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Comparative material balances around pretreatment technologies for the conversion of switchgrass to soluble sugars
BioSource Technology (2011)
  • Rebecca G. Ong, Michigan Technological University
  • Venkatesh Balan, Michigan State University
  • Bruce E. Dale, Michigan State University
  • Venkata Ramesh Pallapolu, Auburn University
  • Y. Y. Lee, Michigan State University
  • Youngmi Kim, Purdue University
  • Nathan S. Mousier, Purdue University
  • Michael R. Ladisch, Purdue University
  • Mark T. Holtzapple, Texas A&M University
  • Matthew Falls, Texas A&M University
  • Rocio Sierra-Ramirez, Universidad de Los Andes - Colombia
  • Jian Shi, University of California at Riverside
  • Mirvat A. Ebrik, University of California at Riverside
  • Tim Redmond, University of California at Riverside
  • Bin Yang, University of California at Riverside
  • Charles E. Wyman, University of California at Riverside
  • Bryon S. Donohoe, National Renewable Energy Laboratory
  • Todd B. Vinzant, National Renewable Energy Laboratory
  • Richard T. Elander, National Renewable Energy Laboratory
  • Bonnie Hames, Ceres, Inc.
  • Steve Thomas, Ceres, Inc.
  • Ryan E. Warner, Genencor
For this project, six chemical pretreatments were compared for the Consortium for Applied Fundamentals and Innovation (CAFI): ammonia fiber expansion (AFEX), dilute sulfuric acid (DA), lime, liquid hot water (LHW), soaking in aqueous ammonia (SAA), and sulfur dioxide (SO2). For each pretreatment, a material balance was analyzed around the pretreatment, optional post-washing step, and enzymatic hydrolysis of Dacotah switchgrass.

All pretreatments + enzymatic hydrolysis solubilized over two-thirds of the available glucan and xylan. Lime, post-washed LHW, and SO2 achieved >83% total glucose yields. Lime, post-washed AFEX, and DA achieved >83% total xylose yields. Alkaline pretreatments, except AFEX, solubilized the most lignin and a portion of the xylan as xylo-oligomers. As pretreatment pH decreased, total solubilized xylan and released monomeric xylose increased. Low temperature-long time or high temperature-short time pretreatments are necessary for high glucose release from late-harvest Dacotah switchgrass but high temperatures may cause xylose degradation.
  • cellulosic ethanol,
  • enzymatic hydrolysis,
  • material balance,
  • pretreatment,
  • switchgrass
Publication Date
December, 2011
Publisher Statement
© 2011 Elsevier Ltd. All rights reserved.
Citation Information
Rebecca G. Ong, Venkatesh Balan, Bruce E. Dale, Venkata Ramesh Pallapolu, et al.. "Comparative material balances around pretreatment technologies for the conversion of switchgrass to soluble sugars" BioSource Technology Vol. 102 Iss. 24 (2011) p. 11063 - 11071 ISSN: 0960-8524
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