Sökning: "Residual phase lignin"

Hittade 5 avhandlingar innehållade orden Residual phase lignin.

1. 1. 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. 2. On the Interrelation Between Kraft Cooking Conditions and Pulp Composition

   Författare :Catrin Gustavsson; Mikael E. Lindström; Jorge Colodette; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Delignification; Kraft pulping; Residual phase lignin; Hydroxide; Hydrogen sulphide ion; Ionic strength; Temperature; Bleachability; Hexenuronic acid; Carbohydrates; Cellulose and paper engineering; Cellulosa- och pappersteknik;

   Sammanfattning : 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. LÄS MER

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

   Författare :Ragnar Sjödahl; Mikael E. Lindström; Hasan Jameel; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Delignification; Dissolved wood components; Black liquor; Defibration point; Cellulose and paper engineering; Cellulosa- och pappersteknik;

   Sammanfattning : 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. LÄS MER

5. 4. Oxidation of Kraft Pulp Fibres - Hydrogen Peroxide Oxidation under Acidic Conditions and its Influence on the Properties of Pulp

   Författare :Axel Martinsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : An increase in the use of bio-based products, combined with a decrease in the use of fossil-based products, is important for fulfilling the demands of a growing population in a sustainable manner. Moreover, reducing the usage of single-use plastics is vital in combating the plastic pollution that is afflicting our environment. LÄS MER

7. 5. Numerical modelling of biomass thermochemical conversion and potassium release

   Författare :Seyed Morteza Mousavi; Strömningsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Numerical modelling; particle model; bed model; CFD simulation; biomass; pyrolysis; ; combustion; gasification; potassium release; alkali;

   Sammanfattning : The use of biomass as a renewable source of energy has been increasing over the past few decades, and biomass is regarded as a promising replacement for fossil fuels. Thermochemical conversion of biomass is a common approach for biomass utilization with a relatively short conversion time. LÄS MER