Sökning: "lignin"

Visar resultat 11 - 15 av 376 avhandlingar innehållade ordet lignin.

  1. 11. Some factors affecting the amount of residual phase lignin during kraft pulping

    Författare :Mikael E. Lindström; KTH; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER

  3. 12. Deepening the insights of lignin structure : Lignin-carbohydrate complex (LCC) fractionation and characterization and Kraft lignin amination

    Författare :Xueyu Du; Jiebing Li; Mikael Lindström; Jussi Sipilä; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Improvement of kraft pulping delignification efficiency and value-addition of industrial kraft lignin are two attractive topics. The proposal that delignification is deteriorated by the presence of lignin-carbohydrate complex (LCC) is still being debated. LÄS MER

  4. 13. Air-gap spinning of lignin-cellulose fibers

    Författare :Jenny Bengtsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; cellulose; carbon fibers; ionic liquid; lignin; air-gap spinning;

    Sammanfattning : Co-processing of lignin and cellulose, the two main constituents of wood, has previously been identified as a potential route for the production of inexpensive and bio-based carbon fibers. The first step in this process is to spin a precursor fiber. LÄS MER

  5. 14. Photochemical reactions of lignin: Opportunities for valorisation

    Författare :Alexander Michael Riddell; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Biomass; NMR; Lignin; Photolysis; Photochemistry; Kraft;

    Sammanfattning : Lignin is the second most abundant biopolymer after cellulose and is the largest bio-based source of aromatic compounds. However, its heterogeneous and recalcitrant structure makes it difficult to depolymerise for use in renewable chemicals production. LÄS MER

  7. 15. Hydrothermal Liquefaction of Lignin into Bio-Oil

    Författare :Huyen Nguyen Lyckeskog; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; hydrothermal conversion; aging; bio-oil; stability; subcritical water; lignin;

    Sammanfattning : Lignin, one of the three main components of lignocellulosic biomass, is the second most abundant organic polymer found on Earth. Nowadays, most of the lignin (almost 99%) produced in the Kraft pulping process is used as internal fuel. LÄS MER