Sökning: "NH3 SCR chemistry"

Visar resultat 1 - 5 av 20 avhandlingar innehållade orden NH3 SCR chemistry.

  1. 1. Reaction kinetics of NH3-SCR over Cu-CHA from first principles

    Författare :Yingxin Feng; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Catalysis; microkinetic modeling; density functional theory; Cu-CHA; ammonia assisted selective catalytic reduction;

    Sammanfattning : Ammonia-assisted selective catalytic reduction (NH3-SCR) is an advanced technology to reduce nitrogen oxide (NOx) emissions from lean-burn engines. NH3 is added to the exhaust gas and reacts selectively with NOx, forming N2 and H2O. 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. NH3-SCR chemistry for NOx abatement: Influence of zeolite support on N2O formation & phosphorus species addition

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

  5. 4. Active sites and influence of reaction conditions on the selective catalytic reduction of NOx over the silver-alumina catalyst

    Författare :Linda Ström; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; microemulsion; nanoalloys; DRIFTS; HC-SCR; indium; palladium; silver; XRD; UV-vis; alumina; NH3-TPD.; Lean NOx reduction; TEM; NH3-SCR;

    Sammanfattning : Hazardous nitrogen oxides (NOx) are challenging to remove from fuel-efficient excess-oxygen operating engines. A promising solution is selective catalytic reduction (SCR) of NOx, using hydrocarbons (HC-SCR) or ammonia (NH3-SCR) as reducing agent. LÄS MER

  7. 5. The effect of framework structure on N2O formation over Cu-based zeolites during NH3-SCR reactions

    Författare :Ghodsieh Isapour Toutizad; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; CHA; MFI; Zeolites; SCR; Ammonium nitrate; Nitrous Oxide; BEA; Infrared spectroscopy; Catalysis;

    Sammanfattning : Anthropogenic nitrous oxide (N2O), which is generally formed as a byproduct of industrial chemical processes and fossil fuel combustion, has attracted significant attention in recent years due to its destructive role in global warming and ozone layer depletion. Among different developed technologies applied for lean NOx reduction, the selective catalytic reduction (SCR) of NOx with ammonia (as a reducing agent) is presently the most used method. LÄS MER