Sökning: "lignin"

Visar resultat 1 - 5 av 273 avhandlingar innehållade ordet lignin.

  1. 1. Viscosity and boiling point elevation of black liquor from the lignin extraction process and the modification of extracted lignin

    Författare :Ali Seid Moosavifar; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Boiling point elevation; viscosity; Lignin precipitation; Black liquor; black liquor properties; evaporation characteristic; combustion of lignin; Lignin; calcium addition to lignin; alkalisation of black liquor; lignin modification; lignin fuel;

    Sammanfattning : .... LÄS MER

  2. 2. Palladium-catalyzed lignin valorization Towards a lignin-based biorefinery

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Maxim Galkin; Joseph Samec; Rafael Luque; [2015]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; Lignin; Heterogeneous Catalysis; Palladium; Biomass; Depolymerization; Reduction; Oxidation; Biorefinery; Transfer Hydrogenolysis; Organic Chemistry; Organisk kemi;

    Sammanfattning : The work described in this thesis focuses on the cleavage of the β-O-4′ bond, which is the most abundant interunit linkage in the lignin polymer.In the first part, three methods based on palladium catalysis have been developed and their applicability has been verified using lignin model compounds. LÄS MER

  3. 3. Lignin Extraction from Black Liquor - Properties of the Liquors and Sulphur Content in the Lignin

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Ali Seid Moosavifar; [2008]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; heat-treatment; lignin precipitation; boiling point elevation; lignin; alkalisation; biofuel; properties; viscosity; Black liquor; combustion of lignin; lignin modification; viscosity correlations.;

    Sammanfattning : Kraft lignin isolated by precipitation can be considered as being a valuable renewable source of energy and material. Removing lignin from black liquor is also advantageous as it decreases the load on the recovery boiler, which is usually the limiting factor in the production of kraft pulp. LÄS MER

  4. 4. Towards a pure kraft lignin

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Rufus Ziesig; [2014]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; LignoBoost; black liquor; lignin; impurities; purification; carbohydrate; inorganics; precipitation;

    Sammanfattning : The most widely used production method for paper pulp in the world is kraft pulping. In chemical pulping the polymer, lignin, which binds the wood fibres together, is partly depolymerized. This allows the wood fibres to be separated from each other. LÄS MER

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

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Raghu Deshpande; Ulf Germgård; Pedro Fardim; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER