Search for dissertations about: "lean-burn"

Showing result 16 - 20 of 29 swedish dissertations containing the word lean-burn.

  2. 16. Particulate Flows in Aftertreatment Systems

    Author : Henrik Ström; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Modeling; Computational fluid dynamics; Exhaust gas aftertreatment; Particulate matter; Multiphase flow; Particulate flow;

    Abstract : Emissions from internal combustion engines contain many components that have a detrimental effect on the environment and on human health, such as nitrogen oxides (NOx) and particulate matter (PM). In addition, the final product of any combustion of fossil fuel - carbon dioxide (CO2) - contributes to global warming. READ MORE

  4. 17. Dynamics and Reactivity of Cu-species in Cu-CHA for NH3-SCR

    Author : Joachim Bjerregaard; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Machine Learning Force Field; Diffusion; Cu-CHA; NH3-SCR; DFT; Sulfur Deactivation;

    Abstract : Copper exchanged chabazite (Cu-CHA) is a state-of-the-art catalyst for deNOx via ammonia assisted selective catalytic reduction (NH3-SCR) in lean burn engines, owing to its good low-temperature activity, and high hydrothermal stability. One challenge for Cu-CHA is, however, the sensitivity to sulfur species, which are present in the exhaust gas. READ MORE

  5. 18. Reaction kinetics of NH3-SCR over Cu-CHA from first principles

    Author : Yingxin Feng; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Catalysis; microkinetic modeling; density functional theory; Cu-CHA; ammonia assisted selective catalytic reduction;

    Abstract : Ammonia-assisted selective catalytic reduction (NH3-SCR) is an advanced technology to reduce nitrogen oxide (NOx) emissions from lean-burn engines. NH3 is added to the exhaust gas and reacts selectively with NOx, forming N2 and H2O. READ MORE

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

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

    Abstract : 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. READ MORE

  7. 20. Studies of hydrocarbon-assisted selective catalytic reduction of nitrogen oxides - DME as reductant and reaction mechanism over silver/alumina

    Author : Stefanie Tamm; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ZSM-5; NCO; HC-SCR; Dimethyl ether; reaction mechanism; silver alumina;

    Abstract : Increasing amounts of carbon dioxide are attaining worldwide growing attention as one probable cause for global warming. Together with the expected peak in oil production and an increasing oil demand, this results in a greater interest in more fuel effective lean burn engines (i.e. operation with excess oxygen). READ MORE