Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

Formic-acid-induced depolymerization of oxidized lignin to aromatics

Nature volume 515, pages 249–252 (2014)Cite this article

Subjects

Abstract

Lignin is a heterogeneous aromatic biopolymer that accounts for nearly 30% of the organic carbon on Earth1 and is one of the few renewable sources of aromatic chemicals2. As the most recalcitrant of the three components of lignocellulosic biomass (cellulose, hemicellulose and lignin)3, lignin has been treated as a waste product in the pulp and paper industry, where it is burned to supply energy and recover pulping chemicals in the operation of paper mills4. Extraction of higher value from lignin is increasingly recognized as being crucial to the economic viability of integrated biorefineries5,6. Depolymerization is an important starting point for many lignin valorization strategies, because it could generate valuable aromatic chemicals and/or provide a source of low-molecular-mass feedstocks suitable for downstream processing7. Commercial precedents show that certain types of lignin (lignosulphonates) may be converted into vanillin and other marketable products8,9, but new technologies are needed to enhance the lignin value chain. The complex, irregular structure of lignin complicates chemical conversion efforts, and known depolymerization methods typically afford ill-defined products in low yields (that is, less than 10–20wt%)2,10,11. Here we describe a method for the depolymerization of oxidized lignin under mild conditions in aqueous formic acid that results in more than 60wt% yield of low-molecular-mass aromatics. We present the discovery of this facile C–O cleavage method, its application to aspen lignin depolymerization, and mechanistic insights into the reaction. The broader implications of these results for lignin conversion and biomass refining are also considered.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Lignin structure and strategies for depolymerization.
Figure 2: C–O cleavage of lignin model compounds with formic acid.
Figure 3: Depolymerization of aspen lignin with formic acid.
Figure 4: Mechanistic study of C–O cleavage in 2.

Similar content being viewed by others

References

  1. Ralph, J., Brunow, G. & Boerjan, W. Lignins. eLShttp://dx.doi.org/10.1002/9780470015902.a0020104 (2007)

  2. Zakzeski, J., Bruijnincx, P. C. A., Jongerius, A. L. & Weckhuysen, B. M. The catalytic valorization of lignin for the production of renewable chemicals. Chem. Rev. 110, 3552–3599 (2010)

    Article  CAS  Google Scholar 

  3. Sanderson, K. Lignocellulose: a chewy problem. Nature 474, S12–S14 (2011)

    Article  CAS  Google Scholar 

  4. Lin, S. Y. & Lin, I. S. in Ullmann’s Encyclopedia of Industrial Chemistry 5th edn (eds Elvers, B., Hawkins, S., Schulz, G. ) Vol. A15 305–315 (VCH, 1985)

    Google Scholar 

  5. Tuck, C. O., Pérez, E., Horváth, I. T., Sheldon, R. A. & Poliakoff, M. Valorization of biomass: deriving more value from waste. Science 337, 695–699 (2012)

    Article  CAS  ADS  Google Scholar 

  6. Holladay, J. E., Bozell, J. J., White, J. F. & Johnson, D. Top Value-added Chemicals from Biomass Vol. 2 http://www1.eere.energy.gov/bioenergy/pdfs/pnnl-16983.pdf (United States Department of Energy, 2007)

    Google Scholar 

  7. Ragauskas, A. J. et al. Lignin valorization: improving lignin processing in the biorefinery. Science 344, 1246843 (2014)

    Article  Google Scholar 

  8. Hocking, M. B. Vanillin: synthetic flavoring from spent sulfite liquor. J. Chem. Educ. 74, 1055–1059 (1997)

    Article  CAS  Google Scholar 

  9. Business Areas. Borregaard http://www.borregaard.com/Business-Areas (20 June 2014)

  10. Pandey, M. P. & Kim, C. S. Lignin depolymerization and conversion: a review of thermochemical methods. Chem. Eng. Technol. 34, 29–41 (2011)

    Article  CAS  Google Scholar 

  11. Wang, H., Tucker, M. & Ji, Y. Recent development in chemical depolymerization of lignin: a review. J. Appl. Chem 2013, 1–9 (2013)

    Article  Google Scholar 

  12. Gierer, J. & Norén, I. Oxidative pretreatment of pine wood to facilitate delignification during kraft pulping. Holzforschung 36, 123–130 (1982)

    Article  CAS  Google Scholar 

  13. Ljunggren, S. & Olsson, A. The specificity in oxidation of some lignin and carbohydrate models and pine wood shavings with permanganate and pyridinum dichloromate before the kraft pulping process. Holzforschung 38, 91–99 (1984)

    Article  CAS  Google Scholar 

  14. Rahimi, A., Azarpira, A., Kim, H., Ralph, J. & Stahl, S. S. Chemoselective metal-free aerobic oxidation in lignin. J. Am. Chem. Soc. 135, 6415–6418 (2013)

    Article  CAS  Google Scholar 

  15. Crestini, C. & D’Auria, M. Singlet oxygen in the photodegradation of lignin models. Tetrahedron 53, 7877–7888 (1997)

    Article  CAS  Google Scholar 

  16. Fukagawa, N. & Ishizu, A. Photoreaction of phenacyl aryl ether type lignols. J. Wood Chem. Technol. 11, 263–289 (1991)

    Article  CAS  Google Scholar 

  17. Argyropoulos, D. S. & Sun, Y. Photochemically induced solid-state degradation, condensation, and rearrangement reactions in lignin model compounds and milled wood lignin. Photochem. Photobiol. 64, 510–517 (1996)

