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)
0.0
90
0.0
90
0.0
55
0.0
10
0.4
2
0.4
2
0.2
1
0.1
0
0.0
7
0.1
0
0.0
7
0.0
2
0.0
1
0.0
1
0.0
1
0.0
1
0.00
0.10
0.20
0.30
0.40
0.50
LEV LEV/LDT2 ULEV SULEV
NMOG CO/10 NOx PM
FTP Emissions, g/mi
LEV/LDT2 only can be applied to 4%of the LDT2 fleet
PZEV: 150K mile
durability + “zero” evap.
LEV III/Tier 3 2025
fleet average
PZEV Vehicles Provide OEMs with
Flexibilities for Meeting California’s ZEV Requirements
% of LDV
sales in CA
Model Year
10% 11%
12%
14%
(Includes extended
range hybrids)
(CNG, hybrids,
fuel cells)
(150K mi SULEV,
Zero evap.)
5 PZEVs =
1 ZEV
SULEV Vehicle Performance Shows
Very Few Catalyst Breakthrough Events
0
10
20
30
40
50
60
70
80
90
100
0 200 400 600 800 1000 1200 1400 1600 1800 2000
TP_CONVEFF_HC
SPEED
TP_CONVEFF_NOX
0
10
20
30
40
50
60
70
80
90
100
0 200 400 600 800 1000 1200 1400 1600 1800 2000
TP_CONVEFF_HC
SPD
TP_CONVEFF_NOX
ULEV2
SULEV
Cold-start Warm-start
Precise A/F control
Cold-Start Challenges Solved with
Close-Coupled Converters
Close-coupled Converters
for Fast Heat-up
Underfloor Converter
for High NOx Efficiency
VS.
Electrically
Heated
Converter
Higher Geometric Area Coupled with Lower Weight
Provides Emission Performance Benefits
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
400/6.5 400/4.3 600/3.5 900/2.4 1200/2.0
Relative Geometric Surface Area (GSA) or Bulk Density
Cell density in cpsi, wall thickness in
mils
Bulk
Density
GSA
Ref: SAE 2000-01-0887
Nissan Sentra-CA SULEV system
Toyota Prius SULEV Advanced Catalyst System
0.9 liter, 900 cpsi ceramic
CC TWC 1.1 liter, 600 cpsi ceramic
UF TWC
0.7 liter, metal matrix
UF HC Adsorber Butterfly Valve & Actuator
Ref: SAE 2000-01-2930
Ref: SAE 2000-01-0887
Honda Accord SULEV system
Gasoline Three-way Catalysts Utilize Advanced
Design Strategies to Maximize Cost Effectiveness
Zoned oxygen storage
materials to give
optimum performance
Rh is zoned in the back to
protect against catalyst poisons
Pd is zoned in the front
to give fast HC light-off
Axial
Zoning
SUBSTRATE
WALL
Rh Catalyst Layer
Pd Catalyst Layer
Multiple Coating Layers
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%
Catalyst Configuration
Underfloor
2 bricks
Close Coupled +
Underfloor
Source: SAE 2008-01-0812
Gasoline DI Powertrains Gaining Attention
for Fuel Efficiency Gains – Audi 2.0T PZEV
ULEV2 PZEV
600 cpsi 900 cpsi
2.3 liter 2.5 liter
60 g/ft3 150 g/ft3
ULEV2 PZEV
40 g/ft3 100 g/ft3
Secondary
Air Injection
ULEV2 TWC
Upgrade
Secondary
Air
Lean
Stratified
Start
Premair
Credit
Fast TWC
Heat-up
Source: 2007 Aachen Colloquium
Variety of PZEV Strategies in the
U.S. Market Vehicle A B C D E
Engine Displacement 2.0 2.4 2.0 2.4 2.4
PFI or DI DI PFI PFI DI PFI
NA or Turbo Turbo NA NA NA NA
AIR or non-AIR AIR AIR non-AIR non-AIR AIR
Average Ignition
Setting (obtc) -20 0 -7 -12 -5
Engine Speed (rpm) 1150 1200 1500-1700 1200-1500 900-1200
Lambda 1.05 (AIR) >>1 (AIR) .95-1 .95-1 >>1 (AIR)
Max Cat Temp (oC) 670 1000 500 700 950
