Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Package 4 Reduction of automotive emission, exhaust gas catalysts for Otto and Diesel engines, hybrid drive, fuel cells A. Tungler BUTE Reactions and products in the engine and in the catalytic converter A. Tungler BUTE Reactions and products in the catalytic converter A. Tungler BUTE A. Tungler BUTE A. Tungler BUTE Development of automotive catalysts A. Tungler BUTE A. Tungler BUTE Hydrocarbon trap A. Tungler BUTE Working of the electrically heated catalyst A. Tungler BUTE A. Tungler BUTE A. Tungler BUTE A. Tungler BUTE A. Tungler BUTE Oxygen storage in three way catalysts A. Tungler BUTE New oxygen storage material: ACZ alumina between cerium and zirconium oxide The diffusion barrier concept for ACZ compared with CZ. (a) ACZ: the sintering of CZ is inhibited by Al2O3 particles dispersed among CZ particles; (b) CZ: sinter easily without any dispersal. A. Tungler BUTE The TWC catalyst is not effective in reducing NOx when the engine is operated lean of the stoichiometric air to fuel ratio (λ > 1). Lean operation Fuel reach operation Only for <1 s A. Tungler BUTE A. Tungler BUTE A. Tungler BUTE Decreasing of sulfur poisoning Combination of TiO2 and -Al2O3 --- to minimize the amount of SOx deposition, hexagonal cell monolithic substrate--- to enhance the removal of sulfate, Rh/ZrO2-added catalyst --- has high activity of hydrogen generation via steam reforming. Photographs of wash-coat layer on square-cell (left) and hexagonal-cell (right) monolithic substrate. A. Tungler BUTE Non-desirable reaction: The catalytic reactions are: A. Tungler BUTE Diesel particulate trap with burner A. Tungler BUTE Catalytic particulate trap A. Tungler BUTE Hybrid driving Gasoline engine - The hybrid car has a gasoline engine much like the one you will find on most cars. However, the engine on a hybrid is smaller and uses advanced technologies to reduce emissions and increase efficiency. Fuel tank - The fuel tank in a hybrid is the energy storage device for the gasoline engine. Gasoline has a much higher energy density than batteries do. For example, it takes about 1,000 pounds of batteries to store as much energy as 1 gallon (7 pounds) of gasoline. Electric motor - The electric motor on a hybrid car is very sophisticated. Advanced electronics allow it to act as a motor as well as a generator. For example, when it needs to, it can draw energy from the batteries to accelerate the car. But acting as a generator, it can slow the car down and return energy to the batteries. Generator - The generator is similar to an electric motor, but it acts only to produce electrical power. It is used mostly on series hybrids. Batteries - The batteries in a hybrid car are the energy storage device for the electric motor. Unlike the gasoline in the fuel tank, which can only power the gasoline engine, the electric motor on a hybrid car can put energy into the batteries as well as draw energy from them. Transmission - The transmission on a hybrid car performs the same basic function as the transmission on a conventional car. Some hybrids, like the Honda Insight, have conventional transmissions. Others, like the Toyota Prius, have radically different ones. A. Tungler BUTE A. Tungler BUTE Fuel cells The principle operation of a fuel cell is comparable to that of a battery. In contrast to batteries — where the chemical energy is stored in substances inside the battery — fuel cells are just converting systems, the reagents have to be supplied continuously to the fuel cell in order to obtain electricity. Thus, fuel cells are systems which convert chemical energy directly into electricity in an invariant electrochemical set-up. A. Tungler BUTE Comparison between the two conversion routes of fossil fuel into electric energy. The chemical energy of the fuel is directly converted into electrical energy by fuel cells, in conventional systems the chemical energy of the fuels is converted first into thermal energy, than in mechanical energy and finally into electrical energy. In the reformer hydrocarbons or methanol are converted to CO and H2, according to A. Tungler BUTE Efficiency as a function of temperature of the energy conversion of a fuel cell and a conversion process limited by the Carnot's factor. A. Tungler BUTE Efficiency of energy conversion as a function of the size of the power plant; conventional systems are compared with projected fuel cell systems such as PAFC and SOFC A. Tungler BUTE A Siemens PEMFC stack Rated power 40 kW Voltage at rated power 109 V Open circuit voltage 160 V Rated current 350 A Size (without tierals) 41 × 41 × 5 6 cm3 Volume 94 L Weight 280 kg Number of cells 160 Integrated H2 humidifier A. Tungler BUTE Fuel cell system for stationary production of electricity and heat A complete fuel cell system comprises besides the electrochemical device other components such as gas compressors, reformers, catalytic burner, and d.c./a.c. converter. A. Tungler BUTE Materials used for the components of different fuel cell systems A. Tungler BUTE Operating parameters of different types of fuel cells A. Tungler BUTE A. Tungler BUTE Proton exchange membrane fuel cell: the membrane – electrode assembly (MEA) consists of the Nafion membrane with the electrocatalyst on the surface in contact with porous carbon electrodes. Each MEA is mounted between two gas manifolds in an electrical insulating MEA frame and it is separated by an interconnector plate from the adjacent MEAs. A. Tungler BUTE Sketch of the electric car Necar III developed by Daimler-Benz A. Tungler BUTE Components and processes for a fuel cell with an acidic electrolyte. A. Tungler BUTE TEM-picture of a 20 wt.% Pt3Sn/Vulcan E-TEK catalyst A. Tungler BUTE