Search for dissertations about: "Kemiteknik"

Showing result 1 - 5 of 1136 swedish dissertations containing the word Kemiteknik.

  1. 1. The initial phase of the sodium bisulfite pulping of softwood dissolving pulp

    Author : Raghu Deshpande; Ulf Germgård; Martin Ragnar; Karlstads universitet; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Activation energy; bisulfite pulping; cellulose; delignification; extractives; glucomannan; hemicelluloses; lignin; pine; spruce; thiosulfate; total SO2; xylan; Chemical Engineering; Kemiteknik;

    Abstract : The sulfite pulping process is today practised in only a small number of pulp mills around the globe and the number of sulfite mills that use sodium as the base (cation) is less than five. However, due to the increasing interest in the wood based biorefinery concept, the benefits of sulfite pulping and especially the sodium based variety, has recently gained a lot of interest. READ MORE

  2. 2. On Gas Contaminants, and Bipolar Plates in Proton Exchange Membrane Fuel Cells

    Author : Yasna Acevedo Gomez; Carina Lagergren; Göran Lindbergh; Rakel Wreland Lindström; Qinfeng Li; KTH; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; PEM fuel cell; contaminants; ammonia; nitrogen dioxide; degradation; recovery; bipolar plates; electroplating; Ni-Mo; Ni-Mo-P; internal contact resistance; PEM bränslecell; föroreningar; ammoniak; kvävedioxid; degradering; återhämtning; bipolära plattor; elektroplätering; Ni-Mo; Ni-Mo-P; interna kontaktmotståndet; Chemical Engineering; Kemiteknik;

    Abstract : The proton exchange membrane (PEM) fuel cell is an electrochemical device that converts chemical energy into electrical energy through two electrocatalytic reactions. The most common catalyst used is platinum on carbon (Pt/C), which has shown the best performance in the fuel cell until now. READ MORE

  3. 3. Recovery of Rare Earth Elements from an Apatite Concentrate

    Author : Mahmood Alemrajabi; Kerstin Forsberg; Åke C. Rasmuson; Koen Binnemans; KTH; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Rare earth elements; precipitation; nitrophosphate process; hollow fiber supported liquid membrane extraction; Chemical Engineering; Kemiteknik;

    Abstract : Rare earth elements (REE) are a group of 17 elements including lanthanides, yttrium and scandium; which are found in a variety of classes of minerals worldwide. The criticality of the application, lack of high grade and economically feasible REE resources and a monopolistic supply situation has raised significant attention in recovery of these metals from low grade ores and waste materials. READ MORE

  4. 4. Deactivation of cobalt and nickel catalysts in Fischer-Tropsch synthesis and methanation

    Author : Javier Barrientos; Magali Boutonnet; Claude Mirodatos; KTH; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; cobalt; nickel; Fischer-Tropsch synthesis; methanation; deactivation; carbonyl; sintering; carbon fomation. sulfur; poisoning; Chemical Engineering; Kemiteknik;

    Abstract :             A potential route for converting different carbon sources (coal, natural gas and biomass) into synthetic fuels is the transformation of these raw materials into synthesis gas (CO and H2), followed by a catalytic step which converts this gas into the desired fuels. The present thesis has focused on two catalytic steps: Fischer-Tropsch synthesis (FTS) and methanation. READ MORE

  5. 5. Interactions between battery and power electronics in an electric vehicle drivetrain

    Author : Alexander Bessman; Göran Lindbergh; Pontus Svens; Oskar Wallmark; Torbjörn Thiringer; KTH; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Chemical Engineering; Kemiteknik; Electrical Engineering; Elektro- och systemteknik;

    Abstract : The electric machine and power electronics in electric and hybrid electric vehicles inevitably cause AC harmonics on the vehicle's DC-link. These harmonics can be partially filtered out by large capacitors, which today are overdimensioned in order to protect the vehicle's battery pack. READ MORE