Sökning: "SCR catalysts"

Visar resultat 1 - 5 av 47 avhandlingar innehållade orden SCR catalysts.

1. 1. Studies on metal oxide catalysts for selective catalytic reduction of NOx with NH3 -Influence of preparation procedure and feed gas transients

   Författare :Mikaela Wallin; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; ammonia; transient ammonia supply; microemulsion; perovskites; metal oxide catalysts; zeolite H-ZSM-5; NOx; SCR;

   Sammanfattning : .... LÄS MER

3. 2. Lean NOx reduction with methanol over supported silver catalysts

   Författare :Marika Männikkö; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; lean NOx reduction; SCR; silver species; silver alumina; methanol; hydrogen; silver ZSM-5;

   Sammanfattning : The oxygen rich and relatively cold exhaust gases from fuel-efficient combustion engines bring challenges for the reductive aftertreatment of NOx. In this context selective catalytic reduction over silver/alumina has shown positive results, especially with oxygenated reducing agents. LÄS MER

4. 3. Nitrous Oxide Formation over Zeolite-based Catalysts during Ammonia-SCR: The Effect of Framework Structure, Acidity, and Copper Content

   Författare :Ghodsieh Isapour Toutizad; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Copper content; In situ IR spectroscopy; Heterogeneous catalysis; N2O; Si Al molar ratio; SCR; Zeolites;

   Sammanfattning : The emission control of anthropogenic nitrous oxide (N2O), a by-product formed  through fossil- and renewable fuel combustion, agricultural activities, and industrial  chemical processes, has attracted large considerations due to its substantial contribution  in global warming and ozone layer depletion. Selective catalytic reduction with  ammonia (NH3-SCR) is the most prevailing technology for the abatement of nitrogen  oxides (NOx) in the exhaust gases from lean-burn processes, with the possible formation  of N2O. LÄS MER

5. 4. Studies on Lean NOx Reduction with Ammonia. Catalysts and Sensors

   Författare :Mikaela Wallin; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; catalysis; Pt SiO2; NOx reduction; gas sensor; DFT; SCR; H-ZSM-5; in situ FTIR; LCAO; DRIFT; high throughput screening; transient ammonia supply; ammonia; microemulsion; perovskite;

   Sammanfattning : Selective catalytic reduction of NOx with ammonia, NH3-SCR, is a promising technique to reduce NOx under lean conditions, e.g. in diesel engine exhausts. The main objective of this thesis was to gain further understanding of key parameters affecting the performance of catalysts and sensors for NH3-SCR. LÄS MER

7. 5. 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