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): Qingzhi Ma; Kolby Hirth; Huamin Zhai; J.Y. Zhu
    Date: 2020
    Source: ACS Sustainable Chemistry & Engineering. 8(24): 9046-9057.
    Publication Series: Scientific Journal (JRNL)
    Station: Forest Products Laboratory
    PDF: Download Publication  (5.0 MB)


    This study evaluated the bleachability of wood fibers from acid hydrotropic fractionation (AHF) of birch using ptoluenesulfonic acid (p-TsOH) at low temperatures below 90 °C. The wood fibers had varying amounts of lignin after AHF under different conditions using both batch and flow-through configurations. The extent of lignin reprecipitation in batch mode was evaluated by extended washing with p-TsOH. 2D 13C−1H nuclear magnetic resonance (NMR) spectroscopy indicated that residual lignin on fibers from batch reaction was significantly more condensed than that from flow-through under equivalent conditions. Furthermore, condensation substantially affected oxidative bleaching by reducing the reactivity of the residual lignin. Even a little variation in the extent of lignin condensation showed a marked effect on sample bleachability. Specifically, oxygen bleaching at 110 °C removed 79% of residue lignin from a batch fractionated fiber sample with 7% β-O-4 aryl ether linkage and resulted in 55% ISO fiber brightness. The same oxygen bleaching removed 87% of residue lignin from a flow-through fractionated fiber sample with almost the same lignin content but with a higher β-O-4 of 16%, or lower degree of lignin condensation, and higher brightness of 59% ISO. The 4% increase in brightness with the same loading of bleaching chemical translates to significant cost reduction. Furthermore, a brightness of 70% or more can be achieved with single stage peroxide bleaching for the flow-through AHF fibers

    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.


    Ma, Qingzhi; Hirth, Kolby; Zhai, Huamin; Zhu, J.Y. 2020. Highly bleachable wood fibers containing less condensed lignin from acid hydrotropic fractionation (AHF). ACS Sustainable Chemistry & Engineering. 8(24): 9046-9057.


    Google Scholar


    acid hydroytrope fractionation, fiber bleaching, lignin condensation, NMR lignin analyses

    Related Search

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