Download Document 2468861

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