Sökning: "lean burn"

Visar resultat 6 - 10 av 36 avhandlingar innehållade orden lean burn.

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

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

   Sammanfattning : 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. LÄS MER

3. 7. Studies of the influence of ZSM-5 synthesis on activity and stability of Cu-ZSM-5 in leand NOx reduction

   Författare :Malin Berggrund; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; HC-SCR; Cu-ZSM-5; catalysis; propene; lean NOx reduction; hydrothermal stability;

   Sammanfattning : 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 exhaust gases, which are in excess oxygen, where a conventional three-way catalyst cannot be used to reduce NOx. LÄS MER

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

   Författare :Anna Maria Lindholm; Chalmers tekniska högskola; []
   Nyckelord :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;

   Sammanfattning : 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. LÄS MER

5. 9. Deactivation mechanisms influencing the performance and durability of exhaust aftertreatment systems

   Författare :Jesus De Abreu Goes; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Thermal degradation; Gasoline particulate filters; Lean NOx traps; Sulfur poisoning.;

   Sammanfattning : As countermeasure to air pollution and global warming, more stringent environmental policy measures will probably come into force with the future emission standards, which will require important developments for gasoline and diesel vehicles to meet the emerging criteria. Efficient catalytic formulations and advanced strategies for exhaust aftertreatment systems will be therefore demanded to provide both high catalytic activity and stability, minimizing the environmental impact by automobiles. LÄS MER

7. 10. Experimental and kinetic studies of H2 effect on lean exhaust aftertreatment processes: HC-SCR and DOC

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

   Sammanfattning : With a growing concern to lower greenhouse gas emissions from road transportation, lean burn and diesel engines will keep playing an important role in the future. Development of a highly efficient and durable process to reduce NOx to N2 becomes a challenging issue especially in the presence of ample O2 concentration as in lean burn exhaust. LÄS MER