The SULEV Future Awaits
UW ERC 2013 Symposium
June 5-6, 2013
Dr. Joe Kubsh
Manufacturers of Emission Controls Association
www.meca.org
www.dieselretrofit.org
On Wisconsin!
SULEV Future
• Technology Forcing Emissions Regulations
• First Gen. Super Ultra Low Emission Vehicles
and Partial Zero Emission Vehicles
• Today’s SULEVs/PZEVs
• Tomorrow’s Challenges
CA LEV II 120K Mile Tailpipe Standards
(0-8500 lb. GVW; up to 10,000 lb. for MDPV)
PZEV: 150K mile
durability + “zero” evap.
LEV III/Tier 3 2025
fleet average
0.42
0.42
FTP Emissions, g/mi
0.50
0.40
0.02
0.01
0.10
0.010
0.07
0.01
0.055
0.01
0.10
0.090
0.07
0.01
0.10
0.090
0.20
0.21
0.30
0.00
LEV
LEV/LDT2
NMOG
CO/10
ULEV
NOx
SULEV
PM
LEV/LDT2 only can be applied to 4%of the LDT2 fleet
PZEV Vehicles Provide OEMs with
Flexibilities for Meeting California’s ZEV Requirements
% of LDV
sales in CA
(Includes extended
range hybrids)
(CNG, hybrids,
fuel cells)
(150K mi SULEV,
Zero evap.)
14%
10%
11%
12%
Model Year
5 PZEVs =
1 ZEV
SULEV Vehicle Performance Shows
Very Few Catalyst Breakthrough Events
100
90
80
ULEV2
70
60
TP_CONVEFF_HC
SPD
TP_CONVEFF_NOX
50
40
30
20
10
0
0
200
400
600
800
1000
1200
1400
1600
1800
2000
100
Warm-start
Cold-start
90
Precise A/F control
80
SULEV
70
60
TP_CONVEFF_HC
SPEED
TP_CONVEFF_NOX
50
40
30
20
10
0
0
200
400
600
800
1000
1200
1400
1600
1800
2000
Cold-Start Challenges Solved with
Close-Coupled Converters
VS.
Electrically
Heated
Converter
Close-coupled Converters
for Fast Heat-up
Underfloor Converter
for High NOx Efficiency
Higher Geometric Area Coupled with Lower Weight
Provides Emission Performance Benefits
Relative Geometric Surface Area (GSA) or Bulk Density
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
GSA
Bulk
Density
400/6.5
400/4.3
600/3.5
900/2.4 1200/2.0
Cell density in cpsi, wall thickness in
mils
Nissan Sentra-CA SULEV system
Ref: SAE 2000-01-0887
Toyota Prius SULEV Advanced Catalyst System
0.7 liter, metal matrix
UF HC Adsorber
Butterfly Valve & Actuator
0.9 liter, 900 cpsi ceramic
CC TWC
1.1 liter, 600 cpsi ceramic
UF TWC
Ref: SAE 2000-01-2930
Honda Accord SULEV system
Ref: SAE 2000-01-0887
Gasoline Three-way Catalysts Utilize Advanced
Design Strategies to Maximize Cost Effectiveness
Axial
Zoning
Pd is zoned in the front
to give fast HC light-off
Rh is zoned in the back to
protect against catalyst poisons
Zoned oxygen storage
materials to give
optimum performance
Multiple Coating Layers
Pd Catalyst Layer
Rh Catalyst Layer
SUBSTRATE
WALL
New PZEV Catalysts Drop PGM & Improve
Performance with Advanced Catalyst Materials
2006MY
2008MY
Relative PGM
quantity of a car
100%
50%
Relative
Backpressure
100%
55%
Underfloor
2 bricks
Close Coupled
+
Underfloor
Catalyst
Configuration
Source: SAE 2008-01-0812
Gasoline DI Powertrains Gaining Attention
for Fuel Efficiency Gains – Audi 2.0T PZEV
Secondary
Air Injection
ULEV2
600 cpsi
2.3 liter
60 g/ft3
PZEV
900 cpsi
2.5 liter
150 g/ft3
ULEV2 PZEV
40 g/ft3 100 g/ft3
ULEV2
TWC
Upgrade
Lean
Stratified Secondary Fast TWC Premair
