Sökning: "NH3"

Visar resultat 21 - 25 av 129 avhandlingar innehållade ordet NH3.

  1. 21. NH3-SCR over Cu-zeolite catalysts: activity and deactivation studies

    Författare :Kurnia Wijayanti; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Cu‑SAPO-34; internal mass transfer limitation; NH3‑SCR; Cu-zeolite; hydrothermal aging; SO2 poisoning; Cu‑Beta; Cu‑SSZ‑13;

    Sammanfattning : NOx emission is one of the major contributors to air pollution especially in the urban environment. The most frequently applied technique to reduce NOx from diesel engine is to employ ammonia selective catalytic reduction (NH3-SCR) using Cu‑zeolite as the catalyst. LÄS MER

  3. 22. Fundamental studies of catalytic systems for diesel emission control

    Författare :Xavier Auvray; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NH3 SCR; NO oxidation; sulfur; hysteresis; kinetic modeling; SpaciMS; catalyst acidity; DOC; aging; Pt Al2O3;

    Sammanfattning : Due to global lean exhaust gas and new emission regulations, exhaust aftertreatment systems of diesel engines are more and more sophisticated and composed of a series of catalytic units. In the present work, two of these catalytic systems were studied with different approach. LÄS MER

  4. 23. NOx Storage and Reduction Catalysts. Reduction with Hydrogen and the Influence of Water and Carbon Dioxide

    Författare :Anna Maria Lindholm; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NSR catalyst; Pt Ba Al; H2O; CO2; Pt Al; NOx reduction; H2; NH3 formation; NOx storage; Lean NOx Trap; N2O formation; kinetic modeling; Pt Si;

    Sammanfattning : Environmental concern has increased over the past several years and resulted in stringent emission legislation on NOx, CO, and hydrocarbon emissions from automobile exhausts. Moreover, the demands to improve the fuel efficiency of engines and to lower the CO2 emissions have increased, and a way to meet this is by using lean burn engines which operate with oxygen excess. LÄS MER

  5. 24. Sintering of nickel catalysts in the presence of NH3/H2

    Författare :Johan Lif; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; stabilisation; hydrogen; nickel; ammonia; alumina; sintering; DFT calculation; catalyst deactivation;

    Sammanfattning : Supported metal catalysts are used in many important industrial processes, where amination of alcohols is one example. The exposure of the supported metal catalyst to reaction conditions results usually to a decrease in catalytic activity, by for instance thermal degradation. LÄS MER

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

    Författare :Sandra Dahlin; Lars Pettersson; Isabella Nova; KTH; []
    Nyckelord :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;

    Sammanfattning : 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). LÄS MER