Applied Biochemistry and Biotechnology

, Volume 77, Issue 1–3, pp 133–142

Dilute acid hydrolysis of softwoods

Scientific note
  • Quang A. Nguyen
  • Melvin P. Tucker
  • Fred A. Keller
  • Delicia A. Beaty
  • Kevin M. Connors
  • Fannie P. Eddy
Article

Abstract

Whole tree chips obtained from softwood forest thinnings were converted to ethanol via a two-stage dilute acid hydrolysis followed by yeast fermentation. The chips were first impregnated with dilute sulfuric acid, then pretreated in a steam explosion reactor to hydrolyze, more than 90% of the hemicellulose and approx 10% of the cellulose. The hydrolysate was filtered and washed with water to recover the sugars. The washed fibers were then subjected to a second acid im pregnation and hydrolysis to hydrolyze as much as 45% of the reamining cellulose. The liquors from both hydrolysates were combined and fermented to ethanol by a Saccharomyces cerevisiae yeast that had been adapted to the inhibitors. Based on available hexose sugars, ethanol yields varied from 74 to 89% of theoretical. Oligosaccharide contents higher than about 10% of the total available sugar appear to have a negative impact on ethanol yield.

Index Entries

Biomass softwood ethanol pretreatment bioconversion acid hydrolysis 

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Copyright information

© Humana Press Inc. 1999

Authors and Affiliations

  • Quang A. Nguyen
    • 1
  • Melvin P. Tucker
    • 1
  • Fred A. Keller
    • 1
  • Delicia A. Beaty
    • 1
  • Kevin M. Connors
    • 1
  • Fannie P. Eddy
    • 1
  1. 1.National Renewable Energy LaboratoryGolden

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