Sökning: "catalytic deactivation"

Visar resultat 21 - 25 av 74 avhandlingar innehållade orden catalytic deactivation.

  1. 21. Catalytic Converters for Automotive Exhaust Applications. Flow Dynamics, Mass Transfer and Optimization

    Författare :Fredrik Ekström; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TWC; optimization; exhaust; laboratory reactors; catalytic converter; catalysis; pressure drop; entrance effects; CFD; mass transfer; pulsations; flow distribution;

    Sammanfattning : In order to reduce emissions from vehicles powered by an internal combustion engine, an exhaust aftertreatment system is normally mounted on the engine. This aftertreatment system normally consists of one or several catalytic converters. LÄS MER

  3. 22. Deactivation of SCR catalysts - Impact of sulfur and the use of biofuels

    Författare :Johanna Englund; Chalmers tekniska högskola; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER

  4. 23. Studies of NOx Storage Catalysts - Preparation, Characterization, Sulfur Deactivation and Micro Kinetic Modelling

    Författare :JAZAER DAWODY; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; kinetic modelling; metal oxide additives; NO oxidation; Zeta potential; FTIR; SO2 oxidation; Al2O3; NOx storage and reduction catalysts; TEM; BaCO3; SEM; Pt precursors; sulfur deactivation;

    Sammanfattning : For the protection of the global environment, it is essential to decrease the emissions of CO2 which is a green house gas. Lean-burn and diesel engines offer relatively low CO2 emissions and good fuel economy. LÄS MER

  5. 24. Catalytic Processes Mediated by Metal−Organic Frameworks : Reactivity and Mechanistic Studies

    Författare :Vlad Pascanu; Belén Martín-Matute; Seth Cohen; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; organisk kemi; Organic Chemistry;

    Sammanfattning : The present thesis describes the development of heterogeneous catalytic methodologies using metal−organic frameworks (MOFs) as porous matrices for supporting transition metal catalysts. A wide spectrum of chemical reactions is covered. LÄS MER

  7. 25. Fundamental deactivation mechanisms of Fe-BEA as NH3-SCR catalyst - Experimental studies and kinetic modeling

    Författare :Soran Shwan; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Dealumination; Hydrothermal treatment; Catalyst deactivation; NH3-SCR; Kinetic ageing model; Catalyst ageing; Fe-BEA;

    Sammanfattning : Due to globalization and an increasing transport sector the interest for more fuel efficient combustion engines operating under lean conditions has increased. The products formed during the burning process in internal combustion engines are major contributants to global air pollution, where carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxides (NOX) are the major toxic components regulated in many countries. LÄS MER