Air
Heat-up
Credit
Start
Source: 2007 Aachen Colloquium
Variety of PZEV Strategies in the
U.S. Market
Vehicle
Engine Displacement
PFI or DI
NA or Turbo
AIR or non-AIR
Average Ignition
Setting (obtc)
Engine Speed (rpm)
Lambda
Max Cat Temp (oC)
Vehicle
A
B
C
D
E
A
2.0
DI
Turbo
AIR
B
2.4
PFI
NA
AIR
C
2.0
PFI
NA
non-AIR
D
2.4
DI
NA
non-AIR
E
2.4
PFI
NA
AIR
-20
1150
1.05 (AIR)
670
0
1200
>>1 (AIR)
1000
-7
1500-1700
.95-1
500
-12
1200-1500
.95-1
700
-5
900-1200
>>1 (AIR)
950
Positives
PZEV turbo, low startup engine speed, more accurate fuel control
Extremely fast catalyst light-off, low startup engine speed, less calibration time
Lowest system cost
Split injections enable fast lightoff w/o AIR
Extremely fast catalyst light-off, low startup engine speed, less calibration time
Ref. : SAE 2012-01-1245
Negatives
High system cost/complexity
Cost of AIR, excess fuel used in start-up
High engine speed in first idle
Additional calibration effort
Cost of AIR, excess fuel used in start-up
Direct Ozone Reduction Catalysts Provide Additional
Opportunities for Near-zero Emission Compliance
• Catalyst coatings applied to
radiators/condensors to
destroy ground level ozone
• Takes advantage of large
air flows & breakthrough
catalyst technology
• No negative impact on
radiator performance
• Over 500,000 catalyst
coated radiators produced
for Volvo since late 1999
1/10 SULEV Achieved on Gasoline Vehicle with
Advanced Engine and Emission Controls
Exhaust manifold bypass quick catalyst
lights-off 5 sec sooner
Source: SAE 2009-01-1076
LEV III/Tier 3 Resets the Emissions Performance
Bar for Light-duty Vehicles – Drives Innovation
FTP NMOG+NOx
LEV III Emissions, g/mi
0.120
0.110
0.100
0.090
0.080
0.070
0.060
0.050
0.040
0.030
0.020
0.010
0.000
LDT2s
>2 Million PZEVs Already on the Streets:
Advanced Catalysts
High Cell Density Substrates
“Zero” Evap. Emission Systems
PCs
3 mg/mi PM
phase-in
20172021
0.030 NMOG+NOx
(SULEV or Tier 2, Bin 2)
'15 '16 '17 '18 '19 '20 '21 '22 '23 '24 '25 1 mg/mi LEV III
Light-duty Vehicle Model Year
PM
review
PM phase-in
2025-2028
Tier 3 Euro 6
Start? GDI PN limit (6 X 1011/km)
Note: California has a gasoline sulfur cap of 20 ppm
Combined NMOG+NOx Standard
Provides Additional Flexibility
•
PZEV Vehicle
Evaluations
–
•
4/5 vehicles struggle
with the 10 mg NMOG
standard
Vehicle A(4K) is most
comfortable
SULEV20
–
•
3 of the 5 vehicles get
relief from the 10 mg
NMOG standard
SULEV30
–
–
No problem with
current 4 cylinder
PZEV vehicles
Opportunities to thrift
catalysts
30
NOx FTP Total (wtd. mg/mi)
–
Vehicle A (4k)
Vehicle B
Vehicle C
25
Vehicle D (4k)
20
Vehicle D
15
Vehicle E
10
5
0
0
10
20
nMHC FTP Total (wtd. mg/mi)
Ref. : SAE 2012-01-1245
2012-01-1245
30
U.S. vs. Europe Light-Duty Emission Standards
Gasoline NOx
mg/km
Diesel PM X 10
250
250
300
Diesel NOx
180
250
200
Euro 6
2014
12
12
21
60
80
45
Euro 5
2009
43
43
62
50
50
60
100
80
150
0
Euro 4
2005
U.S. Tier 2,
Bin 5
2007/2009
ARB
SULEV
2015-2025
Euro 5+ (2011) and 6 include 6 X 1011/km particle number limit for diesels;
