Post on 06-Mar-2018
Trends in Emissions
Regulations and Technologies
Tim Johnson
JohnsonTV@Corning.com
University of Wisconsin
ERC – 2017 Symposium
June 15, 2017
Environmental Technologies © Corning Incorporated 2
Summary
• Regulations
• European RDE limits finalized, 2.1X for LDD NOx, 1.5X GDI PN
• China 6 finalized. -40% vs. Euro 6 in 2023
• China VI proposed – similar to Euro VI; India also in 2020
• Engine technologies
• Gasoline closing gap with diesel. HEV as good or better than diesel.
• Future direction is xEV
• US HD closing gap with EU this year and will have lower FC. Electrification gaining
interest
• NOx control
• New SCR catalyst durable to 900C. Similar in performance to best today.
• HD low NOx systems tested. Indications down to 20-30 mg/bhp-hr NOx
• DPF regeneration characterized for CSF; SCRF passive regeneration improving
• DOCs dropping temperatures T50~200C; CH4 oxidation catalyst light-off at 220C
• GPFs further characterized
• Fuel impacts on PN
• Takes out PAHs
• Ash to 150,000 miles
Regulations
Environmental Technologies © Corning Incorporated 4
China and EU have conflicting regs versus US. For cold start: Well mixed charges are needed for PM/PN reduction, but stratified
charges are needed for NMOG+NOx reductions. No harmonization.
Conflicting requirements:
• PM comes from cold
engine surfaces and
poorly vaporized fuel• PM is best mitigated by
having a
homogenous mixture
of fuel and air
• NMOG+NOx comes from
a cold catalyst
• NMOG+NOx is best
mitigated by having a
stratified mixture for
very late spark timing
GM, CARB symposium 9-16
Environmental Technologies © Corning Incorporated 5
About 50% NMHC+NOx reductions from US LDDs are needed
to meet the new Tier 3 requirements of 30 mg/mi NMHC+NOx. Running about 90% cycle average deNOx now, need 95%.
Bosch SAE Congress 2016
Note: Euro 6 levels are 144 mg/km NMHC and 128 mg/km NOx
30 mg/km or 38% of Euro 6
Environmental Technologies © Corning Incorporated 6
New Euro 6 LDD NOx is creeping up ahead of the RDE
implementation date. Best LDDs equivalent to gasoline.
Emissions Analytics, BIS RDE Conf 4-17
• Average EF now ~7
• Rising since 2015, back almost to
Euro 5 peaks
• Despite prospect of Real Driving
Emissions
• Growing variability
• Use of thermal management and hot
re-start strategies?
• Beating first phase of RDE in 2017?
• Average Euro 6 diesel 13
times average gasoline car
• But cleanest diesels (5%
percentile) are as clean as the
average gasoline
• Has been the case for almost
2 years
• Not being able to discriminate
within Euro 6 is significant
market failure0.000
0.100
0.200
0.300
0.400
0.500
0.600
14/09/2011 01/04/2012 18/10/2012 06/05/2013 22/11/2013 10/06/2014 27/12/2014 15/07/2015 31/01/2016 18/08/2016 06/03/2017
Rea
l-w
orld
NO
x (g
/km
)
12 per. Mov. Avg. (Diesel Euro 6) 12 per. Mov. Avg. (Gasoline Euro 5/6)
12 per. Mov. Avg. (Diesel Euro 10th Percentile) 12 per. Mov. Avg. (Diesel Euro 6 5th Percentile)
Top 10% E6 LDD
Top 5% E6 LDD
Avg E6 LDD
Avg E6 gasoline
Environmental Technologies © Corning Incorporated 7
Gasoline COmg/km
THCmg/km
NMHCmg/km
NOxmg/km
N2O
mg/kmPM
mg/km
PN#/km
Engines RDE CF Durability
km
CN 6a 700 100 68 60 20 4.5Before
2020/7:
6.0x1012
After
2020/7:
6.0x1011
AllTT
COP
IUC(1)
2020/7:
Monitor
2023/7:
2.1, to be
adjusted(2)
in 2022
160K
CN 6b 500 50 35 35 20 3.0 All 200K
China 6 Regulations
2017 2018 2019 2020 2021 2022 2023
All vehicles, sales &
registration (CN 6a)
All vehicles, sales &
registration (CN 6b)
TT: type test; COP: compliance of production; IUC: in-use compliance
(1) OEMs need to run RDE at TT & IUC. Regulator can check RDE for COP & IUC. (2) Likely adjusted to a value that only system with GPF can pass. CF
for PN & NOx only. Necessary to measure & record CO during RDE test.
