Sökning: "Hexenuronic acid"

Visar resultat 11 - 15 av 21 avhandlingar innehållade orden Hexenuronic acid.

  1. 11. On the bleachability of alkaline pulps. The influence of residual lignin structure

    Författare :Waleed Wafa Al-Dajani; KTH; []
    Nyckelord :B-O-4; bleachability; hexenuronic acid; hydrogen peroxide; hydrosulfide ion; hydroxyl ion; ionic strength; residual lignin.;

    Sammanfattning : .... LÄS MER

  3. 12. Aspects of extended impregnation kraft cooking for high-yield pulping of hardwood

    Författare :Helena Wedin; Mikael E. Lindström; Martin Ragnar; Jorge L. Colodette; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Yield; pulp; kraft cook; carbohydrate; xylan; oxygen delignification; Hexenuronic acid; kappa number;

    Sammanfattning : The long-term trend regarding wood is an increase in price. Because wood contributes to a large part of production costs, the efficient utilisation of wood is greatly desired to reduce production costs for kraft pulp producers. During the 1990s, the development of improved modified kraft cooking began, which led to higher yields. LÄS MER

  4. 13. On the Course of Kraft Cooking - The impact of ionic strength

    Författare :Binh Dang; Chalmers tekniska högskola; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; molecular weight distribution.; hexenuronic acids; carbohydrate removal; delignification; sodium ion concentration; lignin; ionic strength; xylan; flow-through kraft cooking; kinetics;

    Sammanfattning : Kraft pulping is the dominant process currently used to produce chemical pulps, and has been applied for more than 130 years. A large number of studies have been conducted to gain a better understanding of the delignification kinetics as well as the reactions of the wood components being dissolved during the cooking process. LÄS MER

  5. 14. Xylan reactions in kraft cooking and their influence on paper sheet properties

    Författare :Sverker Danielsson; Mikael E. Lindström; Stefan Backa; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Cellulose and paper engineering; Cellulosa- och pappersteknik;

    Sammanfattning : Xylan is the main hemicellulose in birch, eucalyptus, and most other hardwood species. During kraft pulping a series of chemical reactions and physical processes involving xylan take place. LÄS MER

  7. 15. Carbohydrate degradation and dissolution during Kraft cooking : Modelling of kinetic results

    Författare :Dan Johansson; Ulf Germgård; Pedro Fardim; Karlstads universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Kraft cooking; softwood; hardwood; cellulose; xylan; glucomannan; degradation; dissolution; Chemical engineering; Kemiteknik; Chemical Engineering; Kemiteknik;

    Sammanfattning : Chemical pulp fibres from wood are commonly used in products associated with packaging as well as with printing and writing. The prevalent way of liberating fibres is by subjecting wood chips to Kraft cooking. This process has a history of almost 130 years and should be both well described and well established. LÄS MER