Sökning: "NH3-SCR"

Visar resultat 1 - 5 av 22 avhandlingar innehållade ordet NH3-SCR.

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

    Författare :Alexander Shishkin; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; 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

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

    Författare :Soran Shwan; Chalmers tekniska högskola; []
    Nyckelord :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;

    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

  4. 3. Dynamics and Reactivity of Cu-species in Cu-CHA for NH3-SCR

    Författare :Joachim Bjerregaard; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Machine Learning Force Field; Diffusion; Cu-CHA; NH3-SCR; DFT; Sulfur Deactivation;

    Sammanfattning : Copper exchanged chabazite (Cu-CHA) is a state-of-the-art catalyst for deNOx via ammonia assisted selective catalytic reduction (NH3-SCR) in lean burn engines, owing to its good low-temperature activity, and high hydrothermal stability. One challenge for Cu-CHA is, however, the sensitivity to sulfur species, which are present in the exhaust gas. LÄS MER

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

    Författare :Lin Chen; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; 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

  7. 5. 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