Sökning: "hexenuronic acid"

Visar resultat 1 - 5 av 21 avhandlingar innehållade orden hexenuronic acid.

  1. 1. Kraft pulping - Reaction kinetics of lignin and hexenuronic acid in softwood

    Författare :Johannes Bogren; Chalmers University of Technology; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; DWC; Reaction kinetics; LCC; Hexenuronic acid; Mass transfer resistance; Ionic strength; Softwood; Delignification; Kraft pulping;

    Sammanfattning : .... LÄS MER

  2. 2. On the importance of oxidizable structures in bleached kraft pulps

    Författare :Olena Sevastyanova; Göran Gellerstedt; Colodette Jorge; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; bleached pulps; betula; eucalyptus; 5-formyl-2furancarboxylic acid; 2-furancarboxylic acid; hexenuronic acid; kappa number; kraft pulps; oxidation equivalents; Cellulose and paper engineering; Cellulosa- och pappersteknik;

    Sammanfattning : After cooking, kraft pulps always contain not only residual lignin but also significant amounts of hexenuronic acid and other non-lignin structures oxidizable by permanganate under the standard kappa number determination conditions. These here referred to as false lignin. LÄS MER

  3. 3. Xylan Reactions in Kraft Cooking : Process and Product Considerations

    Författare :Sverker Danielsson; Mikael Lindström; Richard Gustafson; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Xylan; Kraft cooking; Paper strength; Sheet density; Methylglucuronic acid; Hexenuronic acid; Cellulose and paper engineering; Cellulosa- och pappersteknik;

    Sammanfattning : Xylan is the main hemicellulose in birch, eucalyptus, and most other hardwood species. During kraft pulping a series of chemical reactions and physical processes involving xylan takes place. LÄS MER

  4. 4. New Tools for Analysis of Wood and Pulp Components - Application of MALDI-TOF Mass Spectroscopy and Capillary Zone Electrophoresis

    Författare :Anna Jacobs; KTH; []
    Nyckelord :Capillary zone electrophoresis; carbohydrate composition; degree of acetylation; degree of polymerization; enzymatic hydrolysis; hardwood; hemicellulose; hexenuronic acid; lignin; MALDI-TOF mass spectroscopy; molar mass; molar mass distribution; olig;

    Sammanfattning : In the present thesis, capillary zone electrophoresis (CZE),matrix-assisted laser desorption/ionization time-of-flight massspectroscopy (MALDI-MS) and size-exclusion chromatography incombination with off-line MALDI-MS (SEC/MALDI-MS) have beenapplied successfully to the analysis of wood and pulpcomponents.The carbohydrate compositions of pulp and holocellulosesamples, as well as of isolated hemicellulose preparations,were determined employing enzymatic hydrolysis and subsequentanalysis of the saccharides released by CZE. LÄS MER

  5. 5. The Impact of Dissolved Matter on Fiberline Processes

    Författare :Caroline Wilke; Ulf Germgård; Niclas Andersson; Juha Fiskari; Karlstads universitet; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; Bleach plant control; Carbonate; Carryover; Chlorine dioxide bleaching; COD; Dissolved lignin; Dissolved matter; Fiberline control; Filtrate; Hexenuronic acid; Hydrogen peroxide bleaching; Kappa number; Oxygen delignification; Wash loss; Chemical Engineering; Kemiteknik;

    Sammanfattning : The impact of dissolved matter on the performance of four fiberline process stages was investigated: oxygen delignification, hot acid treatment, chlorine dioxide bleaching, and hydrogen peroxide reinforced alkaline extraction. In particular the impact on delignification due to dissolved lignin was studied. LÄS MER