Waste and Biomass Valorization

, Volume 10, Issue 1, pp 197–204 | Cite as

Mechanism Study on Depolymerization of the α-O-4 Linkage Lignin Model Compound in Supercritical Ethanol System

  • Weikun Jiang
  • Shubin WuEmail author
Original Paper


The aim of this study was to explore the conversion mechanism of α-O-4 linkage lignin dimer model compound (monobenzone) in supercritical ethanol. The decomposition processes of monobenzone were investigated at different reaction time (0–12 h), conversion temperature (250–310 °C) and initial concentrations (0.01–0.03 g/mL). The reaction mechanism and pathways were proposed based on the distribution of products, the bond dissociation energies and the free radical theory. The results showed almost complete degradation was achieved in supercritical ethanol system. A higher temperature, a longer reaction time and a higher initial concentration significantly promoted the formation of solid residue due to the condensation reactions of the degradation intermediates/products. Based on the formation mechanism of products, the conversion products were classified into three types: (1) its own fragmentation compounds, (2) condensation compounds of its intermediates and (3) the second fragmentation compounds of its intermediates. A depolymerization reaction mechanism of monobenzone that primarily involved homolytic cleavage of the Cα–O linkage was proposed. In addition, the bibenzyl were an important and unstable intermediate product, it can continue to produce many different radical species that can participate in a variety of reaction mechanisms, resulting in complex reaction pathways and products distribution, even forming higher-molecular weight solid residue.


Monobenzone α-O-4 linkage Supercritical ethanol Depolymerization 



The authors greatly acknowledge the support of the Natural Sciences Foundation of China (No.31270635 and No.31670582), and the National Basic Research Program of China (973 program, No. 2013CB228101).


