Search for dissertations about: "HC-SCR"

Showing result 6 - 10 of 16 swedish dissertations containing the word HC-SCR.

  2. 6. Exhaust aftertreatment under lean conditions, regenerable SOx traps and NOx reduction catalysts

    Author : Lisa Kylhammar; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Heterogenous catalysis; Selective catalytic reduction; HC-SCR; Sulfur storage; SOx trap; Spectroscopy; Lean exhausts; NOx; Ag Al2O3; DRIFT; XPS;

    Abstract : The aim of this thesis was to investigate i) potential materials for regenerable SOx traps and ii) the influence of silver distribution within Ag/Al2O3 catalysts on the selective reduction of NOx by hydrocarbons (HC-SCR). Both areas are highly relevant for present and future vehicle aftertreatment technologies for lean exhausts. READ MORE

  4. 7. Lean NOx reduction over silver-alumina from lab-scale to real conditions - Effects of reducing agent and catalyst composition

    Author : Fredrik Gunnarsson; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; ethanol; Ag Al2O3; Pt-doping; Lean NOx reduction; HC-SCR; low-temperature activity; catalyst ageing; biofuels;

    Abstract : Lean NOx reduction over silver-alumina from lab-scale to real conditions Effects of reducing agent and catalyst compositionFREDRIK GUNNARSSONApplied surface chemistryDepartment of Chemical and Biological EngineeringChalmers University of TechnologyAbstractThe focus of this work is to increase the understanding of lean NOx reduction over silver-alumina catalysts using hydrocarbons as the reducing agent (HC-SCR), in particular by investigating the effect of silver loading, the role of platinum doping, and the effect of the type of reducing agent. In addition, the effects of aging and hydrothermal treatment on the catalytic activity and selectivity, and the influence of real engine exhausts were investigated, with special attention to the low-temperature activity. READ MORE

  5. 8. Hydrothermally induced changes of lean NOx reduction over Cu-ZSM-5 and stability improvements by synthesis modification

    Author : Malin Berggrund; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; hydrothermal stability; Cu-ZSM-5; propene; lean NOx reduction; HC-SCR; in-situ DRIFT;

    Abstract : The growing concern about the global warming coupled with the increasing emissions of the greenhouse gas carbon dioxide, combined with the climbing oil price, drives the interest to more fuel efficient lean combustion engines for automotive applications. Such engines require new technical solutions for reduction of NOx in the oxygen rich exhaust gases, where a conventional three-way catalyst cannot be used. READ MORE

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

    Author : Linda Ström; Chalmers tekniska högskola; []
    Keywords : 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;

    Abstract : 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. READ MORE

  7. 10. Kinetic Studies of NO Oxidation and Reduction over Silver-Alumina Catalyst

    Author : Muhammad Mufti Azis; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TPD; Silver Alumina; HC-SCR; Kinetic modeling; Hydrogen effect; NOx reduction; NO oxidation.;

    Abstract : In line with growing concerns to manufacture more environmentally friendly vehicles, the use of internal combustion engines operating with oxygen excess or so called lean-burn engines will continue to be increasingly used. For lean-burn operation, reduction of NOx (NO+NO2) emissions is a major challenge and it is therefore urgently required to develop efficient and reliable NOx reduction aftertreatment systems for a wide variety of lean-burn or diesel engines. READ MORE