Sökning: "NOx reduction"

Visar resultat 11 - 15 av 146 avhandlingar innehållade orden NOx reduction.

1. 11. Lean NOx reduction by alternative fuels - with focus on catalysts for dimethyl ether

   Författare :Sara U Erkfeldt; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; biofuel; In2O3; lean NOx reduction; alumina; Cu-ZSM-5; Ga2O3; DME; hydrocarbon-SCR; alternative fuel; NOx storage; B2O3; Ag Al2O3;

   Sammanfattning : There is an increased demand for diesel engines running on non-fossil fuels such as dimethyl ether (DME), biodiesel and synthetic diesel. DME is a promising alternative fuel with potential for high energy efficiency and low CO2 emissions. However, during all high temperature combustion NOx is formed, which may require exhaust aftertreatment. LÄS MER

3. 12. Nonlinear System Identification and Control Applied to Selective Catalytic Reduction Systems

   Författare :Soma Tayamon; Bengt Carlsson; Torbjörn Wigren; Bo Egardt; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Nonlinear identification; nonlinear control; selective catalytic reduction; NOx reduction; recursive prediction error method; feedback linearisation; multiple-model; Elektroteknik med inriktning mot reglerteknik; Electrical Engineering with specialization in Automatic Control;

   Sammanfattning : The stringent regulations of emission levels from heavy duty vehicles create a demand for new methods for reducing harmful emissions from diesel engines. This thesis deals with the modelling of the nitrogen oxide (NOx) emissions from heavy duty vehicles using a selective catalyst as an aftertreatment system, utilising ammonia (NH3) for its reduction. LÄS MER

4. 13. Lean NOx reduction with methanol over supported silver catalysts

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

   Sammanfattning : The oxygen rich and relatively cold exhaust gases from fuel-efficient combustion engines bring challenges for the reductive aftertreatment of NOx. In this context selective catalytic reduction over silver/alumina has shown positive results, especially with oxygenated reducing agents. LÄS MER

5. 14. 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. 15. Studies of a Heavy-Duty Diesel Aftertreatment System Based on the NOX Storage and Reduction Technology

   Författare :Klaus Papadakis; Avdelningen för kemiteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fuel penalty; injection parameters; DoE; design of experiments; exhaust; diesel engine; NO oxidation; simulation; modelling; oxidation catalyst; NOX trap; NOX storage and reduction; NSR; Kemiteknik och kemisk teknologi; Chemical technology and engineering; dosing strategy; system optimisation;

   Sammanfattning : The legislative limits for NOX emissions in the exhaust gas from heavy-duty diesel engines will be decreased in the European Union from today 3.5 g/kWh (Euro IV) to 2.0 g/kWh in 2008 (Euro V). In the USA and Japan a similar trend can be seen. LÄS MER