Euro 6 includes same PN limit for gasoline direct injection engines (with 3 year delay);
Euro 6 PM mass limit uses revised PMP mass protocol
Gasoline Sulfur Degrades Catalyst Performance,
Example Chevy Malibu PZEV Application
2.4 liter,
4 cyl.:
CC+UF
TWCs
Ref.: SAE
2011-01-0300
UF never above UF at 700-750 C NO NOx “creep”
600 C with FTP; during US06;
with 3 ppm S
NOx “creep”
NO NOx “creep”
GMC Denali Advanced Catalyst System Design
Approaches SULEV Emission Performance
6.0L V8
Engine
0.67 L
1.56 L
900 cpsi
ceramic;
150 g/ft3,
Pt/Pd/Rh=1/16/2
600 cpsi
ceramic;
60 g/ft3
Pd/Rh=4/1
0.67 L
1.56 L
CC
UF
Total TWC Catalyst Volume: 4.46 L (0.74 SVR)
[Ref.: SAE 2007-01-1261]
GMC Denali with Advanced TWC System
Showed Sulfur Sensitivity on Aged TWCs
FTP Emissions, mg/mi:
NMHC+NOx:
74 mg/mi
NMHC+NOx:
NMHC+NOx: 55 mg/mi
45 mg/mi
NMHC+NOx: ca. 20 mg/mi
Low Mileage,
17 ppm CARB Phase III
Fully Aged -220h fuel cut, 860-980 C
17 ppm CARB Phase III
Downsized, boosted DI Gasoline Engine
Reaches SULEV with Advanced TWCs
Cadillac CTS V-Series Test Vehicle
6.0L PI V8
3.6L DI V6
+
twin-turbos
1. Lower fuel consumption – 15% lower on FTP, 10% lower
on combined city/highway cycle
2. Equivalent acceleration
3. Optimized cold-start strategy reduces fuel enrichment and
accelerates CC converter heat-up
4. SULEV emissions with full useful life advanced TWCs
in a CC+UF system
Source: Ricardo 2009 Quarter Review
Hydrocarbon Traps Becoming Viable
• Advances in zeolite thermal stability and system calibration
advances offer HC traps as control option for NMOG.
• Use of E85 fuels pose start-up challenges due to excess fuel
100
TWC
Sample Probe
Thermocouple
HEGO
FG
HEGO
18.6 cm
HC Trap Catalysts
80
Base
Gen 2a
Base = 300 + 135 g/ft3
70
Gen 2a = 100 + 100 g/ft
60
3
50
40
30
20
10
0
A
12.4 cm
mg/mile through Bag 1
90
MB2
MB1
B
TP
C
114 cm
NMOG
Ethanol
Emission components
38 cm
TWCs
NMHC
D
13
8
cm
cm
5
1 2 3 4
Ethanal
GPF Effective at Reducing Particle
Emissions/Black Carbon
even at Cold Ambient Temperatures
FTP Particle Emissions
in Bag 1 (Cold-start) and Bag 3 (Hot-start)
Ambient temperature (°C)
stock GDI HOT
COLD
22 GDI post-GPF HOT
COLD
PFI HOT
COLD
stock GDI HOT
COLD
-7 GDI post-GPF HOT
COLD
COLD
PFI HOT
stock GDI HOT
COLD
-18 GDI post-GPF HOT *
COLD *
PFI HOT
10
8
COLD
10
9
10
10
11
10
12
10
13
10
-1
Solid particle number emission rates (particles mi )
(solid particles > 23 nm)
SAE 2013-01-0527
14
10
GPF Vehicle Durability Run Completed
Test Converter Layout
2.0 L Audi TFSI
CC TWC (stock) + UF TWC GPF
CC TWC + UF converter
Stock Catalyst
CC: TWC 1.24L
80g/ft³
> 2X
EU6 PN limit
CAPoC9, 8-12
26
CC: TWC 1.24L
64g/ft³
UF: GPF
10g/ft³
1.68L
Fuel Efficiency Standards Creating Opportunities
for Lean GDI
SAE 2013-01-1299
• Catalyst manufacturers are working with OEMs to optimize
NOx storage catalysts for cost and performance.
• Future U.S. gasoline sulfur levels are an important consideration
in maximizing the benefits of lean gasoline combustion.
