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Archiv: Februar 2010

Résumé
Les transports sont responsables de nombreuses externalités, parmi lesquelles deux concernent la pollution atmosphérique : les gaz à effet de serre et la pollution locale (particules, NOX,…). Dans la recherche de politiques optimales de transport, ces deux externalités ont le plus souvent été analysées de manière indépendante. Nous proposons un modèle de décision séquentielle qui prend en compte conjointement ces deux types de pollution et intègre l’irréversibilité des politiques entreprises ainsi que la possibilité d’une réduction progressive des incertitudes par arrivée d’information. Nous trouvons d’une part qu’une analyse conjointe des deux sources d’externalités est nécessaire, et d’autre part que des mesures structurelles – qui réduisent les besoins en transports individuels – sont économiquement plus intéressantes que des mesures technologiques – qui réduisent les émissions de polluants. Nous illustrons l’intérêt d’une analyse jointe des externalités par deux exemples en matière de fiscalité automobile et de politique du logement.

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Vorwort
Wie sieht das Auto der Zukunft aus? Politik, Forschung und Industrie versuchen derzeit eine Antwort auf diese Frage zu finden. Es wurden bereits zahlreiche Lösungen gefunden und verschiedene Förderprogramme unterstützen die Forschung und Entwicklung auf diesem Gebiet, insbesondere bezüglich neuer Antriebstechnologien und Energiespeicher. Vor dem Hintergrund einer Ressourcenknappheit sind Verkehrsangelegenheiten und Umweltbelastungen in den Vordergrund gerückt. Angesichts des Ziels einer Senkung der CO2-Emissionen sieht sich die Automobilindustrie der Herausforderung gegenüber, innovative alternative Antriebstechnologien zu entwickeln. Deutschland nimmt in diesem Bereich bereits eine Vorreiterrolle ein. Die Bundesregierung fördert seit einigen Jahren zahlreiche Forschungsprogramme. Deutschland soll ein Leitmarkt für Elektromobilität werden, d.h. für Elektround Hybridfahrzeuge. Ziel der Bundesregierung ist es, dass bis 2020 eine Million Elektrofahrzeuge auf Deutschlands Straßen fahren.

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Bedeutung der Automobilindustrie
Ein solcher Einbruch der weltweiten Märkte ist vor dem Hintergrund der hohen Bedeutung der Automobilindustrie für Deutschland gravierend. Sie ist der wichtigste Wirtschaftszweig in Deutschland. Mit einem Umsatz von fast 290 Mrd. Euro leistet die Branche gut 20 Prozent des Gesamtumsatzes der deutschen Industrie. Die Automobilindustrie spielt die wichtigste Rolle im Ringen um den Titel „Exportweltmeister Deutschland“. Drei von vier in Deutschland gebaute Autos gehen an Kunden im Ausland. 2008 hat die deutsche Automobilindustrie Erzeugnisse im Wert von fast 180 Mrd. Euro exportiert und Fahrzeuge und Teile im Wert von knapp 78 Mrd. Euro importiert. Der Handelsbilanzüberschuss mit automobilen Erzeugnissen liegt damit bei etwa 102 Mrd. Euro und leistet einen äußerst wichtigen Beitrag zum Handelsbilanzüberschuss der gesamten deutschen Wirtschaft.

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1. Introduction
The selective catalytic reduction (SCR) of NO with NH3 process has been studied by many investigations in recent years with copper-based catalysts for conversion of NO, since the copper-containing catalysts (zeolite- and oxide-based catalysts) have high catalytic activity. The reduction mechanism of NO over Cu-zeolite, in the absence of oxygen, has been investigated and it was found that the CuO-based catalysts containing Cu-zeolite have a high activity for the reaction of NO with NH3.1,2 Also, CuO/zeolite catalyst has a distinct advantage of decreasing NH3 oxidation over other catalysts to remove NOx.3 T self-inhibiting effect of NOx in the SCR of NOx in a diesel engine over a Cu-zeolite catalyst has also been observed. This effect is strongest at lower temperatures (<250 °C) and became negligible above 300 °C.4 It is also reported that CuO/γ-Al2O3 catalyst has two possible reaction pathways of NO reduction to N2, one via a nitrosoamide-like intermediate and second via an ammonium nitrate-like intermediate or their equivalent Cu complexes [NO-Cu-NH2 and NO2-Cu-NH4, respectively]. The reaction mechanism of the SCR of NO with NH3 in the presence of O2 over CuO/γ-Al2O3 catalyst has also been summarized.

