Skip to Main Content
U.S. Forest Service
Caring for the land and serving people

United States Department of Agriculture

Home > Search > Publication Information

  1. Share via EmailShare on FacebookShare on LinkedInShare on Twitter
    Dislike this pubLike this pub
    Author(s): Alan W. RudieRichard ReinerNancy Ross-Sutherland; William Kenealy
    Date: 2007
    Source: Proceedings, TAPPI engineering, pulping and environmental conference, 2007 October 21-23, Jacksonville, FL. Atlanta, GA: TAPPI Press, 2007: [37] pages.
    Publication Series: Miscellaneous Publication
    PDF: Download Publication  (198.36 KB)


    Acid pretreatment of wood provides significant energy savings during refining but reduces the brightness of the pulp. Acid treatments also extract carbohydrates from wood. Addition of an acid pretreatment process to a thermomechanical pulping process therefore offers an opportunity to reduce refining energy cost and provide a secondary product from a fermentation ethanol plant. A process being investigated by BioPulping International and the Forest Products Laboratory involves pretreatment with oxalic acid or diethyl oxalate and offers 25% or more reduction in specific refiner energy consumption, with a minor sacrifice in brightness. This treatment also results in extraction of approximately 6% of the wood mass. Similarly, research during the late 1970s on sulfonated chemimechanical pulping at low pH determined that bisulfite reduced specific refining energy, maintained brightness, and released carbohydrates. The similarity in behavior of these two pretreatments suggests a common mechanism that is the subject of this study. Our hypothesis is that both acids provide optimal conditions, either buffering at pH 2 or mildly reducing conditions, for pretreating wood. To test this hypothesis, a series of spruce and aspen veneer samples were pretreated with sodium bisulfate, sulfurous acid, and oxalic acid. These three acids can provide buffering near pH 2 and a range of redox potential. The wood chip brightness of the sodium bisulfate and oxalic acid experiments were similar but at a given yield sulfurous acid seems to preserve brightness better than does either bisulfate or oxalic acid. The redox activity does not seem to affect results.

    Publication Notes

    • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
    • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.


    Rudie, Alan W.; Reiner, Richard; Ross Sutherland, Nancy J.; Kenealy, William. 2007. Acid prehydrolysis of wood. Proceedings of TAPPI engineering, pulping and environmental conference, 2007 October 21-23, Jacksonville, FL. Atlanta, GA: TAPPI Press, 2007: [37] pages.


    Sulfurous acid, spruce, sodium sulfate, wood chips, oxalic acid, wood-pulp industry, energy conservation, wood-pulp, aspen, alcohol, fermentation, pulping, carbohydrates, sodium sulphate, diethyl oxalate, chips, pulping, Populus, pulp and paper processes, thermomechanical pulping, brightness, acid prehydrolysis, ethanol, pretreatment

    Related Search

    XML: View XML
Show More
Show Fewer
Jump to Top of Page