Search for dissertations about: "na2co3"

Showing result 1 - 5 of 17 swedish dissertations containing the word na2co3.

  2. 1. Model for activity coefficients and solubilities of Na2CO3 and Na2SO4 in high-temperature solutions

    Author : Marta Anna Bialik; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; scaling; Pitzer model; activity coefficient; solubility; sodium carbonate; sodium sulfate; boiling point raise; double salt; solid solution; burkeite;

    Abstract : Scaling of sodium sulfate and sodium carbonate double salts has long been recognized as a problem in the black liquor evaporation process. These salts are abundant in black liquor and often tend to precipitate on heat transfer areas, thereby significantly decreasing the heat transfer efficiency. READ MORE

  4. 2. Ceria-based nanocomposite electrolyte for low-temperature solid oxide fuel cells

    Author : Ying Ma; Mamoun Muhammed; Peter Lund; KTH; []
    Keywords : ;

    Abstract : Solid oxide fuel cells (SOFCs) have attracted much attention because of their potential of providing an efficient, environmentally benign, and fuel-flexible power generation system for both small power units and for large scale power plants. However, conventional SOFCs with yttria-stabilized zirconia (YSZ) electrolyte require high operation temperature (800-1000°C), which presents material degradation problems, as well as other technological complications and economic obstacles. READ MORE

  5. 3. Ionic Conducting Composite as Electrolyte forLow Temperature Solid Oxide Fuel Cells

    Author : Xiaodi Wang; Mamoun Muhammed; Zhu Bin; Per H Alvfors; KTH; []
    Keywords : ;

    Abstract : Solid oxide fuel cells (SOFCs) are considered as one of the most promising powergeneration technologies due to their high energy conversion efficiency, fuel flexibilityand reduced pollution. The current SOFCs with yttria-stabilized zirconia (YSZ)electrolyte require high operation temperature (800-1000 °C), which not only hinderstheir broad commercialization due to associated high cost and technologicalcomplications. READ MORE

  6. 4. Oxygen-Alkali Treatment of Kraft Pulp and Cellobiitol. Model Experiments and Applied Studies of Interest for Oxygen Bleaching

    Author : Bengt Järrehult; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; selectivity; pH-levels; copper; oxygen delignification; catalytic effects; iron; alkali; cellobiitol; magnesium; yield;

    Abstract : During oxygen delignification of kraft pulp the alkalinity has a decisive influence upon the selectivity, defined as viscosity at a given kappa number. Using 0.2% pulp consistency in order to achieve constant pH-levels a minimum selectivity was reached at pH 13, corresponding to 0.1 M NaOH. READ MORE

  7. 5. Ceria-based Nanostructured Materials for Low-Temperature Solid Oxide Fuel Cells

    Author : Ying Ma; Mamoun Muhammed; Bin Zhu; Randa Abdel-Karim; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : As one of the most efficient and environmentally benign energy conversion devices, solid oxide fuel cells (SOFC) have attracted much attention in recent years. Conventional SOFC with yttria-stabilized zirconia as electrolyte require high operation temperature (800-1000 °C), which causes significant problems like material degradation, as well as other technological complications and economic barrier for wider applications. READ MORE