Applied Biochemistry and Biotechnology

, Volume 124, Issue 1–3, pp 1133–1141 | Cite as

Pretreatment of switchgrass by ammonia fiber explosion (AFEX)

  • Hasan Alizadeh
  • Farzaneh Teymouri
  • Thomas I. Gilbert
  • Bruce E. DaleEmail author


The effects of ammonia fiber explosion (AFEX) pretreatment of switch grass using its major process variables are reported. The optimal pretreatment conditions for switchgrass were found to be near 100°C reactor temperature, and ammonia loading of 1:1 kg of ammonia: kg of dry matter with 80% moisture content (dry weight basis [dwb]) at 5 min residence time. Hydrolysis results of AFEX-treated and untreated samples showed 93% vs 16% glucan conversion, respectively. The ethanol yield of optimized AFEX-treated switchgrass was measured to be about 0.2 g ethanol/g dry biomass, which is 2.5 times more than that of the untreated sample.

Index Entries

Ammonia fiber explosion (AFEX) switchgrass enzymatic hydrolysis simultaneous saccharification and fermentation 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Moser, L. E. and Vogel, K. P. (1995), in An introduction to grassland agriculture. Forages, R. F. Barnes, D. A. Miller, and C. J. Nelson (eds.), Vol. 1, Iowa State Univ. Press, Ames. pp. 409–420.Google Scholar
  2. 2.
    Research brief #51 (2001), Switchgrass production for biomass. Center for Integrated Agricultural System (CIAS), Scholar
  3. 3.
    McLaughlin, S., et al. (1999), in Perspectives on new crops and new uses. J. Janick (ed.), ASHS Press, Alexandria, VA. pp. 282–299.Google Scholar
  4. 4.
    Walter, A. (2000), Industrial uses of biomass energy Rosillo-Calle, F., Bajay S. V., and Rothman H., eds., Taylor & Francis, pp. 200–253.Google Scholar
  5. 5.
    Holtzapple, M. T., Jun, J., Ashok, G., Patibanadala, S. L., and Dale, B. E. (1991), Appl. Biochem. Bioethanol. 28/29, 59–74.CrossRefGoogle Scholar
  6. 6.
    Dale, B. E., Weaver, J., and Byers, F. M. (1999), Extrusion processing for ammonia fiber explosion (AFEX), Appl. Biochem. Biotechnol. 7–79, 1–11.Google Scholar
  7. 7.
    Dale, B. E. (1999), Biobased industrial products: bioprocess engineering when cost really counts, Biotechnol. Prog. 15, 775–776.CrossRefGoogle Scholar
  8. 8.
    Moniruzzaman, M., Dien, B. S., Ferrer, B., et al. (1997), Ethanol production from AFEX pretreated corn fiber by Recombinant Bacteria, Biotechnol. Lett. 18, 985–990.CrossRefGoogle Scholar
  9. 9.
    Teymouri F., Alizadeh H., Laureano-Pérez L., and Dale, B. Ammonia fiber explosion (AFEX) treatment of corn stover, Appl. Biochem. Biotechnol. 113–116, 951–963.Google Scholar
  10. 10.
    Wang, P. Y., Bolker, H. I., and Purves, C. B. (1967), Uranic Acid Ester Groups in Some Softwoods and Hardwoods, Tappi 50, 123–124.Google Scholar
  11. 11.
    O’Conner, J. J. (1972), Ammonia Explosion Pulping-New Fiber Separation Process, Tappi 55, 353–358.Google Scholar

Copyright information

© Humana Press Inc. 2005

Authors and Affiliations

  • Hasan Alizadeh
    • 1
  • Farzaneh Teymouri
    • 1
  • Thomas I. Gilbert
    • 1
  • Bruce E. Dale
    • 1
    Email author
  1. 1.Department of Chemical Engineering and Materials ScienceMichigan State UniversityEast Lansing

Personalised recommendations