguish them from technical cycles, are their renewability, potential use in cascading, closing the biological nutrient loop, and the environmental impact of biotic resources depletion, land-use and biogenic carbon flows. 3. These characteristics need to be added to CE monitoring criteria, to ensure the sustainable and circular use of natural resources.

The environmental and economic challenges currently faced by the wax market may be addressed by the use of sustainable bio-based alternatives. Hereto, ketonization of vegetable oils and animal fats is...

Birch bark was converted to a hydrocarbon biofuel through solubilization and hydrotreatment. The procedure implements a recyclable, salt- and metal-free solvent system and has been evaluated by Life-Cycle Assessment.

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