Vehicle Positives Negatives
A PZEV turbo, low startup engine speed, more accurate fuel control High system cost/complexity
B Extremely fast catalyst light-off, low startup engine speed, less calibration time Cost of AIR, excess fuel used in start-up
C Lowest system cost High engine speed in first idle
D Split injections enable fast lightoff w/o AIR Additional calibration effort
E Extremely fast catalyst light-off, low startup engine speed, less calibration time Cost of AIR, excess fuel used in start-up
Ref. : SAE 2012-01-1245
• 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
Direct Ozone Reduction Catalysts Provide Additional
Opportunities for Near-zero Emission Compliance
1/10 SULEV Achieved on Gasoline Vehicle with
Advanced Engine and Emission Controls
Exhaust manifold by-
pass 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
0.0000.0100.0200.0300.0400.0500.0600.0700.0800.0900.1000.1100.120
'15 '16 '17 '18 '19 '20 '21 '22 '23 '24 '25
FTP NMOG+NOx
LEV III Emissions, g/mi
Light-duty Vehicle Model Year
PCs
0.030 NMOG+NOx (SULEV or Tier 2, Bin 2)
LDT2s
3 mg/mi PM
phase-in
2017-
2021
1 mg/mi LEV III
PM phase-in
2025-2028
>2 Million PZEVs Already on the Streets:
Advanced Catalysts
High Cell Density Substrates
“Zero” Evap. Emission Systems
Note: California has a gasoline sulfur cap of 20 ppm
PM
review
Tier 3
Start?
Euro 6
GDI PN limit (6 X 1011/km)
0
5
10
15
20
25
30
0 10 20 30
nMHC FTP Total (wtd. mg/mi)
NO
x FT
P T
ota
l (w
td. m
g/m
i)
Vehicle A (4k)
Vehicle B
Vehicle C
Vehicle D (4k)
Vehicle D
Vehicle E
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
2012-01-1245 Ref. : SAE 2012-01-1245
U.S. vs. Europe Light-Duty Emission Standards
80
60
60
43
12
250
180
80
43
12
250
50
45 6
2
21
0
50
100
150
200
250
300
Euro 4 Euro 5 Euro 6 U.S. Tier 2,
Bin 5
ARB
SULEV
Gasoline NOx Diesel NOx Diesel PM X 10
2005 2009 2014
2007/2009 2015-2025
mg/km
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
UF never above
600 C with FTP;
NOx “creep”
UF at 700-750 C
during US06;
NO NOx “creep”
NO NOx “creep”
with 3 ppm S
2.4 liter,
4 cyl.:
CC+UF
TWCs Ref.: SAE
2011-01-0300
Engine
CC
1.56 L 0.67 L
0.67 L 1.56 L
UF
900 cpsi
ceramic;
150 g/ft3,
Pt/Pd/Rh=1/16/2
600 cpsi
ceramic;
60 g/ft3
Pd/Rh=4/1
GMC Denali Advanced Catalyst System Design
Approaches SULEV Emission Performance
6.0L V8
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:
Low Mileage,
17 ppm CARB Phase III Fully Aged -220h fuel cut, 860-980 C
17 ppm CARB Phase III
NMHC+NOx: ca. 20 mg/mi
NMHC+NOx:
45 mg/mi
NMHC+NOx:
74 mg/mi
NMHC+NOx:
55 mg/mi
Downsized, boosted DI Gasoline Engine
Reaches SULEV with Advanced TWCs
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
Cadillac CTS V-Series Test Vehicle
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
Sample Probe
ThermocoupleFG
1 2 5
TP
DC
MB2MB1
A
B
3 4
18.6 cm
12.4 cm
114 cm
HEGO
HEGO
8 cm
38 cm
TWCs
HC Trap Catalysts
13 cm
0
10
20
30
40
50
60
70
80
90
100
NMHC NMOG Ethanol Ethanal
Emission components
