Abstract
Lignin is a major byproduct in the biomass-to-ethanol process. The lignin produced from acid treatment of biomass has characteristics suitable for further conversion to organic chemicals. It is free of contaminants and has a relatively low molecular weight. In this study, catalytic oxidative conversion of the acid-soluble lignin precipitated from acid hydrolysates of hardwood was investigated. The process is based on aqueous alkaline oxidation of lignin with dissolved O2 in the presence of Fe3+ and Cu2+ catalysts at moderate reaction temperatures (160–180°C). Aromatic aldehydes, ketones, and organic acids are found to be the primary products identifiable on extraction with ether. The combined weight yield of the total ether extractable products is about 20–25% of the initial lignin. The yield of the aldehydes (vanillin + syringaldehyde) is in the vicinity of 15% with an additional 3 to 4% of aromatic ketones. The yields of aldehydes plus ketones observed in this work far exceeded those obtainable from the conventional alkaline air oxidation of spent sulfite liquors. This article also provides comprehensive batch reaction data on conversion and product distribution.
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References
Torget, R. W., Nagel, N., Jennings, E., Ibsen K., and Elander, R. (1999), 21st Symposium on Biotechnology for Fuels and Chemicals, Fort Collins, CO.
Chang, H.-M. and Allan, G. G. (1971), in Lignins Occurrence, Formation, Structure and Reactions, Sarkanen, K. V. and Ludwig, C. H., eds., Wiley-Interscience, New York, pp. 433–485.
Goheen, D. W. (1981), in Organic Chemicals from Biomass, Goldstein, I. S., ed., CRC, Boca Raton, FL, pp. 143–161.
Hocking, M. B. (1997), J. Chem. Ed. 74, 1055–1059.
Pommier, Y., Macdonald, T. L., and Madalengoitia, J. S. (1994), PCT Int. Appl. WO 94 10,175.
Cushman, M. S. and Hamel, E. (1993), PCT Int. Appl. WO 93 23,357.
Xiang, Q. and Lee, Y. Y. (2000), Appl. Biochem. Biotechnol. 84/86, 153–162.
Overend, R. P. and Chornet, E. (1990), Can. J. Physiol. 68(9), 1105–1111.
Abatzoglou, N., Chornet, E., Belkacemi, K., and Overend, R. P. (1992), Chem. Eng. Sci. 47(5) 1109–1122.
Gierer, J. and Imsgard, F. (1977), Sven. Papperstidn. 80(16), 510–518.
Fargues, C., Mathias, A., Silva, J. and Rodrigues, A. (1996), Chem. Eng. Technol. 19, 127–136.
Sultanov, V. S. and Wallis F. A. (1991), J. Wood Chem. Technol. 11(3), 291–305.
Wu, G., Heitz, M., and Chornet, E. (1994), Ind. Eng. Chem. Res. 33, 718–723.
Wu, G. and Heitz, M. (1995), J. Wood. Chem. Technol. 15(2), 189–202.
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Xiang, Q., Lee, Y.Y. Production of oxychemicals from precipitated hardwood lignin. Appl Biochem Biotechnol 91, 71–80 (2001). https://doi.org/10.1385/ABAB:91-93:1-9:71
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DOI: https://doi.org/10.1385/ABAB:91-93:1-9:71