Sökning: "Bleaching chemicals"

Visar resultat 1 - 5 av 18 avhandlingar innehållade orden Bleaching chemicals.

1. 1. Nanoscaled Structures in Ruthenium Dioxide Coatings

   Författare :Christine Malmgren; Håkan Olin; Joakim Bäckström; Mittuniversitetet; []
   Nyckelord :Bleaching chemicals; sodium chlorate; ruthenium dioxide; electrodes; crystallites; nanowires; microscopy; diffraction; electrocatalytic area; reduced energy consumption; NATURAL SCIENCES; NATURVETENSKAP;

   Sammanfattning : An essential ingredient in the generation of environmentally compatible pulp bleaching chemicals is sodium chlorate. Chlorate is produced in electrochemical cells, where the electrodes are the key components. In Sweden the so-called DSA !R electrodes with catalytic coatings have been produced for more than 35 years. LÄS MER

3. 2. Dietary fibre production from oat hulls

   Författare :Eva Schmitz; Bioteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Oat hulls; Dietary fibre; Chemical composition; Bleaching; Pre-treatment; Enzyme synergy;

   Sammanfattning : The current threats of climate change connected to the unsustainable consumption of fossil resources paired with an increasing world population demands the exploration of alternative raw materials for the production of food, fuel and specialty chemicals. Agricultural waste streams present suitable sources due to their availability in large quantities at low costs without competing with current food production. LÄS MER

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

   Författare :Dmitri Gorski; Per Engstrand; Jan Hill; Lars Johansson; Mittuniversitetet; []
   Nyckelord :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;

   Sammanfattning : 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. LÄS MER

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

   Författare :Caroline Wilke; Ulf Germgård; Niclas Andersson; Juha Fiskari; Karlstads universitet; []
   Nyckelord :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;

   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

7. 5. The influence of high temperature on the discoloration and degradation of carbohydrates and on hydrogen peroxide bleaching of spruce TMP

   Författare :Louise Logenius; Hans Höglund; Roland Agnemo; Mittuniversitetet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Temperature; metal ions; cellulose; glucuronic acid; UV-Vis spectroscopy; spruce; TMP; hydrogen peroxide bleaching; spectroscopy; optical properties; Chemical engineering; Kemiteknik;

   Sammanfattning : When processing wood to obtain pulp, the fibers are subjected to high temperatureat moisture levels and to the influence of metal ions. Many process developmentshave resulted in utilization of higher temperatures that induce chemical reactionsin the wood fibers. This thesis deals with some aspects of using high temperaturesin pulping processes. LÄS MER