mg
/mile
th
rou
gh
Bag
1
TWC Base Gen 2a
Base = 300 + 135 g/ft3
Gen 2a = 100 + 100 g/ft3
GPF Effective at Reducing Particle
Emissions/Black Carbon
even at Cold Ambient Temperatures
108
109
1010
1011
1012
1013
1014
Solid particle number emission rates (particles mi-1
)
22
-7
-18
Am
bie
nt
tem
pera
ture
(°C
)
stock GDI HOT COLD
GDI post-GPF HOT COLD
COLDPFI HOT
PFI HOT
GDI post-GPF HOT
stock GDI HOT
COLD
COLD
COLD
stock GDI HOT COLD
PFI HOT COLD
GDI post-GPF HOT * COLD *
FTP Particle Emissions
in Bag 1 (Cold-start) and Bag 3 (Hot-start)
(solid particles > 23 nm)
SAE 2013-01-0527
26
GPF Vehicle Durability Run Completed
2.0 L Audi TFSI
CC TWC (stock) + UF TWC GPF
Stock Catalyst CC: TWC 1.24L 80g/ft³
CAPoC9, 8-12
Test Converter Layout
CC TWC + UF converter
CC: TWC 1.24L 64g/ft³
UF: GPF 1.68L 10g/ft³
EU6 PN limit
> 2X
Fuel Efficiency Standards Creating Opportunities
for Lean GDI
• 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.
SAE 2013-01-1299
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 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
• 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
Emission Control Industry Has Long Standing
Relationships with ARB, EPA,
Vehicle and Engine Manufacturers
OEM
Sourcing Decisions
Made by the OEM
SUBSTRATES CATALYSTS
EXHAUST
SYSTEMS
(includes
sensors,
canning)
OEM
Manufacturing Flow
EVAP
SYSTEMS
(e.g., carbon
canisters)
Emission Control Industry
supports more than
65,000 jobs in the U.S.
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
10
20
26
3234 34
55
30
0
10
20
30
40
50
60
NMOG/NMHC NOx
120K SULEV; Tier 2, Bin 2
Denali - adv. TWCs,fully aged
F-150 - adv. TWCs,fully aged
120K Tier 2, Bin 3
FTP Emissions, mg/mi
Denali Results Include Modified Calibration Strategy;
F-150 Results Using Stock Engine Calibration
Open structure creates
cavities (mixing chambers)
in substrate
Perforated foils allow
communication between
channels and reduced
thermal mass
Cold-start Emission Reductions Facilitated
by Advanced Substrate Design
2nd Generation GPFs Focusing on Optimization
0
20
40
60
80
100
120
140
160
1 2 3
Ma
teri
al s
tre
ng
th
Fil
tra
tio
n e
ffic
ien
cy
Lo
w
H
igh
1st generation
GPF material
2nd generation
GPF material
Porosity: 48%
MPS: 12µm
Porosity: 42%
MPS: 14µm
Porosity: 33%
MPS: 18µm
GPF size: 118.4 x 127L
Cell structure: 5mil/220cpsi
Lo
w
H
igh
15%
0%
20%
40%
60%
80%
100%
Pore volume (cc/L)
⊿P
incr
ea
sin
g r
atio High catalyst
loading
Low catalyst
loading
Low High
12mil/300cpsi
10mil/300cpsi
10mil/200cpsi100
80
60
40
20
0
Pore volume (cc/L)
ΔP
incre
asin
g r
atio (
%)
Layout Coating Pressure drop
Add-on
GPF
Type
Bare
Low catalyst
Amount
Low
Because no catalyst
Replace
GPF
Type
Catalyzed
type
High catalyst
Amount
Acceptable
Optimized by
catalyst
formulation
TWCEngine GPF
Closed Coupled
TWCEngine
Closed Coupled
GPF
Under Floor (UF)
Closed Coupled
EngineGPFwithTWC
TWCEngineGPFwithTWC
SAE 2013-01-0836
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