Ammonia Recycled Percolation as a Complementary Pretreatment to the Dilute-Acid Process

  • Zhang Wen Wu
  • Y. Y. Lee
Chapter
Part of the Applied Biochemistry and Biotechnology book series (ABAB, volume 63-65)

Abstract

A two-stage dilute-acid percolation (DA) was investigated as a pretreatment method for switchgrass. With use of extremely low acid (0.078 wt% sulfuric acid) under moderate temperature (145–170°C), hemicellulose in switchgrass was completely solubilized showing no sugar decomposition. The treated switchgrass contained about 70% glucan and 30% lignin. The high lignin content in the treated feedstock raises a concern that it may cause a high enzyme consumption because of irreversible adsorption of cellulase enzymes to lignin. This problem may be amplified in the SSF operation since it is usually run in fed-batch mode and the residual lignin is accumulated. The DA pretreatment was, therefore, combined with the ammonia recycled percolation (ARP) process that has been proven to be effective in delignification. The combined pretreatment essentially fractionated the switchgrass into three major components. The treated feedstock contained about 90% glucan and 10% lignin. The digestibility of these samples was consistently higher that that of DA treated samples. Further study on the interaction of cellulase with xylan and that with lignin has shown that the enzymatic hydrolysis of cellulose is inhibited by lignin as well as xylan. The external xylan was found to be a noncompetitive inhibitor to cellulose hydrolysis. The cellulase used in this study was proven to have the xylanase activity.

Index Entries

Pretreatment delignification dilute-acid cellulase adsorption xylan hydrolysis 

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References

  1. 1.
    Chernaglazov, V. M., Ermolova, O. V., and Klyosv, A. A. (1988), Enzyme Microb. Technol. 10, 503–507.CrossRefGoogle Scholar
  2. 2.
    Tanka, M., Fukui, M., and Mastsuno, R. (1988), Biotechnol. Bioeng. 32, 897–902.CrossRefGoogle Scholar
  3. 3.
    Lee, D., Yu, A. H. C., and Saddler, J. N. (1995), Biotechnol. Bioeng. 45, 328–336.CrossRefGoogle Scholar
  4. 4.
    Castellanos, O. F., Sinitsyn, A. P., and Vlasenko, E. Y. (1995), Bioresouce Technol. 52, 109–117.CrossRefGoogle Scholar
  5. 5.
    Giard, D. J. and Converse, A. O. (1993), Appl. Biochem. Biotechnol. 39/40, 521–533.CrossRefGoogle Scholar
  6. 6.
    Ooshima, H., Burns, D. S., and Converse, A. O. (1990), Biotechnol. Bioeng. 36, 446–452.CrossRefGoogle Scholar
  7. 7.
    Ngugen, Q. A., and Saddler, J. N. (1991), Bioresearch and Technol. 35, 275–282.CrossRefGoogle Scholar
  8. 8.
    Stone, J., Scallan, A., Donefer, E., and Ahlgren, E. (1969), Adv. Chem. Seri. 95, 219–241.CrossRefGoogle Scholar
  9. 9.
    Ramos, L. P., Breuil, C., and Saddler, J. N. (1992), Appl. Biochem. Biotechnol. 34/35, 37–48.CrossRefGoogle Scholar
  10. 10.
    Yoon, H. H., Wu, Z. W., Kim, S. B., and Lee, Y. Y. (1995), Appl. Biochem. Biotechnol. 51/52, 5–19.CrossRefGoogle Scholar
  11. 11.
    Iyer, P., Wu, Z. W., and Lee, Y. Y. (1996), Appl. Biochem. Biotechnol. 57/58,121–132.CrossRefGoogle Scholar
  12. 12.
    Lee, Y. Y., Lin, C. M., and Chambers, R. P. (1979), Biotechnol. Bioeng. Symp. 8, 75–88.Google Scholar
  13. 13.
    Torget, R., Walter, P., Himmel, M., and Grohmann, K. (1991), Appl. Biochem. Biotechnol. 28/29,75–86.CrossRefGoogle Scholar
  14. 14.
    Chen, R., Torget, R., and Lee, Y. Y. (1996), Appl. Biochem. Biotechnol. 57/58,133–146.CrossRefGoogle Scholar
  15. 15.
    Torget, R., Hatzis, C., Hayward, T. K., Hsu, T., and Philippidis, G. P. (1996) Appl. Biochem. Biotechnol. 57/58, (in press).Google Scholar
  16. 16.
    Sjöström, E. (1993), Wood Chemistry: Fundamentals and Applications, 2nd edition, Academic Press, New York, NY.Google Scholar
  17. 17.
    Grohmann, K., Mitchell, D. J., Himmel, M. E., Dale, B. E., and Schroeder, H. A. (1989), Appl. Biochem. Biotechnol. 20/21, 45–61.CrossRefGoogle Scholar
  18. 18.
    Kong, F., Engler, C. R., and Soltes, E. J. (1992), Appl. Biochem. Biotechnol. 34/35, 23–35.CrossRefGoogle Scholar
  19. 19.
    Wilson, D. B. (1992), Critical Review in Biotechnology,12(1/2), 45–63.CrossRefGoogle Scholar
  20. 20.
    Matsushita ,O., Russell, J. B., and Wilson, D. B. (1990), J. Bacteriol.,17, 3620–3630.Google Scholar
  21. 21.
    Yagüe, E., Béguin, P., and Aubert, J.-P. (1990), Gene 89, 61–67.CrossRefGoogle Scholar
  22. 22.
    Johnston, D. B. and Sheomaker, S. P. (1996), Assessment of Enzyme Kinetics Using Purified Endoglucanases and Insoluble Substrates, presented at 18th Symposium of Biotechnology for Chemicals and Fuel, Gatlinburg, TN.Google Scholar
  23. 23.
    Kim, B. J., Lee, Y. Y., and Torget, R. (1994), Appl. Biochem. Biotechnol. 45/46,113–129.CrossRefGoogle Scholar

Copyright information

© Humana Press Inc. 1997

Authors and Affiliations

  • Zhang Wen Wu
    • 1
  • Y. Y. Lee
    • 1
  1. 1.Chemical Engineering DepartmentAuburn UniversityAuburnUSA

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