Search for dissertations about: "E Cook"

Showing result 1 - 5 of 16 swedish dissertations containing the words E Cook.

  2. 1. Aspects of extended impregnation kraft cooking for high-yield pulping of hardwood

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

    Abstract : 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. READ MORE

  4. 2. Some factors affecting the amount of residual phase lignin during kraft pulping

    Author : Mikael E. Lindström; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Deligniflcation; Residual phase lignin; Hydrogensulfide ion; Hydroxide ion; Polysulfides; Ionic strength; Temperature; Lignin; Kraftpulping; Selectivity; viscosity; Kappa number; chemical degradation; Disproportionation; Cellulose and paper engineering; Cellulosa- och pappersteknik;

    Abstract : The amount of lignin which needs to be removed according to the slow residual delignification phase in kraft pulping, i e residual phase lignin, has been studied as a function of the process conditions. The variebles studied were the concentrations of hydroxide ions, hydrogensulfide ions, sodium ions (ionic strength) and temperature. READ MORE

  5. 3. On the Interrelation Between Kraft Cooking Conditions and Pulp Composition

    Author : Catrin Gustavsson; Mikael E. Lindström; Jorge Colodette; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Delignification; Kraft pulping; Residual phase lignin; Hydroxide; Hydrogen sulphide ion; Ionic strength; Temperature; Bleachability; Hexenuronic acid; Carbohydrates; Cellulose and paper engineering; Cellulosa- och pappersteknik;

    Abstract : In the early 1990’s, a lot of work was focused on extending the kraft cook to a low lignin content (low kappa number). The driving force was the need to further reduce the environmental impact of the bleaching, as less delignification work would be needed there. READ MORE

  6. 4. Some aspects on the effects of dissolved wood components in kraft pulping

    Author : Ragnar Sjödahl; Mikael E. Lindström; Hasan Jameel; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Delignification; Dissolved wood components; Black liquor; Defibration point; Cellulose and paper engineering; Cellulosa- och pappersteknik;

    Abstract : During kraft cooking a significant part of the wood material, especially lignin and hemicelluloses, is degraded and dissolved in the cooking liquor, rendering a broad range of degradation products with different molecular mass and functional groups. The main part of this thesis has been devoted to clarify the role of these dissolved wood components (DWC) during kraft cooking. READ MORE

  7. 5. Extended impregnation kraft cooking of softwood : Effects on reject, yield, pulping uniformity, and physical properties

    Author : Katarina Karlström; Mikael E. Lindström; Elisabet Brännvall; Kristofer Gamstedt; Anna Jacobs; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; high kappa number pulp; extended impregnation; softwood; spruce; picea abies; pine; pinus sylvestris; uniform delignification; kappa number distribution; reject; yield; tensile index; tensile stiffness index; SCT; starch multilayers; mechano-sorptive creep; hygroexpansion; dimensional stability; eucalypt; birch; acacia; Cellulose and paper engineering; Cellulosa- och pappersteknik;

    Abstract : Converting wood into paper is a complex process involving many different stages, one of which is pulping. Pulping involves liberating the wood fibres from each other, which can be done either chemically or mechanically. READ MORE