Sökning: "Lignin"

Visar resultat 1 - 5 av 281 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; Chalmers University of Technology; []
    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

    Författare :Maxim Galkin; Joseph Samec; Rafael Luque; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; AGRICULTURAL SCIENCES; LANTBRUKSVETENSKAPER; NATURVETENSKAP; LANTBRUKSVETENSKAPER; NATURAL SCIENCES; 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. Fractionation of woody biomass : lignin and suberin in focus

    Författare :Ivan Kumaniaev; Joseph Samec; Claudia Crestini; Stockholms universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; lignocellulose; lignin; suberin; biomass; palladium; catalysis; flow chemistry; organisk kemi; Organic Chemistry;

    Sammanfattning : This thesis is dedicated to the research of fractionation and valorization of different types of woody biomass. In the first part, oak (Quercus suber) and birch (Betula pendula) barks are considered. Bark is the outer layer of wood and is treated as waste in the current wood processing technologies. LÄS MER

  4. 4. Lignin Conversion to Value-Added Small-Molecule Chemicals : Towards Integrated Forest Biorefineries

    Författare :Omar Y. Abdelaziz; Institutionen för kemiteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; aromatic monomers; biorefinery; catalysis; kraft lignin; lignin depolymerization; lignin valorization; microbial conversion; renewable chemicals; techno-economic analysis;

    Sammanfattning : Lignin is the most abundant aromatic biopolymer on Earth and has significant potential as a feedstock for industrial use. Due to its intrinsic heterogeneity and recalcitrance, lignin has been regarded as a low-value side-product in the pulp and paper industry and in second-generation biorefineries. LÄS MER

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

    Författare :Raghu Deshpande; Ulf Germgård; Pedro Fardim; Karlstads universitet; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; 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