Search for dissertations about: "Pulp viscosity"

Showing result 1 - 5 of 49 swedish dissertations containing the words Pulp viscosity.

  2. 1. Dissolving pulp : Multivariate Characterisation and Analysis of Reactivity and Spectroscopic Properties

    Author : Kristina Elg Christoffersson; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Chemistry; Dissolving pulp; reactivity; solid state 13C NMR spectroscopy; NIR spectroscopy; multivariate analysis; cellulose; viscose; Kemi; Chemistry; Kemi;

    Abstract : Various chemical properties can be used to characterise dissolving pulp. The quality of the pulp must be carefully controlled to ensure that it meets the requirements for its intended use and the further processes to be applied. READ MORE

  4. 2. Lignin Extraction from Black Liquor - Properties of the Liquors and Sulphur Content in the Lignin

    Author : Ali Seid Moosavifar; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; heat-treatment; lignin precipitation; boiling point elevation; lignin; alkalisation; biofuel; properties; viscosity; Black liquor; combustion of lignin; lignin modification; viscosity correlations.;

    Abstract : Kraft lignin isolated by precipitation can be considered as being a valuable renewable source of energy and material. Removing lignin from black liquor is also advantageous as it decreases the load on the recovery boiler, which is usually the limiting factor in the production of kraft pulp. READ MORE

  5. 3. Optimization of Pretreatment of Kraft Pulp with Nitrogen Oxides

    Author : Urban Öjteg; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Kappa number; lignins; Nitric acid; Magnesium; spent liquors; viscosity; softwood; oxygen bleaching; Nitrogen dioxide; Manganese; Oxygen; Nitrogen oxides; pretreatment; Kraft pulp;

    Abstract : Modified kraft pulp subjected to oxygen bleaching following pretreatment with 2% nitrogen dioxide for 140 min with the addition of oxygen resulted in low selectivity after subsequent oxygen bleaching. In contrast, pretreatment in the absence of oxygen removed more than 80% of the lignin after oxygen bleaching and still maintained high selectivity (kappa number less than 5 at viscosity 950 dm3/kg). READ MORE

  6. 4. Viscosity and boiling point elevation of black liquor from the lignin extraction process and the modification of extracted lignin

    Author : Ali Seid Moosavifar; Chalmers tekniska högskola; []
    Keywords : 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;

    Abstract : .... READ MORE

  7. 5. Aspects of extended impregnation kraft cooking for high-yield pulping of hardwood

    Author : Helena Wedin; Mikael E. Lindström; Martin Ragnar; Jorge L. Colodette; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Yield; pulp; kraft cook; carbohydrate; xylan; oxygen delignification; Hexenuronic acid; kappa number;

    Abstract : The long-term trend regarding wood is an increase in price. Because wood contributes to a large part of production costs, the efficient utilisation of wood is greatly desired to reduce production costs for kraft pulp producers. During the 1990s, the development of improved modified kraft cooking began, which led to higher yields. READ MORE