Search for dissertations about: "Delignification"

Showing result 1 - 5 of 45 swedish dissertations containing the word Delignification.

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

    University dissertation from Stockholm : KTH

    Author : Ragnar Sjödahl; KTH.; [2006]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Delignification; Dissolved wood components; Black liquor; Defibration point; TECHNOLOGY Chemical engineering Chemical process and manufacturing engineering Cellulose and paper engineering; TEKNIKVETENSKAP Kemiteknik Kemisk process- och produktionsteknik 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

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

    University dissertation from Chalmers University of Technology

    Author : Binh Dang; Chalmers tekniska högskola.; Chalmers University of Technology.; [2017]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; kinetics; xylan; lignin; flow-through kraft cooking; carbohydrate removal; delignification; ionic strength; hexenuronic acids; molecular weight distribution.; sodium ion concentration;

    Abstract : 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. READ MORE

  3. 3. The initial phase of sodium sulfite pulping of softwood A comparison of different pulping options

    University dissertation from Karlstad : Karlstads universitet

    Author : Raghu Deshpande; Karlstads universitet.; [2016]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Activation energy; acid sulfite pulping; bisulfite pulping; cellulose; delignification; dissolving pulp; extractives; glucomannan; hemicelluloses; lignin; lignin condensation; lignin carbohydrate complexes; pine; spruce; thiosulfate; total SO2; xylan; Chemical Engineering; Kemiteknik;

    Abstract : Single stage and two-stage sodium sulfite cooking were carried out on either spruce, pine or pure pine heartwood chips to investigate the influence of several process parameters on the initial phase of such a cook down to about 60 % pulp yield. The cooking experiments were carried out in the laboratory with either a lab-prepared or a mill-prepared cooking acid and the temperature and time were varied. READ MORE

  4. 4. The initial phase of the sodium bisulfite pulping of softwood dissolving pulp

    University dissertation from Karlstad : Karlstads universitet

    Author : Raghu Deshpande; Karlstads universitet.; [2015]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Activation energy; bisulfite pulping; cellulose; delignification; extractives; glucomannan; hemicelluloses; lignin; pine; spruce; thiosulfate; total SO2; xylan; Chemical Engineering; Kemiteknik;

    Abstract : The sulfite pulping process is today practised in only a small number of pulp mills around the globe and the number of sulfite mills that use sodium as the base (cation) is less than five. However, due to the increasing interest in the wood based biorefinery concept, the benefits of sulfite pulping and especially the sodium based variety, has recently gained a lot of interest. READ MORE

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

    University dissertation from Stockholm : KTH

    Author : Catrin Gustavsson; KTH.; [2006]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Delignification; Kraft pulping; Residual phase lignin; Hydroxide; Hydrogen sulphide ion; Ionic strength; Temperature; Bleachability; Hexenuronic acid; Carbohydrates; TECHNOLOGY Chemical engineering Chemical process and manufacturing engineering Cellulose and paper engineering; TEKNIKVETENSKAP Kemiteknik Kemisk process- och produktionsteknik 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