Applied Biochemistry and Biotechnology

, Volume 105, Issue 1–3, pp 165–177 | Cite as

Effects of temperature and moisture on dilute-acid steam explosion pretreatment of corn stover and cellulase enzyme digestibility

  • Melvin P. Tucker
  • Kyoung H. Kim
  • Mildred M. Newman
  • Quang A. Nguyen


Corn stover is emerging as a viable feedstock for producing bioethanol from renewable resources. Dilute-acid pretreatment of corn stover can solubilize a significant portion of the hemicellulosic component and enhance the enzymatic digestibility of the remaining cellulose for fermentation into ethanol. In this study, dilute H2SO4 pretreatment of corn stover was performed in a steam explosion reactor at 160°C, 180°C, and 190°C, approx 1 wt% H2SO4, and 70-s to 840-s residence times. The combined severity (Log10 [R o ] - pH), an expression relating pH, temperature, and residence time of pretreatment, ranged from 1.8 to 2.4. Soluble xylose yields varied from 63 to 77% of theoretical from pretreatments of corn stover at 160 and 180°C. However, yields >90% of theoretical were found with dilute-acid pretreatments at 190°C. A narrower range of higher combined severities was required for pretreatment to obtain high soluble xylose yields when the moisture content of the acid-impregnated feedstock was increased from 55 to 63 wt%. Simultaneous saccharification and fermentation (SSF) of washed solids from corn stover pretreated at 190°C, using an enzyme loading of 15 filter paper units (FPU)/g of cellulose, gave ethanol yields in excess of 85%. Similar SSF ethanol yields were found using washed solid residues from 160 and 180°C pretreatments at similar combined severities but required a higher enzyme loading of approx 25 FPU/g of cellulose.

Index Entries

Pretreatment dilute-acid acid hydrolysis corn stover enzymatic hydrolysis 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Grohmann, K., Himmel, M., Rivard, C., Tucker, M., Baker, J., Torget, R., and Graboski, M. (1984), Biotechnol. Bioeng. Symp. 14, 139–157.Google Scholar
  2. 2.
    Lin, K. W., Ladisch, M. R., Voloch, M., Patterson, J. A., and Noller, C. H. (1985), Biotechnol. Bioeng. 27, 1427–1433.CrossRefGoogle Scholar
  3. 3.
    Weimer, P. J., Chou, Y. C. T., Weston, W. M., and Chase, D. B. (1986), Biotechnol. Bioeng. Symp. 17, 5–18.Google Scholar
  4. 4.
    Rolz, C., de Arriola, M. C., Valladares, J., and de Cabrera, S. (1987), Process Biochem. 22, 17–23.Google Scholar
  5. 5.
    Torget, R., Werdene, P., Himmel, M., and Grohmann, K., (1990), Appl. Biochem. Biotechnol. 24/25, 115–126.Google Scholar
  6. 6.
    Grethlein, H. E. and Converse, A. O. (1991), Bioresour.e Technol. 36, 77–82.CrossRefGoogle Scholar
  7. 7.
    Chang, V. S. and Holtzapple, M. T. (2000), Appl. Biochem. Biotech. 84–86, 5–37.CrossRefGoogle Scholar
  8. 8.
    Torget, R., Himmel, M. E., and Grohmann, K. (1992), Appl. Biochem. Biotech. 34/35, 115–123.Google Scholar
  9. 9.
    Esteghlalian, A., Hashimoto, A. G., Fenske, J. J., and Penner, M. H. (1997), Bioresour. Technol. 59, 129–136.CrossRefGoogle Scholar
  10. 10.
    Schell, D. J., Walter, P. J., and Johnson, D. K. (1992), Appl. Biochem. Biotechnol. 34/35, 659–665.Google Scholar
  11. 11.
    Torget, R., Walter, P., Himmel, M. E., and Grohmann, K. (1991), Appl. Biochem. Biotechnol. 28/29, 75–86.CrossRefGoogle Scholar
  12. 12.
    Tucker, M. P., Farmer, J. D., Keller, F. A., Schell, D. J., and Nguyen, Q. A. (1998), Appl. Biochem. Biotech. 70–72, 25–35.Google Scholar
  13. 13.
    Nguyen, Q. A., Dickow, J. H., Duff, B. W., Farmer, J. D., Glassner, D. A., and Ibsen, K. N. (1996), Bioresour. Technol. 59, 189–196.CrossRefGoogle Scholar
  14. 14.
    Chum, H. L., Johnson, D. K., Black, S. K., and Overend, R. P. (1990), Appl. Biochem. Biotechnol. 24/25, 1–14.Google Scholar
  15. 15.
    Nguyen Q. A., Tucker, M. P., Keller, F. A., and Eddy, F. P. (2000), Appl. Biochem. Biotech. 84–86, 561–570.CrossRefGoogle Scholar
  16. 16.
    Kim, K. H., Tucker, M. P., and Nguyen, Q. A. (2002), Biotechnol. Prog. 18, 489–494.CrossRefGoogle Scholar
  17. 17.
    Dowe, N. and McMillan, J. (2001), NREL Analytical Procedure, No. 008, National Renewable Energy Laboratory, Golden, CO; (Website: Scholar
  18. 18.
    Nguyen, Q. A., Tucker, M. P., Boynton, B., Keller, F. A., and Schell, D. J. (1998), Appl. Biochem. Biotechnol. 70–72, 77–87.Google Scholar
  19. 19.
    Ruiz, R. and Ehrman, T. (1996), NREL Analytical Procedure, No. 014, National Renewable Energy Laboratory, Golden, CO. (Website: Scholar
  20. 20.
    Hames, B. R., Thomas, S. R., Sluiter, A. D., Roth, C. J., and Templeton, D. W. (2003), Appl. Biochem. Biotechnol. 105–108, 5–16.CrossRefGoogle Scholar
  21. 21.
    Hamilton, F. and Leopold, B., eds. (1993), in Pulp and Paper Manufacture, vol. 3, Joint Textbook Committee of the Paper Industry of the United States and Canada, Atlanta, p. 119.Google Scholar

Copyright information

© Humana Press Inc. 2003

Authors and Affiliations

  • Melvin P. Tucker
    • 1
  • Kyoung H. Kim
    • 1
  • Mildred M. Newman
    • 1
  • Quang A. Nguyen
    • 1
  1. 1.National Renewable Energy Laboratory, Biotechnology Division for Fuels and ChemicalsNational Bioenergy CenterGolden

Personalised recommendations