CN
6a
/6b
Ga
s/P
MP
NR
DE
RDE compliant
6x1012 #/km 6x1011 #/km
Final CFsMonitoring
Note: BJ-EPB has not given up yet on BJ6 yet – California gaseous emissions levels (July 2018) – no early PN;
BJ will be superseded by CN6 in 2020
Environmental Technologies © Corning Incorporated 8
China and CARB have the only two meaningful EV mandates.
2025: ~20% in China, and ~8% in California and S177 states
• Quotas proposed by the Chinese Ministry of Industry and Information Technology would
require electric cars to account for 8 percent of new-car sales by 2018, and 12 percent by
2020.
• MIIT looking at automotive long term roadmap
– Energy security and promoting industry
– NEV (PHEV and BEV) mandate after credits (proposed)
• 7% in 2020, 20% in 2025, 40% in 2030
– Mandate will give Chinese OEMs opportunity to leapfrog established players on NEV
Estimate of total ZEV sales to meet CARB and the “177 States” ZEV mandate
~8% of CARB
sales in 2025 will
need to be ZEVs
(2% of US)
CARB ACC Review, 1/17
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China VI Heavy-Duty Regulations (Proposal)Proposal released for public comments in Oct. 2016 by MEP
Timing 2020-2021 nationwide. Major cities may implement earlier (early 2018)
Covers HDD, NG, LPG engines & vehicles − Gasoline engines will be covered by separate regulation
Emission
Limits
PM, PN, NOx similar to Euro VI. NTE requirement; 1700 m altitude requirement
Durability Similar to Euro VI. 700k for heaviest vehicles, similar to US 2010 limit
Min. warranty for heaviest vehicle weight class:5yrs/160K km, similar to US- Emissions warranty & recall will be enforced
Testing &
Certification
1. Vehicle-based certification for COP, IUC− Eliminates “dual map” calibrations for emissions cert. & real world fuel economy
− PEMS to be used for real-world compliance; no PN PEMS; 50-100% load
2. Vehicle-based emissions & FC testing using chassis dyno− Cost savings – same test for emissions and fuel consumption
− Reference vehicle test cycle (C-WTVC) defined
− Production & in-use vehicles could be tested over “any reasonable drive cycles”− Eliminates removing engine from in-use vehicle and testing on dyno
Fuel S < 10ppm, available nationwide in 2018
OBD Euro VI EOBD
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In discussion for China VI-b
• Maximum engine-out NOx
– Back-up to urea tampering
• PEMS might include instantaneous NOx (ppm) plus integrated (g/km)
– Instantaneous NOx limit for all vehicle specific powers (0-15 kW/tonne)
– 500 ppm 90th percentile
– Will help set limits for remote testing
• PEMS PN limit CF=2; 10-100% payload
• 2400 m emissions requirement
• OBD monitoring of vanadia temperature, 550C max.
Possible technology impacts of China 6b regs: High altitude requirement
will limit vanadia SCR catalyst. Maximum engine-out NOx limits will require
EGR. Remote OBD will be onerous but could be effective if coupled with
remote sensing in-use testing.
Environmental Technologies © Corning Incorporated 11
Regulations drive technology.
Cummins, Integer Conf 10-16
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CARB HD low-NOx program is proceeding
• Testing continuing at SwRI to show feasibility
– Engine-aged system in process
– Vocational cycle testing is starting
• Looking at implementation in 2023-25
• CARB needs to get an EPA waiver to enforce the regulation
• EPA is waiting for direction, but so far is “proceeding”
Environmental Technologies © Corning Incorporated 13
EV emissions levels are quantified. EV CO2 not much better than a
Prius, except on the coasts. Criteria pollutants are similar to LDDs.
