Search for dissertations about: "deactivation"

Showing result 6 - 10 of 172 swedish dissertations containing the word deactivation.

  2. 6. 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. 7. Deactivation of cobalt and nickel catalysts in Fischer-Tropsch synthesis and methanation

    Author : Javier Barrientos; Magali Boutonnet; Claude Mirodatos; KTH; []
    Keywords : 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. 8. Catalyst Deactivation by Coke Formation in Acetylene Hydrogenation

    Author : Staffan Asplund; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; preparative liquid chromatography; gross error detection; acetylene hydrogenation; coke deposition; coke formation; catalyst deactivation;

    Abstract : Several aspects of catalyst deactivation have been studied with reference toselective acetylene hydrogenation, a reaction used industrially to purify ethylene from unwanted acetylene. A mathematical model has been developed for an industrial packed-bed reactor, employing a supported Pd catalyst. READ MORE

  6. 9. Deactivation of diesel oxidation catalysts

    Author : Jonas Andersson; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Accelerated aging: Diesel exhaust: Oxidation catalyst: Sulfur deactivation: Phosphorous poisoning: CO oxidation: Pt dispersion: Al2O3: Sintering: TEM: XPS;

    Abstract : To meet the demand for heavy- and light-duty diesel vehicles on expansive markets while complying with current and future emission standards, it is necessary to reinsure the long-livety of the applied exhaust aftertreatment technology. Loss of catalytic performance may be associated with environmental as well as economical consequences. READ MORE

  7. 10. Deactivation of emission control catalysts for heavy-duty vehicles : Impact of biofuel and lube oil-derived contaminants

    Author : Sandra Dahlin; Lars Pettersson; Isabella Nova; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NH3-SCR; Cu-SSZ-13; V2O5-WO3 TiO2; catalyst deactivation; diesel oxidation catalyst; sulfur; phosphorus; biodiesel; heavy-duty; emission control; regeneration; alkali metals; NH3-SCR; Cu-SSZ-13; V2O5-WO3 TiO2; katalysatordeaktivering; dieseloxidationskatalysator; svavel; fosfor; biodiesel; tunga dieselmotorer; avgasrening; regenerering; alkalimetaller; Chemical Engineering; Kemiteknik;

    Abstract : Catalytic emission control is used to reduce the negative impact of pollutants from diesel exhausts on our health and on the environment. For a heavy-duty truck, such a system consists of a diesel oxidation catalyst (DOC), a diesel particulate filter (DPF), a selective catalytic reduction (SCR) catalyst, and an ammonia slip catalyst (ASC). READ MORE