Sökning: "N2O reduction"

Visar resultat 11 - 15 av 34 avhandlingar innehållade orden N2O reduction.

1. 11. Kinetic Studies of NOx Storage and Reduction Catalysts - Flow Reactor Experiments and Microkinetic Modeling

   Författare :Anna Maria Lindholm; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NOx reduction; flow reactor experiments; NOx storage; Pt Ba Al; NSR catalyst; microkinetic modeling; combined NSR and SCR system;

   Sammanfattning : The NOx storage and reduction (NSR) technology is a promising technique to reduce NOx during oxygen excess e.g. in lean burn engine exhaust. A typical NSR catalyst consists of the following components: precious metals, such as platinum, palladium or rhodium, a storage component, usually barium, and a high surface area support, such as γ-alumina. LÄS MER

3. 12. Electron and Proton Transfer in Nitric Oxide Reductase : NO Binding, NO Reduction and no Pumping

   Författare :Peter Lachmann; Pia Ädelroth; Peter Brzezinski; Fahmi Himo; Stockholms universitet; []
   Nyckelord :Flow-Flash; Nitric Oxide Reductase; Heme Copper Oxidase;

   Sammanfattning : Nitric oxide reductase (NOR) from Paracoccus denitrificans catalyzes the two electronreduction of NO to N2O (2NO + 2H+ + 2e- → N2O + H2O) as part of the process ofdenitrification, the step-wise reduction of nitrate to dinitogen. The NOR-catalyzedreaction is central in the nitrogen cycle, since in this step the N=N double bond isformed. LÄS MER

4. 13. Nitrous Oxide Emission from Circulating Fluidized Bed Combustion

   Författare :Lars-Erik Åmand; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; air supply dependence; fluidized beds; homogeneous heterogeneous reactions; fluidized-bed boilers; bed temperature dependence; N2O emissions; circulating fluidized-bed boilers; gas-concentration profiles;

   Sammanfattning : In the present thesis N2O results are presented from several measurement projects on two commercial circulating fluidized bed (CFB) boilers. Traditional parameter studies have been carried out, as well as test programs where various nitrogen-containing species were injected into the furnace or gas-concentration profiles in the combustion chamber were measured. LÄS MER

5. 14. 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

7. 15. Imprint of management on microbial communities in arable soil : implications for N2O emissions

   Författare :Tina Putz; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

   Sammanfattning : Arable soils are a major source of the greenhouse gas nitrous oxide (N2O), emissions of which are directly linked to increased use of N fertilizers. Microbial communities that drive N cycle processes in soil ultimately determine the fate of reactive N inputs and control N2O emissions. LÄS MER