Sökning: "NH3-SCR"

Visar resultat 1 - 5 av 17 avhandlingar innehållade ordet NH3-SCR.

  1. 1. Synthesis and functionalization of zeolites for NH3-SCR applications

    Författare :Alexander Shishkin; Chalmers University of Technology; []
    Nyckelord :NATURVETENSKAP; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; NATURAL SCIENCES; ENGINEERING AND TECHNOLOGY; ENGINEERING AND TECHNOLOGY; NH3-SCR; NOx reduction; Environmental catalysis; hydrothermal synthesis.; exhaust aftertreatment; zeolite functionalization;

    Sammanfattning : In the strive towards decreasing carbon dioxide emissions from the growing transport sector, the interest for more fuel-efficient combustion engines operating under lean (oxygen excess) conditions has increased. The combustion products, however, formed in such engines contribute considerably to air pollution. LÄS MER

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

    Författare :Soran Shwan; Chalmers University of Technology; []
    Nyckelord :modeling; NOX.; Hydrothermal; Chemical; Kinetic; Copper; Deactivation; Iron; Zeolite; Nitrogen oxides; NH3; Ammonia; Catalyst; NSR; Emissions; Poisoning; Ageing; NH3-SCR;

    Sammanfattning : 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). LÄS MER

  3. 3. On the Character of Active Sites in Copper Exchanged Zeolites during NH3-SCR

    Författare :Lin Chen; Chalmers University of Technology; []
    Nyckelord :NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; NATURAL SCIENCES; Cu-SSZ-13; SSIE; O2-dissociation; Al-distribution; NH3-SCR; Chabazite; O2-activation;

    Sammanfattning : Nitrogen oxides (NOx) are formed during combustion in diesel engines and one current approach to reduce NOx to N2 is selective catalytic reduction with NH3 as reducing agent (NH3-SCR). To acquire both high activity and selectivity, the active site is often atomically dispersed metal atom, so-called single-site catalysts. LÄS MER

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

    Författare :Soran Shwan; Chalmers University of Technology; []
    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

  5. 5. NH3-SCR chemistry for NOx abatement: Influence of zeolite support on N2O formation & phosphorus species addition

    Författare :Joonsoo Han; Chalmers University of Technology; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Copper; NH3 SCR chemistry; Zeolite topology; N2O; Phosphorus poisoning;

    Sammanfattning : Different lattice arrangements of Si, Al, and O atoms result in a variety of pore dimensions and zeolite channel network systems, giving rise to different physicochemical environments inside the catalyst cage. The objective of the thesis work was to understand the influence of zeolite topology on NH3-assisted SCR chemistry over CHA, MFI, and BEA frameworks, on the formation of N2O and the addition of phosphorus species to attain fundamental insight into NOx emission control. LÄS MER