Sökning: "catalyst acidity"

Visar resultat 1 - 5 av 14 avhandlingar innehållade orden catalyst acidity.

1. 1. Catalysis for Lean NOx Reduction - Aspects of Catalyst Synthesis and Surface Acidity

   Författare :Hanna Härelind Ingelsten; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; lean NOx reduction; silica; alumina; FTIR; surface acidity; model catalysts; platinum; HZSM-5; w o microemulsion; aluminum-silicate; hydrocarbon;

   Sammanfattning : From both economic and environmental perspectives it is desirable to reduce the consumption of fossil fuels. One route to increase the fuel efficiency for vehicles is operation in oxygen excess. However, a major problem with this technique is the lean environment, which obstructs catalytic reduction of nitrogen oxides (NOx) to harmless nitrogen. LÄS MER

3. 2. Fundamental studies of catalytic systems for diesel emission control

   Författare :Xavier Auvray; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NH3 SCR; NO oxidation; sulfur; hysteresis; kinetic modeling; SpaciMS; catalyst acidity; DOC; aging; Pt Al2O3;

   Sammanfattning : Due to global lean exhaust gas and new emission regulations, exhaust aftertreatment systems of diesel engines are more and more sophisticated and composed of a series of catalytic units. In the present work, two of these catalytic systems were studied with different approach. LÄS MER

4. 3. Kraft lignin valorization by hydrotreatment over Mo-based sulfided catalysts

   Författare :Muhammad Abdus Salam; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Char; Bio-oil; Kraft Lignin; Hydrodeoxygenation; Y-zeolite; Metal sulfide; Depolymerization; Acidity;

   Sammanfattning : The production of green fuels and chemicals from bio-based feedstock can suppress the dependency on fossil resources and help mitigate global climate challenges. Kraft lignin is a thermochemically modified natural lignin obtained from the pulping process as a byproduct. LÄS MER

5. 4. Enhanced Catalytic Pyrolysis of Biomass for High-Quality Biofuel Production

   Författare :Devy Kartika Ratnasari; Weihong Yang; Pär Jönsson; Tobias Richards; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Al-MCM-41; lignocellulose biomass; H-ZSM-5; kinetic study; catalyst regeneration;

   Sammanfattning : The rapid increase in energy demand, the extensive use of fossil fuels, and the urgent need to reduce carbon dioxide emissions have raised concerns in the transportation sector, since transportation has been primarily dependent on fossil fuels. Biofuel from biomass can make significant contributions to overcome the expected depletion of fossil fuels and reduce carbon emissions. LÄS MER

7. 5. Catalyst Design for the Valorisation of Biomass-derived Furans into Aromatics

   Författare :Guido J.L. de Reijer; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; aromatics; 2; 5-dimethylfuran; gallium; biomass; furans; production of aromatics; zeolites; biomass conversion; catalysis;

   Sammanfattning : Anno 2023, mankind must strive towards a more sustainable chemical industry; one that does not solely rely on fossil fuels but also utilises renewable feedstocks such as biomass. Biomass can be catalytically converted into commodity chemicals such as aromatics, through intermediates like furans. LÄS MER