2. Importance of Environment & Technologies
Environment Technologies
2010 System
Integration
Energy consumption
Importance
Functions
2000 Electronics
d System
Integrate
Emission CO2
1990
ics
Electron
Emission CO/HC/NOx
m
lic Syste
Hydrau
year year
3. Air Quality Impact of
the Catalytic Converter
More than 8x108 tons of combined
HC, CO, NOx were abated by 2000
References: Heck and Farrauto
Monograph: Vora & Ghosh.
4. Great success stories are continuing
100 % Engine Exhaust The development of automotive
emission control technology over the
> 98 %
last three and a half decades is one of
the greatest environmental success
<2% stories of this century.
O2
H2O
CO2 Compared to the 1960s the emission
N2
Catalyst of motor vehicles has dropped to a
fraction, the fuel economy has doubled.
< 0.05 % O2
> 1.95 % H2O
CO2
HC N2
CO
NOx
5. A Catalytic Converter
• Catalytic converters transform NOx, CO and HC into
N2, CO2 and H2O Can or shell
Mat
Ceramic Substrate with Catalytic Coating
N2
CO2
H2O
NOX
CO
HC
8. The overall catalytic reactions
OXIDATION:
2CO + O2 2CO2
Hydrocarbons + O2 CO2 + H2O
2H2 + O2 2H2O
REDUCTION:
NO + Hydrocarbons N2 + CO2 + H2O
2NO + 2CO N2 + 2CO2
2NO + 2H2 N 2 + H2 O
2NO + 5H2 2NH3 + 2H2O
CO + H2O H2 + 2CO2
H2O + Hydrocarbons H2 + 2CO2
9. Working: Theory of Active Sites
The Energy
Path of a
Catalysed &
Uncatalysed
Reaction.
The active site may be viewed as the point on the catalyst material crystalline where the
electronic forces are optimum for the catalytic reaction to take place.
CO and O2 are chemisorbed on the catalyst and can react readily because of their proximity and
orientation. The process of adsorption also results in weakening of the bond between the atoms
within the CO molecule because some of the energy is shared with the surface. Thus, the
adsorbed atoms of the molecules are less tightly bonded to the molecule and more easily
attracted to other atoms such as oxygen. The reaction between CO and oxygen is thus easier
and more rapid. The products having achieved a lower energy state must desorb at the same
temperature, freeing the active site for additional reactions.
18. High cell density metal substrates
If the cell density is increased with the same construction
size, the effective surface is enlarged accordingly.
This considerably increases the efficiency of the system.
Range: 50 to 1000 CPSI / 0.03 to 0.05 mm foil thickness.
20. TURBULENT METALLIC SUBSTRATES
These foils generate turbulence in the exhaust gas stream
and so greatly increase the efficiency of the catalyst.
Types:
•Radial flow near the wall in
the channels (TS design®)
•A reduction of diffusion
paths and the hydraulic
diameter and a repeat of the
entrance flow (LS design)
•Radially open, perforated
structures (PE designTM)
•A combination of PE and
LS structures.
29. Sr. Noble Metal Non-Noble Metal oxides
No.
1. Technology well-known and proven. ot commercially proven so far.
N
2. Pt-Pd as 2 way converter catalyst. Perovskite oxides LaCoOs/LaMnOs,
Lai-xSixCoi-yMyOs complex oxides.
3. Pt-Pd/Rh proven combination for 3 -way Binary Cu-Cr oxide not established My.
converter (Ratio 10:1, Europe 5:1, Mine
Ratio 16.5:1),
4. Lower light-off temp., active even at Active from 250°C onwards.
100°C.
5. Conversion efficiency high at high Conversion efficiency tends to flatten
temperatures. out at high temperatures, but
modifications are equally active.
6. Narrow A/F for efficient 3-way NO + CO-»1/2N2 + CO2 Possible in two
conversion. stages.
7. Not tolerant to high, continuous Pb level Could be made Pb-tolerant by a right
in gasoline. catalyst formulation.
8. Not affected by SO2 (20 ppm SO2 in Poisoned by SO2. Development of SO2
exhaust for 0.03 wt% S in gasoline). resistant formulations.
9. Ceramic substrate, washcoated with No Washcoat on ceramic substrate.
alumina and deposited with Pt/Rh (0. Direct deposition of Oxide precursors.
16/0.03 wt%Pt/Rh). (5-15 wt% as oxides).
COMPARISON OF NOBLE V/S. NON-NOBLE CATALYST
48. EMISSION DATA OF 4-STROKE ENGINED
MOTORCYCLE FITTED WITH CATALYTIC CONVERTER
49. EMISSION DATA OF 2-STROKE ENGINED MOPED
FITTED WITH CATALYTIC CONVERTER
50. MICROSTRUCTURE OFA FRESH METALLIC MICROSTRUCTURE OFA FRESH CERAMIC
CONVERTER CONVERTER
MICRO STRUCTURE AFTER
WASHCOAT ADHESION TEST
MICROSTRUCTURE OFA FRESH
CERAMIC CONVERTER AFTER SOME MICROSTRUCTURE SHOWING
HOURS OF ENGINE RUN POISONING BY CONTAMINANATS
59. Automotive Emissions
Importance of Cold Start
Tailpipe HC Emissions (FTP Bag 1)
0.025 1500
Tailpipe HC Mass (g/s)
Temperature, (Deg F)
0.02 1200
0.015 900
Catalyst "Light-Off"
X Temperature
0.01 600
0.005 300
0 0
0 100 200 300 400 500
Time (s)
Together with Emitec, we evaluated the potential of such a preturbo catalyst, shown here on the picture in the left upper corner. The addition of these catalysts to the standard system allowed on a modern diesel car to further improve the tailpipe emissions by about 30 %, as is apparent from the cumulated emissions over the NEDC, the red line with preturbo catalyst and the blue line with only the standard system
