Search for dissertations about: "Bleaching efficiency"

Showing result 1 - 5 of 26 swedish dissertations containing the words Bleaching efficiency.

  2. 1. On the Process Development of an ECF Light Bleaching Sequence for the Production of High Quality Softwood Kraft Pulp and Low AOX Formation

    Author : Sara Starrsjö; Juha Fiskari; Mikael Lindström; Olena Sevastyanova; Maria Boman; Peter Sandström; Mittuniversitetet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Chemical Engineering; Natural Science; Chemical Pulping; Softwood; Kraft Pulp; Bleaching; ECF light bleaching; Chlorine Dioxide; AOX formation; Delignification; Bleachability;

    Abstract : The aim of this work is to contribute to the process development of the ECF light bleaching sequence Q(OP)D(PO) by providing a better understanding of the bleaching of softwood kraft pulp. There are few published studies on this type of sequence, and more knowledge is needed on how to reduce environmental impact, improve cost-effectiveness and ensure a high pulp quality. READ MORE

  4. 2. Xylan degradation by the thermophilic bacterium Rhodothermus marinus. Characterization and function of a thermostable xylanase

    Author : Eva Nordberg Karlsson; Bioteknik; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fed-batch cultivation; kraft pulp; bleaching; glycosyl hydrolase family 10; recombinant xylanase; polysaccharide binding domain; Biotechnology; Bioteknik;

    Abstract : A gene encoding a multidomain xylanase from the thermophilic bacterium Rhodothermus marinus has been cloned, sequenced and produced in Escherichia coli . The gene product was found to be a 109 kDa protein consisting of five domains. READ MORE

  5. 3. ATMP Process : Improved Energy Efficiency in TMP Refining Utilizing Selective Wood Disintegration and Targeted Application of Chemicals

    Author : Dmitri Gorski; Per Engstrand; Jan Hill; Lars Johansson; Mittuniversitetet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ATMP; TMP; Hydrogen Peroxide; Magnesium Hydroxide; Mechanical Pre-Treatment; Fibre Characterisation; Refiner Bleaching; SC Paper; Newsprint; Cellulose and paper engineering; Cellulosa- och pappersteknik;

    Abstract : This thesis is focused on the novel wood chip refining process called AdvancedThermomechanical Pulp (ATMP) refining. ATMP consists of mechanical pretreatmentof chips in Impressafiner and Fiberizer prior to first stage refining atincreased intensity. READ MORE

  6. 4. The Impact of Dissolved Matter on Fiberline Processes

    Author : Caroline Wilke; Ulf Germgård; Niclas Andersson; Juha Fiskari; Karlstads universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; 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;

    Abstract : 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. READ MORE

  7. 5. Fibre surface properties of kraft pulp : The influence of wood raw material, bleaching and storage

    Author : Gerd Wäne; Ulf Germgård; Pedro Fardim; Karlstads universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Chemical Engineering; Kemiteknik;

    Abstract : The aim of this thesis was to study the fibre surface properties of Birch (Betula ssp.), Eucalyptus (E. urograndis and E. globulus) and Spruce (Picea Abies) pulps bleached using two different methods: ECF (Elementary Chlorine Free) and TCF (Totally Chlorine Free). READ MORE