Sökning: "alumina active"

Visar resultat 6 - 10 av 44 avhandlingar innehållade orden alumina active.

1. 6. Lean NOx reduction over supported silver catalysts with methanol as reductant - Influence of silver loading, support material, hydrogen addition and C/N molar ratio

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

   Sammanfattning : The aim of this thesis is to find catalysts which show high activity and selectivity forlean NOx reduction in the low-temperature regime relevant for diesel and lean-burnengines and to investigate methanol as reducing agent. The lean NOx reduction oversupported silver catalysts is studied, focusing on the influence of the support material,silver loading, addition of hydrogen and the C/N molar ratio. LÄS MER

3. 7. 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

4. 8. Kinetic Studies of NO Oxidation and Reduction over Silver-Alumina Catalyst

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

   Sammanfattning : 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. LÄS MER

5. 9. Lean NOx reduction over silver-alumina catalysts - Aspects on synthesis, structure and activity

   Författare :Hannes Kannisto; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; freeze-drying; HC-SCR; DRIFTS.; aromatic hydrocarbons; silver-alumina; Lean NOx reduction; selective catalytic reduction; sol-gel; characterization; catalyst preparation; kinetic modeling;

   Sammanfattning : The aim of this thesis is to increase the understanding of how to design highly active silver-alumina catalysts for selective catalytic reduction of NOx with hydrocarbons (HC-SCR) in oxygen excess at low temperatures (150-250 °C). Silver-alumina catalysts have been prepared using different methods, including a new unique preparation method developed during the thesis project. LÄS MER

7. 10. Influence of alumina on the zinc slag fuming processes : an experimental study on physical properties and leaching behaviour of the generated fayalite-type slag

   Författare :Sina Mostaghel; Heikki Kusti Jaikanen; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Physical properties; Thermodynamic calculations; environmental properties; Sustainable extraction; Zinc fuming; Copper; Process Metallurgy; Processmetallurgi;

   Sammanfattning : Recycling of secondary raw materials by non-ferrous metal producers is steadily increasing. These materials inevitably introduce various impurities to the production furnaces, which can change the chemical composition, and thereafter, the physical and chemical properties of the products and by-products of the operation. LÄS MER