  1. 1.
    Mckendry, P.: Energy production from biomass (Part 1): overview of biomass. Bioresour. Technol. 83, 37–46 (2002)CrossRefGoogle Scholar
  2. 2.
    Kang, S., Li, X., Fan, J., Chang, J.: Hydrothermal conversion of lignin: a review. Renew. Sust. Energ. Rev. 27, 546–558 (2013)CrossRefGoogle Scholar
  3. 3.
    Piskorz, J., Radlein, D., Scot, D.S.: On the mechanism of the rapid pyrolysis of cellulose. J. Anal. Appl. Pyrolysis 9, 121–137 (1986)CrossRefGoogle Scholar
  4. 4.
    Huang, J., Liu, C., Wei, S.: Thermodynamic studies of pyrolysis mechanism of cellulose monomer. Acta Chim. Sinica 67, 2081–2086 (2009)Google Scholar
  5. 5.
    Yang, H.P., Yan, R., Chen, H.P., Leed, H., Zheng, C.G.: Characteristics of hemicellulose, cellulose and lignin pyrolysis. Fuel 86, 1781–1788 (2007)CrossRefGoogle Scholar
  6. 6.
    Britt, P.F., Buchanan, A.C. III, Cooney, M.J., Martineau, D.R.: Flash vacuum pyrolysis of methoxy-substituted lignin model compounds. J. Org. Chem. 65, 1376–1389 (2000)CrossRefGoogle Scholar
  7. 7.
    Kim, K.H., Bai, X., Brown, R.C.: Pyrolysis mechanisms of methoxy substituted α-O-4 lignin dimeric model compounds and detection of free radicals using electron paramagnetic resonance analysis. J. Anal. Appl. Pyrolysis 110, 254–263 (2014)CrossRefGoogle Scholar
  8. 8.
    Akazawa, M., Kojima, Y., Kato, Y.: Effect of pyrolysis temperature on the pyrolytic degradation mechanism of β-aryl ether linkages. J. Anal. Appl. Pyrolysis 118, 164–174 (2016)CrossRefGoogle Scholar
  9. 9.
    Li, P., Chen, L., Wang, X., Yang, H., Shao, J., Chen, H.: Effects of oxygen-containing substituents on pyrolysis characteristics of β-O-4 type model compounds. J. Anal. Appl. Pyrolysis 120, 52–59 (2016)CrossRefGoogle Scholar
  10. 10.
    Parker, H.J., Chuck, C.J., Woodman, T., Jones, M.D.: Degradation of β-O-4 model lignin species by vanadium Schiff-base catalysts: Influence of catalyst structure and reaction conditions on activity and selectivity. Catal. Today 269, 40–47 (2015)CrossRefGoogle Scholar
  11. 11.
    Barbier, J., Charon, N., Dupassieux, N., Loppinet-Serani, A., Mahé, L., Ponthus, J., Courtiade, M., Ducrozet, A., Quoineaud, A.-A., Cansell, F.: Hydrothermal conversion of lignin compounds. A detailed study of fragmentation and condensation reaction pathways. Biomass Bioenergy 46, 479–491 (2012)CrossRefGoogle Scholar
  12. 12.
    Yong, T.L.K., Matsumura, Y.: Reaction kinetics of the lignin conversion in supercritical water. Ind. Eng. Chem. Res. 51, 11975–11988 (2012)CrossRefGoogle Scholar
  13. 13.
    Wu, X., Fu, J., Lu, X.: Kinetics and mechanism of hydrothermal decomposition of lignin model compounds. Ind. Eng. Chem. Res. 52, 5016–5022 (2013)CrossRefGoogle Scholar
  14. 14.
    Güvenatam, B., Heeres, E.H.J., Pidko, E.A., Hensen, E.J.M.: Decomposition of lignin model compounds by Lewis acid catalysts in water and ethanol. J. Mol. Catal. A 410, 89–99 (2015)CrossRefGoogle Scholar
  15. 15.
    Xu, C., Gilbert, A., Yang, Y.: Production of bio-crude from forestry waste by hydroliquefaction in sub-/super-critical methanol. AIChE J. 55, 807–819 (2009)CrossRefGoogle Scholar
  16. 16.
    Minami, E., Saka, S.: Comparison of the decomposition behaviors of hardwood and softwood in supercritical methanol. J. Wood Sci. 49, 73–78 (2003)CrossRefGoogle Scholar
  17. 17.
    Cheng, S., Wilks, C., Yuan, Z., Leitch, M., Xu, C.: Hydrothermal degradation of alkali lignin to bio-phenolic compounds in sub/supercritical ethanol and water/ethanol co-solvent. Polym. Degrad. Stab. 97, 839–848 (2012)CrossRefGoogle Scholar
  18. 18.
    Zhang, X.H., Zhang, Q., Wang, T.J., Ma, L.L., Yu, Y.X., Chen, L.G.: Hydrodeoxygenation of lignin-derived phenolic compounds to hydrocarbons over Ni/SiO2–ZrO2 catalysts. Bioresour. Technol. 134, 73–80 (2013)CrossRefGoogle Scholar
  19. 19.
    Zhang, X.H., Zhang, Q., Long, J.X., Xu, Y., Wang, T.J., Ma, L.L., Li Y.P.: Phenolics production through catalytic depolymerization of alkali lignin with metal chlorides. BioResources 9, 3347–3360 (2014)Google Scholar
  20. 20.
    Zhang, X.H., Zhang, Q., Wang, T.J., Li, B.S., Xu, Y., Ma, L.L.: Efficient upgrading process for production of low quality fuel from bio-oil. Fuel 179, 312–321 (2016)CrossRefGoogle Scholar
  21. 21.
    Miller, J.E., Evans, L., Littlewolf, A., Trudell, D.E.: Batch microreactor studies of lignin and lignin model compound depolymerization by bases in alcohol solvents. Fuel 78, 1363–1366 (1999)CrossRefGoogle Scholar
  22. 22.
    Molinari, V., Giordano, C., Antonietti, M., Esposito, D.: Titanium nitride-nickel nanocomposite as heterogeneous catalyst for the hydrogenolysis of aryl ethers. J. Am. Chem. Soc. 136, 1758–1761 (2014)CrossRefGoogle Scholar
  23. 23.
    Huang, X.M., Korányi, T.I., Boot, M.D., Hensen, E.J.M.: Ethanol as capping agent and formaldehyde scavenger for efficient depolymerization of lignin to aromatics. Green Chem. 17, 4941–4950 (2015)CrossRefGoogle Scholar
  24. 24.
    Chakar, F.S., Ragauskas, A.J.: Review of current and future softwood kraft lignin process chemistry. Ind. Crops Prod. 20, 131–141 (2004)CrossRefGoogle Scholar
  25. 25.
    Wang, M., Leitch, M., Xu, C.: Synthesis of phenol-formaldehyde resole resins using organosolv pine lignins. Eur. Polym. J. 45, 3380–3388 (2009)CrossRefGoogle Scholar
  26. 26.
    Deng, Y.B.: Studies of the pyrolysis behaviors of lignin model compounds. Diss. South China University of Technology (2015)Google Scholar
  27. 27.
    Yong, L.K., Yukihiko, M.: Kinetic analysis of guaiacol conversion in sub- and supercritical water. Ind. Eng. Chem. Res. 52, 1103–1111 (2013)Google Scholar

Copyright information

© Springer Science+Business Media B.V. 2017

Authors and Affiliations

  1. 1.State Key Lab of Pulp & Paper EngineeringSouth China University of TechnologyGuangzhouPeople’s Republic of China

Personalised recommendations