CO2 Criteria Pollutants
Union Concerned Scientists, 2016
Engines
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Despite the aggressive BEV initiatives announced by some
OEMs, hybrids and ICE Stop/Start are expected to dominate
BEV/HEV Adoption by OEM in 2025
M Vehicles*
Source: IHS Powertrain FCST, Feb’17
Note: * Market includes
NA/EU/CH/JP/KR.• Stop/Start becomes the de-facto standard for ICEs by 2025
• Toyota to lead full hybridization with Honda, HMC, Volvo, GM and Ford following
• BMW and Daimler expected to pursue mild hybridization most aggressively
• VW is expected to lead the BEV segment with close to half a million BEVs in 2025
Environmental Technologies © Corning Incorporated 16
ICCT Technology – Cost analysis for 2025 CO2 targetsPass. Cars: ~ $1000 over 2015 level
VVL, Dyn.
Cyl. Deac.
Mild-hybrid (48V)
CO2 Reduction
Engine
friction,
Weight red.,
transmission,
accessories
Stop-start
GDI, EGR,
Atkinson
Incre
men
tal
Veh
icle
Co
st
(2015 $
)
$16 / (%-CO2)
$33 / (%-CO2)
$75 / (%-CO2)
$200 / (%-CO2)
ICCT, March 2017
Reference: 4-cyl. In-line, 3500 lbs
X: Cost consumer will pay for 5
yr pay back period on trading
up every 5 yrs. 12k miles/yr,
$3/gal, 25% OEM margin
X XX
BEV: 75%
CO2 reduction
for $5750
PHEV: -70%
for same cost
Environmental Technologies © Corning Incorporated 17
Mild hybridization is a relatively cheap way to get incremental
CO2 reductions. Diesel and PEV are similar (except EU)
Mid-range ICCT
numbers
$80/%
$50/%
$80/%
$76/% $57/% EU
(tailpipe=0)
Environmental Technologies © Corning Incorporated 18
Some real-world fuel efficiency data shows gasoline closing gap with
diesel. Downsizing increases RDE vs. cert gap. EU diesel RDE gap vs.
cert increasing, worse than gasoline. HEV RDE better than US cert.
EU real world gasoline closing gap with LDD
(2015: 12% FC difference). Downsizing increases EU RDE vs. cert MPG gap.
EU MPG gap real v. cert
US MPG gap real v. cert
Emissions Analytics, Integer Conf 10-16
Environmental Technologies © Corning Incorporated 19
Real world fuel consumption values show gasoline HEVs at
parity in EU with LDD and far ahead of US LDDs.
www.EmissionsAnalytics.com 12/16
EU gasoline HEV highway fuel economy is
close to parity with EU LDDs.US gasoline HEV combined fuel
economy exceeds EU gasoline HEVs
and is much better than US LDDs. US
LDD penetration will be limited.
Environmental Technologies © Corning Incorporated 20
LDD compared to dHEV: -13% CO2 , -20% RDE NOx, -1.3 s
0-100 kph. €1000 upcharge. Room for dHEV cost reduction.
Diesel dHEV
Weight, kg 2100 2200
Engine, liter-kW 3 - 200 3 – 200
Gearbox 8-sp AT 8-sp AT
Motor, kW 60
Battery, Li-ion 2 kW-hr
HEV dropped CO2 13% on WLTP and engine-
out NOx 20% on all cycles
dHEV NOx → Cost
reduction:
1 stage boosting, Internal +
cooled LP EGR, solenoid
injection system, reduced
number of sensors, etc.
IAV, MinNOx 6-16
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US and EU freight trucks are nearly at parity on fuel
consumption. US is improving at 2.5%/yr. EU at 1.7%/yr. Parity ~2021
2.5%/yr
2015: US trucks burned ~5% more fuel than in EU.
Considering 1.7%/yr in EU vs. 2.5%/yr in US, 2017
gap is 3%. Parity in ~2021. VECTO, 19.3 t trucks.