    Article  CAS  Google Scholar 

  18. Vanucci, C., De Violet, P. F., Bouas-Laurent, H. & Castellan, A. Photodegradation of lignin: a photophysical and photochemical study of a non-phenolic α-carbonyl β-O-4 lignin model dimer, 3,4-dimethoxy-α-(2′-methoxyphenoxy) acetophenone. J. Photochem. Photobiol. Chem. 41, 251–265 (1988)

    Article  CAS  Google Scholar 

  19. Nguyen, J. D., Matsuura, B. S. & Stephenson, C. R. J. A photochemical strategy for lignin degradation at room temperature. J. Am. Chem. Soc. 136, 1218–1221 (2014)

    Article  CAS  Google Scholar 

  20. Collinson, S. R. & Thielemans, W. The catalytic oxidation of biomass to new materials focusing on starch, cellulose and lignin. Coord. Chem. Rev. 254, 1854–1870 (2010)

    Article  CAS  Google Scholar 

  21. Chatel, G. & Rogers, R. D. Oxidation of lignin using ionic liquids—an innovative strategy to produce renewable chemicals. ACS Sustainable Chem. Eng. 2, 322–339 (2014)

    Article  CAS  Google Scholar 

  22. Chang, H., Cowling, E. B. & Brown, W. Comparative studies on cellulolytic enzyme lignin and milled wood lignin of sweetgum and spruce. Holzforschung 29, 153–159 (1975)

    Article  CAS  Google Scholar 

  23. Ralph, J. & Landucci, L. L. in Lignin and Lignans; Advances in Chemistry (eds Heitner, C., Dimmel, D. R. & Schmidt, J. A. ) 137–234 (CRC Press, 2010)

    Book  Google Scholar 

  24. Fouad, F. M. & Farrell, P. G. Primary and secondary kinetic isotope effects in E2 elimination reactions. Tetrahedr. Lett. 19, 4735–4738 (1978)

    Article  Google Scholar 

  25. Xu, W., Miller, S. J., Agrawal, P. K. & Jones, C. W. Depolymerization and hydrodeoxygenation of switchgrass lignin with formic acid. ChemSusChem 5, 667–675 (2012)

    Article  CAS  Google Scholar 

  26. Toledano, A. et al. Fractionation of organosolv lignin from olive tree clippings and its valorization to simple phenolic compounds. ChemSusChem 6, 529–536 (2013)

    Article  CAS  Google Scholar 

  27. Bauer, K., Garber, D. & Surburg, H. in Ullmann’s Encyclopedia of Industrial Chemistry 5th edn (eds Elvers, B., Rounsaville, J. F. & Schulz, G. ) Vol. A11 199–200 (VCH, 1985)

    Google Scholar 

  28. Bjørsvik, H.-R. & Liguori, L. Organic processes to pharmaceutical chemicals based on fine chemicals from lignosulfonates. Org. Process Res. Dev. 6, 279–290 (2002)

    Article  Google Scholar 

  29. Martínez, Á. T. et al. Monolignol acylation and lignin structure in some nonwoody plants: a 2D NMR study. Phytochemistry 69, 2831–2843 (2008)

    Article  Google Scholar 

  30. Luterbacher, J. S. et al. Nonenzymatic sugar production from biomass using biomass-derived γ-valerolactone. Science 343, 277–280 (2014)

    Article  CAS  ADS  Google Scholar 

Download references

Acknowledgements

We thank J. Ralph for numerous helpful discussions, H. Kim and A. Azarpira for assistance with the purification and NMR characterization of aspen lignin, and S. Chakraborty for assistance with gel-permeation chromatographic analysis of lignin samples. Financial support for this project was provided by the Great Lakes Bioenergy Research Center (Department of Energy Biological and Environmental Research Office of Science DE-FC02-07ER64494). The NMR facility was partly supported by the National Science Foundation (CHE-9208463) and the National Institutes of Health (S10 RR08389).

Author information

Authors and Affiliations

  1. Department of Chemistry, University of Wisconsin–Madison, 1101 University Avenue, Madison, 53706, Wisconsin, USA

    Alireza Rahimi, Arne Ulbrich, Joshua J. Coon & Shannon S. Stahl

  2. Department of Biomolecular Chemistry, University of Wisconsin–Madison, Madison, 53706, Wisconsin, USA

    Joshua J. Coon

Authors
  1. Alireza Rahimi
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Arne Ulbrich
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Joshua J. Coon
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Shannon S. Stahl
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

A.R. and S.S.S. conceived the idea for the lignin depolymerisation. A.R. performed the chemical reactions of lignin and lignin model compounds, including NMR spectroscopic characterization of the products. A.U. and J.J.C. designed the analytical approach to characterize the lignin depolymerization products. A.U. performed LC/MS analysis. A.R. and S.S.S. wrote the manuscript in consultation with A.U. and J.J.C.

Corresponding author

Correspondence to Shannon S. Stahl.

Ethics declarations

Competing interests

A patent application based on the results reported here has been submitted.

Supplementary information

Supplementary Information

This file contains Supplementary Text and Data, Supplementary Figures 1-6 and Supplementary Tables 1-2. (PDF 3606 kb)

PowerPoint slides

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Rahimi, A., Ulbrich, A., Coon, J. et al. Formic-acid-induced depolymerization of oxidized lignin to aromatics. Nature 515, 249–252 (2014). https://doi.org/10.1038/nature13867

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nature13867

This article is cited by

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing