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Showing result 1 - 5 of 58 swedish dissertations matching the above criteria.

2. 1. Hardwood delignification

   Author : Linus Kron; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Precipitated lignin; Black liquor; Hardwood; Kraft delignification; Mass transport;

   Abstract : For the necessary transition into a sustainable and circular society, lignocellulosic resources are set to play a crucial role in replacing fossil-based materials. In the valorisation of lignocellulosic materials, kraft pulping is one of the key processes. READ MORE

4. 2. Pulp strength enhancement by oxygen delignification

   Author : Claudia Esteves; Elisabet Brännvall; Olena Sevastyanova; Sören Östlund; Christine Chirat; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fiber charge; morphology; oxygen delignification; swellability; tensile properties; dragegenskaper; fiberladdningar; morfologi; svällningsförmåga; syrgasdelignifiering; Chemical Engineering; Kemiteknik;

   Abstract : Oxygen delignification is widely used in the pulp and paper industry as a part of delignification process between the kraft cook and bleaching. However, its potential has not been fully utilized. READ MORE

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

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

   Abstract : 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. READ MORE

6. 4. On the Course of Kraft Cooking - The impact of ionic strength

   Author : Binh Dang; Chalmers tekniska högskola; []
   Keywords : LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; molecular weight distribution.; hexenuronic acids; carbohydrate removal; delignification; sodium ion concentration; lignin; ionic strength; xylan; flow-through kraft cooking; kinetics;

   Abstract : Kraft pulping is the dominant process currently used to produce chemical pulps, and has been applied for more than 130 years. A large number of studies have been conducted to gain a better understanding of the delignification kinetics as well as the reactions of the wood components being dissolved during the cooking process. READ MORE

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

   Author : Raghu Deshpande; Ulf Germgård; Pedro Fardim; Karlstads universitet; []
   Keywords : 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;

   Abstract : 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. READ MORE