The SULEV Future Awaits
• LEV III/Tier 3 resets light-duty emission performance to a
PZEV average by 2025
• LEV III/Tier 3 emissions performance builds on extensive
SULEV/PZEV experience
• High TWC converter efficiency defined by high cell
density substrates, advanced materials, & sophisticated
catalyst design strategies
• Ultra-low sulfur gasoline an important enabler to Tier 3
compliance pathways
• Future challenges include reduced exhaust temperatures
associated with higher engine efficiencies &
particle emissions from direct injection gasoline engines
Back-up Slides
SULEV Systems Include State-of-the-Art
Engine Designs and Emission Control Systems
• Advanced Emission Control
Technologies include:
– Advanced thermally stable,
oxygen storage materials
– In many cases, layered TWC
coating architectures
– In some cases, HC adsorber
functions
– High cell density substrates
– Fast response oxygen
sensors
– In some cases, secondary
air systems
– Thermal management
hardware: air-gap pipes &
low heat capacity manifolds
• Advanced Engine
Technologies include:
– Improved fuel injectors
– Variable valve technology
– Lean start strategy with
spark retard for fast
catalyst heat-up
– Electrically controlled
EGR valve
– Advanced control
algorithms for precise A/F
control
Emission Control Industry Has Long Standing
Relationships with ARB, EPA,
Vehicle and Engine Manufacturers
OEM
OEM
Sourcing Decisions
Made by the OEM
SUBSTRATES
CATALYSTS
Manufacturing Flow
Emission Control Industry
supports more than
65,000 jobs in the U.S.
EXHAUST
SYSTEMS
(includes
sensors,
canning)
EVAP
SYSTEMS
(e.g., carbon
canisters)
Key North American Regulatory Drivers:
California LEV 2
• California LEV 2: fleet ave. NMOG requirements
– Fuel neutral (diesel and gasoline with equivalent standards)
– Light-duty trucks meet same standards as passenger cars
– Low sulfur gasoline (15 ppm S ave., 20 ppm S cap started
in 2012); 15 ppm S cap on diesel
– 4K SFTP standards
– California program adopted by New York,
Massachusetts, Vermont, Maine, Rhode Island,
Connecticut, Pennsylvania, New Jersey, Washington,
Oregon, Maryland, District of Columbia, New Mexico,
Delaware (Arizona has opted out of California
standards; PA, DE, & WA do not include CA ZEV
requirements)
GMC Denali & Ford F-150 Fully Aged,
Advanced Emission Systems FTP Performance –
Near Tier 2, Bin 3 Limits
FTP Emissions, mg/mi
60
55
50
40
34
26
30
20
20
10
32 34 30
10
120K SULEV;
Tier 2, Bin 2
Denali - adv. TWCs,
fully aged
F-150 - adv. TWCs,
fully aged
120K Tier 2, Bin 3
0
NMOG/NMHC
NOx
Denali Results Include Modified Calibration Strategy;
F-150 Results Using Stock Engine Calibration
Cold-start Emission Reductions Facilitated
by Advanced Substrate Design


Open structure creates
cavities (mixing chambers)
in substrate
Perforated foils allow
communication between
channels and reduced
thermal mass
2nd Generation GPFs Focusing on Optimization
Layout
Coating
Pressure drop
Bare
Low
Low catalyst
Amount
Because
no catalyst
Closed Coupled
Engine
Add-on
GPF
Type
TWC
GPF
Closed Coupled
Engine
TWC
Under Floor (UF)
GPF
Closed Coupled
Replace
GPF
Type
Engine
GPF
with
TWC
Catalyzed
type
Engine
TWC
Acceptable
GPF
with
TWC
High catalyst
Optimized by
Amount
catalyst
formulation
100
15%
80
60
20
0
Porosity: 48%
MPS: 12µm
Porosity: 42%
MPS: 14µm
Porosity: 33%
MPS: 18µm
1
1st generation
GPF material
2
2nd generation
GPF material
3
Low
40
10mil/200cpsi
ΔP increasing ratio (%)
GPF size: 118.4 x 127L
Cell structure: 5mil/220cpsi
120
Low
Material strength
140
High
High
160
efficiency
Filtration
⊿P increasing
ratio
100%
100
80%
80
High catalyst
loading
60%
60
40%
40
Low catalyst
loading
20%
20
0%0
Low
10mil/300cpsi
Pore volume
12mil/300cpsi
(cc/L)
Pore volume (cc/L)
SAE 2013-01-0836
High