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Complete lignocellulose conversion with integrated catalyst recycling yielding valuable aromatics and fuels


Lignocellulose, the main component of agricultural and forestry waste, harbours tremendous potential as a renewable starting material for future biorefinery practices. However, this potential remains largely unexploited due to the lack of strategies that derive substantial value from its main constituents. Here, we present a catalytic strategy that is able to transform lignocellulose to a range of attractive products. At the centre of our approach is the flexible use of a non-precious metal catalyst in two distinct stages of a lignocellulose conversion process that enables integrated catalyst recycling through full conversion of all process residues. From the lignin, pharmaceutical and polymer building blocks are obtained. Notably, among these pathways are systematic chemo-catalytic methodologies to yield amines from lignin. The (hemi)cellulose-derived aliphatic alcohols are transformed to alkanes, achieving excellent total carbon utilization. This work will inspire the development of fully sustainable and economically viable biorefineries.

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K.B. is grateful for financial support from the European Research Council, ERC Starting Grant 2015 (CatASus) 638076. This work is part of the research programme Talent Scheme (Vidi) with project number 723.015.005 (K.B.), which is partly financed by the Netherlands Organisation for Scientific Research (NWO). Z.S. is grateful for financial support from the China Scholarship Council (grant number 201406060027). B.F. is grateful for the financial support from the Hungarian Ministry of Human Capacities (NTP-NFTÖ-17-B-0593).

Author information

K.B. conceived the idea, supervised the research and wrote the manuscript. Z.S. designed the LignoFlex process and performed all related chemical reactions. Z.S. also performed reactions related to Stage 2 and synthesized compounds 3G, 4 and 6. G.B. and A.A. contributed equally to this research and designed pathways for the functionalization of 1G and synthesized compounds 5, 7, 7S, 8, 9ae, 10, 11, 12ac, 13, 14 and 15. M.C.A.S. performed catalyst characterization. P.J.D. measured and analysed the 2D-HSQC NMR data and was involved in figure preparation. B.F. contributed to the catalytic conversion of alcohol mixture to alkanes, and designed synthetic pathways to obtain compound 6Cy. All of the authors commented on the manuscript during its preparation.

Competing interests

The authors declare no competing financial interests.

Correspondence to Katalin Barta.

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Supplementary Information

Supplementary Figures 1–93, Supplementary Tables 1–21, Supplementary Notes 1–14, Supplementary Methods, Supplementary References.

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Further reading

Fig. 1: Comprehensive catalytic strategy for complete lignocellulose conversion, which embraces the inherent complexity of the starting material.
Fig. 2: Aromatic monomers from pine lignocellulose.
Fig. 3: Catalytic and control reactions for the conversion of pine lignocellulose.
Fig. 4: Complete conversion of various lignocelluloses to aromatic and aliphatic alcohols through the flexible use of Cu20-PMO under mild (Step 1) and supercritical conditions (Step 2).
Fig. 5: Catalytic methodology for the conversion of lignocellulose-derived alcohols to alkanes.
Fig. 6: Toward fully sustainable processes.
Fig. 7: Schematic representation of the overall catalytic approach and mass balances obtained with selected pine lignocellulose.
Fig. 8: Potential applications of compounds obtained from 1G.