Sökning: "Hydroxide ion"

Visar resultat 1 - 5 av 34 avhandlingar innehållade orden Hydroxide ion.

  1. 1. Some aspects on TCF-bleachability of softwood alkaline pulps

    Detta är en avhandling från Stockholm : KTH

    Författare :Karin Sjöström; KTH.; [1999]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Bleachability; chlorine-free bleaching; softwoods; kraft pulps; alkaline sulfite pulps; oxygen; hydrogen peroxide; ozone; hydrogen sulfide ion; hydroxide ion; temperature; sodium ion.; TECHNOLOGY Chemical engineering Chemical process and manufacturing engineering Cellulose and paper engineering; TEKNIKVETENSKAP Kemiteknik Kemisk process- och produktionsteknik Cellulosa- och pappersteknik;

    Sammanfattning : The bleachability of softwood oxygen delignified pulps has been studied, i.e. the ease (requirement of bleaching chemicals) with which the pulps can be brightened to a target brightness in totally chlorine free (TCF) bleaching stages, including hydrogen peroxide, ozone and chelating agent stages. LÄS MER

  2. 2. Some factors affecting the amount of residual phase lignin during kraft pulping

    Detta är en avhandling från Stockholm : KTH

    Författare :Mikael E. Lindström; KTH.; [1997]
    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; TECHNOLOGY Chemical engineering Chemical process and manufacturing engineering Cellulose and paper engineering; TEKNIKVETENSKAP Kemiteknik Kemisk process- och produktionsteknik 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. 3. On the Interrelation Between Kraft Cooking Conditions and Pulp Composition

    Detta är en avhandling från Stockholm : KTH

    Författare :Catrin Gustavsson; KTH.; [2006]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Delignification; Kraft pulping; Residual phase lignin; Hydroxide; Hydrogen sulphide ion; Ionic strength; Temperature; Bleachability; Hexenuronic acid; Carbohydrates; TECHNOLOGY Chemical engineering Chemical process and manufacturing engineering Cellulose and paper engineering; TEKNIKVETENSKAP Kemiteknik Kemisk process- och produktionsteknik 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. 4. Poly(phenylene oxide)s functionalized with cationic side chains: design, synthesis and properties as anion exchange membranes

    Detta är en avhandling från Centre for Analysis and Synthesis

    Författare :Hai-Son Dang; Lunds universitet.; Lund University.; [2017-07-12]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; anion exchange membranes; Anion exchange membrane fuel cells; poly phenylene oxide s; hydroxide conductivity; alkaline stability; lithiation; Menshutkin reaction;

    Sammanfattning : Anion exchange membrane fuel cells (AEMFCs) are considered as one of the most important next-generation energy conversion technologies. AEMFCs convert chemical energy into useful electrical energy and have great potential forachieving high conversion efficiencies. LÄS MER

  5. 5. Synthesis and applications of low silica zeolites from Bolivian clay and diatomaceous earth

    Detta är en avhandling från Luleå : Luleå University of Technology

    Författare :Javier Gustavo Garcia Mendoza; Luleå tekniska universitet.; [2017]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Zeolites; Synthesis; clay; diatomite; adsorption; ion exchange; Chemical Technology; Kemisk teknologi;

    Sammanfattning : The aim of the present work was to develop synthesis routes to produce synthetic zeolites with industrial attractiveness from non-expensive Bolivian raw materials, such as clays and diatomite. In particular, the work was focused on the synthesis of low-silica zeolites with the LTA and FAU structures. LÄS MER