Applied Biochemistry and Biotechnology

, Volume 142, Issue 3, pp 276–290

Potential of Agricultural Residues and Hay for Bioethanol Production

  • Ye Chen
  • Ratna R. Sharma-Shivappa
  • Deepak Keshwani
  • Chengci Chen
Article

DOI: 10.1007/s12010-007-0026-3

Cite this article as:
Chen, Y., Sharma-Shivappa, R.R., Keshwani, D. et al. Appl Biochem Biotechnol (2007) 142: 276. doi:10.1007/s12010-007-0026-3

Abstract

Production of bioethanol from agricultural residues and hays (wheat, barley, and triticale straws, and barley, triticale, pearl millet, and sweet sorghum hays) through a series of chemical pretreatment, enzymatic hydrolysis, and fermentation processes was investigated in this study. Composition analysis suggested that the agricultural straws and hays studied contained approximately 28.62–38.58% glucan, 11.19–20.78% xylan, and 22.01–27.57% lignin, making them good candidates for bioethanol production. Chemical pretreatment with sulfuric acid or sodium hydroxide at concentrations of 0.5, 1.0, and 2.0% indicated that concentration and treatment agent play a significant role during pretreatment. After 2.0% sulfuric acid pretreatment at 121°C/15 psi for 60 min, 78.10–81.27% of the xylan in untreated feedstocks was solubilized, while 75.09–84.52% of the lignin was reduced after 2.0% sodium hydroxide pretreatment under similar conditions. Enzymatic hydrolysis of chemically pretreated (2.0% NaOH or H2SO4) solids with Celluclast 1.5 L–Novozym 188 (cellobiase) enzyme combination resulted in equal or higher glucan and xylan conversion than with Spezyme® CP- xylanase combination. The glucan and xylan conversions during hydrolysis with Celluclast 1.5 L–cellobiase at 40 FPU/g glucan were 78.09 to 100.36% and 74.03 to 84.89%, respectively. Increasing the enzyme loading from 40 to 60 FPU/g glucan did not significantly increase sugar yield. The ethanol yield after fermentation of the hydrolyzate from different feedstocks with Saccharomyces cerevisiae ranged from 0.27 to 0.34 g/g glucose or 52.00–65.82% of the theoretical maximum ethanol yield.

Keywords

Chemical pretreatmentEnzymatic hydrolysisFeedstocksFermentationGlucanLigninXylan

Copyright information

© Humana Press Inc. 2007

Authors and Affiliations

  • Ye Chen
    • 1
  • Ratna R. Sharma-Shivappa
    • 1
  • Deepak Keshwani
    • 1
  • Chengci Chen
    • 2
  1. 1.Department of Biological and Agricultural EngineeringNorth Carolina State UniversityRaleighUSA
  2. 2.Central Agricultural Research CenterMontana State UniversityMoccasinUSA