Search for dissertations about: "Reduction chemical"

Showing result 1 - 5 of 923 swedish dissertations containing the words Reduction chemical.

  2. 1. Metal-exchanged zeolites for NH3-SCR applications - Activity and Deactivation studies

    Author : Soran Shwan; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; modeling; NOX.; Hydrothermal; Chemical; Kinetic; Copper; Deactivation; Iron; Zeolite; Nitrogen oxides; NH3; Ammonia; Catalyst; NSR; Emissions; Poisoning; Ageing; NH3-SCR;

    Abstract : Emissions of nitrogen oxides (NOX) formed during the burning process in internal combustion engines is a major contributor to global air pollutions. One effective way to reduce NOX in lean environments, i.e. oxygen excess is selective catalytic reduction with ammonia (NH3-SCR). READ MORE

  4. 2. Behavior of iron-based oxygen carriers at deep reduction states

    Author : Victor Purnomo; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; oxygen carrier; fuel conversion; chemical looping; physical performance; deep reduction; reactivity; iron oxides;

    Abstract : Oxygen carriers have an important role as bed materials in both common circulating fluidized bed combustion unit (also known as oxygen-carrier-aided combustion, OCAC) and in various chemical looping processes. Contrary to conventional bed materials, e.g., sand, oxygen carriers are capable of transferring both oxygen and heat. READ MORE

  5. 3. Lean NOx reduction by alternative fuels - with focus on catalysts for dimethyl ether

    Author : Sara U Erkfeldt; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; biofuel; In2O3; lean NOx reduction; alumina; Cu-ZSM-5; Ga2O3; DME; hydrocarbon-SCR; alternative fuel; NOx storage; B2O3; Ag Al2O3;

    Abstract : There is an increased demand for diesel engines running on non-fossil fuels such as dimethyl ether (DME), biodiesel and synthetic diesel. DME is a promising alternative fuel with potential for high energy efficiency and low CO2 emissions. However, during all high temperature combustion NOx is formed, which may require exhaust aftertreatment. READ MORE

  6. 4. Transient In Situ Studies on Supported Catalysts: CO2 Methanation and Methane Oxidation

    Author : Felix Hemmingsson; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; CH4 oxidation; Catalytic methanation; Hydrogenation; Sabatier reaction; CO2 reduction; HE-XRD; XAS; DRIFTS; AP-XPS; Heterogeneous catalysis; In situ spectroscopy;

    Abstract : This dissertation aims to increase the understanding of important steps in the catalytic CO2 hydrogenation and total methane oxidation reactions over supported noble metal catalysts. A general theme is the role of the metal oxide support for the catalytic reactions. READ MORE

  7. 5. Deactivation of SCR catalysts - Impact of sulfur and the use of biofuels

    Author : Johanna Englund; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Cu-SSZ-13; Cu-CHA; Catalyst deactivation; Activity test; DeNOx; Sulfur; NOx reduction; NH3-SCR; FAME; Emission control; HVO; Vanadia; Biofuel;

    Abstract : In a near future, limits on CO2 emissions from vehicles will be introduced, which requires development of more fuel-efficient engines and most likely a transition towards the use of more biofuels. With the implementation of biofuels several issues could arise, one being the lack of fuel standards for these new type of fuels, leading to higher concentrations of catalyst poisons compared to conventional fossil fuels. READ MORE