Daimler, Integer 6/16
Daimler:
• Correct for new test route since 2010
(~ 2l/100km higher FC)
• Similar vehicles (4x2, 400–500hp) and
test conditions (traffic etc.)
• Results of all OEMs considered
ICCT, EC Workshop 6/16
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Electric road systems (like catenary) has highest WTW energy
efficiency (77%), which can reduce total long term cost vs.
diesel.
Cumulative costs 2020-2050 are
lowest for electric road system.
Overhead Catenary Projects:
• Swedish 2-yr field trial started
mid-2016. Scania truck.
• Los Angeles ports testing 3 km
road end 2016. Volvo
• Germany looking at test
proposals for 2017-19 tests.
Siemens, Integer, 6/16
NOx Technology
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SCR catalyst shows stable performance after hydrothermal
aging at 900 C / 12 hrsFully Copper-Exchanged High-Silica LTA Zeolites
Si – yellow
O – red
Cu - blue
LTA zeolite w/ Si/Al = 16 & Cu/Al = 0.48 optimum
NO
x C
on
ve
rsio
n (
%)
Temperature (°C)
0.14
0.32
0.48
Cu/Al = 0.65
FreshAged
900 °C, 10% H2O, 12 hrs
[NH3] = [NO] = 500 ppm, 5% O2, 10% H2O, SV= 100 000 h-1
Temperature (°C)
Si/Al = 11
Si/Al = 23
Si/Al = 16
Cu/Al fixed ~ 0.5
Si/Al fixed ~ 16
Time (hrs)
NO
Co
nve
rsio
n (
%)
SO2 = 20 ppm
at 270 °C
Regeneration
at 500 °C / 2 hr
Resistance to desulfation
LTA, Si/Al=16 & Cu/Al=0.48
X
Cu-SSZ-13
Postech, Angewandte
Chemie Communications, 10/16
Environmental Technologies © Corning Incorporated 25
Total system cost and performance needs to be considered
when choosing SCR catalyst type. V needs more PGM for LT
performance (NO2). V more sulfur tolerant, but DOC NO2 diminishes.
Comment: At 200C, 5% NO2 vs. 20% NO2
can drop VSCR efficiency from 65% to 35%.
Cummins 2017-26-0133
DOC performance drops with sulfur exposure.
Although a
sulfated DOC has
little impact on a
desulfated CuZ, a
sulfated DOC can
also impair a
sulfated CuZ CES, SAE HDE symp. 9-16
Environmental Technologies © Corning Incorporated 26
SwRI summarizes perspectives and some results on prototype
HD lo-NOx systems. PNA+ burner+SCRF chosen due to performance
and budget.
System Chosen for Further WorkSwRI Integer Conf 10-16
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A sustainable LT (150C) NOx Reduction (SLTNR) system is
developing. LT SCR catalyst, pre-turbo DOC, urea vaporizer.
Step 1: Find SCR catalyst designs that perform well
at LT. NO2>40% is needed.
Step 2: Make
NO2 under LT
conditions.
Some DOCs
can make 50%
NO2 at 210-
215C. T↓ w/
EGR, but not
enough. Pre-
turbo DOC
needed.
Step 3: urea injection at LT. Use
vaporizor (need <10µm droplets).
Cummins, PNNL, JM SAE WCX 2017
DPF
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DPF regeneration strategy and required ash storage capacity
are key determinates to filter choice.
LT, high NOx/PM HT, low NOx/PM
Two general HD DPF regeneration strategies.
Ash storage capacity
will affect maintenance
interval. Line of sight to
full useful life.Corning, SAE Brazil 8/16
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A new SCR filter design significantly enhances soot burn with
NO2. SCR performance similar.
SCR-DPF components aged 650C for 50 Hrs
Repeated FTP cycle with EGR turned off
NO2/NOx ~ 30%
Average T ~ 265C
The red trace shows the
latest SCRF designs can
enhance passive soot
regeneration with NO2,
resulting in very little
soot build up over 90
FTP cycles. JM, SAE HDE Symp 9/16
Although NO2
make from DOC
goes down with
ash (blue), NOx
conversion is
unchanged (red).
DOC recovers
upon cleaning.
