Search for dissertations about: "N2O formation"

Showing result 1 - 5 of 21 swedish dissertations containing the words N2O formation.

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

    Author : Joonsoo Han; Chalmers tekniska högskola; []
    Keywords : 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;

    Abstract : 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. READ MORE

  4. 2. NOx Storage and Reduction Catalysts. Reduction with Hydrogen and the Influence of Water and Carbon Dioxide

    Author : Anna Maria Lindholm; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NSR catalyst; Pt Ba Al; H2O; CO2; Pt Al; NOx reduction; H2; NH3 formation; NOx storage; Lean NOx Trap; N2O formation; kinetic modeling; Pt Si;

    Abstract : Environmental concern has increased over the past several years and resulted in stringent emission legislation on NOx, CO, and hydrocarbon emissions from automobile exhausts. Moreover, the demands to improve the fuel efficiency of engines and to lower the CO2 emissions have increased, and a way to meet this is by using lean burn engines which operate with oxygen excess. READ MORE

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

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

    Abstract : 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. READ MORE

  6. 4. Fundamentals of NH3-SCR and SOx chemistry over copper zeolite for the control of NOx and greenhouse gas (N2O) emissions

    Author : Joonsoo Han; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; DeNOx; Cu SSZ-13; NH3-SCR; N2O; EATS; SO3; ammonium nitrate; SO2;

    Abstract : The release of N2O over Cu-zeolite was investigated due to the critical contribution it makes to the atmosphere as one of the greenhouse gases (GHGs). An exhaust after-treatment system (EATS) for heavy-duty vehicles that uses Cu/SSZ-13 as the selective catalyst reduction (SCR) catalyst experiences not only a variety of flow, temperature and chemical conditions but is also exposed to various resulting contaminants. READ MORE

  7. 5. Redox Reactions of NO and O2 in Iron Enzymes : A Density Functional Theory Study

    Author : Mattias Blomberg; Per Siegbahn; Adrian Mulholland; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; enzyme catalysis; redox reactions; cytochrome oxidase; nitric oxide reductase; hyponitrous acid anhydride; peroxynitrite; myoglobin; prostaglandin synthase; PGHS; NO; N2O; O2; CO; Chemical physics; Kemisk fysik;

    Abstract : In the present thesis the density functional B3LYP has been used to study reactions of NO and O2 in redox active enzymes.Reduction of nitric oxide (NO) to nitrous oxide (N2O) is an important part in the bacterial energy conservation (denitrification). READ MORE