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ABSTRACT

Realizing the need for e®ective kinetic models that could be used over wide op-erating regimes, oxidation and storage kinetics for a diesel oxidation catalyst (DOC) were developed in this work. As a first step towards kinetics development, a simple catalyst formulation including only Platinum was chosen. Kinetics were generated by assuming that propylene was representative all the hydrocarbons (HCs) in the exhaust. A systematic methodology was formulated which consisted of (1) careful choice of concentration/temperature domain (2) measurement of reactor conversions of aged catalyst samples at chosen test points using a high space velocity integral reactor (3) developing a simplified 1D reactor model (4) defining an objective func- tion which is critically sensitive to the differences between model predictions and experiments at all conversions (5) generating proper initial guesses and finally (6) modifying Langmuir-Hinshelwood rate expressions to arrive at the final rate forms. This methodology can be used to generate steady state global kinetics in general.

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INTRODUCTION

Since its introduction more than a century ago, the automobile has been in a state of continuous development in response to society’s needs and expectations. It continues to evolve today in line with contemporary requirements, not only as a vital element in global economic activity as a means of commercial and passenger transport, but also as a means of enhancing people’s lives. As a result of its constant evolution, the automobile is today a comfortable and convenient means of transportation that offers greater safety than ever before and significantly reduced environmental impact, in addition to highly improved operational performance.

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The future of diesel is cleaner and more efficient
•CO2regulations are just starting. 80+% in-use fleet reductions needed by 2050
•Criteria pollutant regulations also tightening
•Diesel engines are advancing with much more opportunity for efficiency
•DeNOx is getting better; 90%+ SCR efficiency in commercial vehicles
•DPF is getting more efficient and optimized
•“Passive”filter management a real possibility
•DOCs emerging for most difficult applications

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Although cars are ubiquitous today, the technology that is so pivotal to the modern life of Americans an Europeans is relatively young. The introduction of the gasoline-fueled internal combustion engine dates back only to 1885. By 1888, Karl Benz, a German engineer and the inventor of the modern automobile, had launched the first line of mass-produced cars in Germany. The U.S., France and then Britain soon followed suit.

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ABSTRACT
“Worldwide emission regulation has been tightening year after year. Numbers of researchers are trying to work out combinations of key technologies to meet the forth-coming emission norms. Exhaust gas recirculation (EGR) for diesel engine to reduce oxides of nitrogen is chosen for present work. The emphasis is given on oxides of nitrogen (NOx). Experiments were carried out on computerized single cylinder four- stroke diesel engine with eddy current dynamometer (10 BHP 7.4 KW).” “Exhaust gas re-circulation set-up is developed. It consists of EGR cooler; air filters box, rota-meter, exhaust control valve, pressure gauge and temperature indicator etc. Engine set-up was modified and coupled with EGR setup. Exhaust gas recirculation system was tested with different EGR percentage. i.e. 0 %, 8 %, 12 %, 15 % & 23 %. Effect of EGR on smoke, NOx and other performance parameters like smoke opacity, brake thermal efficiency, specific fuel consumption were studied. There is considerable reduction in oxides of nitrogen  (NOx).”

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2010 1 Feb

EGR vs SCR? Making sense of it all

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In 2010, the U.S. Environmental Protection Agency will be changing its emissions standard to two-tenths of a gram of nitrogen oxides per horsepower hour. This significant reduction will force the diesel engine industry to react strongly to meet the requirements. It’s not too soon to start thinking about which EPA-compliant engine you’ll be buying: a smaller, lighter one that requires urea as an additive, or a larger, heavier one that doesn’t. So – let’s start with the basics:

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