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Visar resultat 1 - 5 av 14 avhandlingar som matchar ovanstående sökkriterier.
1. Studies of the influence of ZSM-5 synthesis on activity and stability of Cu-ZSM-5 in leand NOx reduction
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
2. Hydrothermally induced changes of lean NOx reduction over Cu-ZSM-5 and stability improvements by synthesis modification
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. Partial Oxidation of Methane over Functionalised Zeolites and Zeotypes
Sammanfattning : Partial oxidation of methane to methanol is an industrially important process that allows natural gas and biogas to be utilised for methanol-based production of chemicals or converted to liquid methanol fuel, which make transportation more facile. In this thesis, the activity for partial oxidation of methane to methanol over copper functionalised zeolites and silica supported copper is investigated using a three-step quasi-catalytic approach including catalyst activation, methane reaction and methanol extraction by water. LÄS MER
4. Lean NOx reduction by alternative fuels - with focus on catalysts for dimethyl ether
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
5. NOx reduction with dimethyl ether in lean exhaust
Sammanfattning : There is a growing concern worldwide about the increase in anthropogenic greenhouse gas emissions, particularly carbon dioxide (CO2) from the combustion of fossil fuels. Vehicles with internal combustion engines contribute significantly to these emissions, which has led to an increased demand for engines running on alternative (non-fossil) fuels. LÄS MER