Natural Gas – CH4 oxidation
Environmental Technologies © Corning Incorporated 32
Queens, S. Valley, U. Limerick App. Cat. B: Env. 187 (2016) 408–418
CH4 combustion proceeds through
(a) dissociation & (b) oxidation via PdO
For enhanced activity:
1) Addition of an O2 carrier TiO2
2) Support acidity -Al2O3 or H-ZSM-5
3) Reduced deactivation/sintering CeO2
4) Use of bimetallic catalyst Pt
Testing: Fixed bed reactor, 0.5% CH4, 10% O2, 5% Ne and
84.5% Ar, GHSV = 100K mL/g/h
Bimetallic catalysts on dual component support shows
improved low-T CH4 oxidation
Gasoline
Environmental Technologies © Corning Incorporated 34
Heavier gasoline causes higher PN. Fuel guidelines for RDE
being evaluated.
Heaviest 10% of gasoline will bring tailpipe PN of 1.5
liter TGDI to 30% engineering margin. EO: +67%
RDE-LDV committee, 1-17
https://circabc.europa.eu/sd/a/00ab01b2-4c2c-46a1-88fc-
2334c18f2415/Kick%20off%20RDE4%20EC%20presentation.pdf
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E10 GDI large PAHs 35-135X higher on FTP-75 than for similar PFI pick-up
truck. PM-based PAHs 14X higher..
E10: 35-135X
higher than PFI
UC-Riverside, SAE PF&L, 10/16
GDI pick-up truck PAH emissions for various fuels. GDI
has 35-135X more heavy PAHs than PFI pick-up.
GPF on GDIs
take down PAHs
below detection,
indicating PAHs
are on the GPF
during operation.
MY2016
Spray guided GDI
Calalyzed GPF
CE-CERT, HEI Workshop, 12-16
Other: Gas-phase
PAHs dropped 50-
70% with GPF
Environmental Technologies © Corning Incorporated 36
Particulate emissions (PN and PM) are similar or reduced
using start-stop vs. normal operation for E0 and E20. Another
study: HEV PN up (but simulated on dyno, not HEV engine)
Both PM and PN are lower in FTP
start-stop mode than in normal
mode for E0 and E20. iBu12 has
much higher start-stop particulates
than normal mode. 2014 Malibu.
ORNL, HEI Workshop 12-16
• Engine bench simulation of
D-segment HEV with 50 kW
electrical system, 1.3 kW-hr
battery
• Engine used only 28% of
time during transients and
high load.
• “HEV” on NEDC has 4.6X
PN vs. conventional
operation.
• Caution: Not calibrated nor
optimized for HEV
Environmental Technologies © Corning Incorporated 37
Ash analyzed from high mileage GDI engines
Ford, SAE Int. J. Engines , 9 (2), 2016
Vehicles: 2010 Ford Taurus & 2010 Ford Flex, 3.5L GDI
Aging done using EPA standard road cycle (SRC) to 130k & 150k miles
Key Findings
Ash accumulation: 58 – 61g 0.24 – 0.29 mg/km- Wall ash thickness ~ 12.4 mm
- Almost 20 g (1/3rd) of ash from upstream TWC !
- 50% of ash not related to oil consumption
- Very little direct interaction of the ash with filter wall
Higher density of ash as compared to Diesel- Higher temperatures + lack of soot cake later
Ash layer reduced wall permeability by 75%- Ash layer permeability = 0.025mm2
Ash location Plug Channel
Distribution (%) ~ 40 ~ 60
Ash Density (g/cm3) 0.7 1.6
Ash composition: Ca, P, Zn from oil
Crystallite phases: CaSO4, Fe2O3, Ca10P6O25
Environmental Technologies © Corning Incorporated 38
Two identical cars tested to 100k km on the road with two
different engine oils (2.2X ash content). PN down 75%. Δp up 8%.
5 g ash
on GPFs
Two identical cars
tested with two different
oils tested for ~100k km
on the road with bare
GPFs. Ash loading low
but the same, despite
2.2X ash content. PN
down 75%. Δp up 8%.
Corning, HKPTC 10/16
Environmental Technologies © Corning Incorporated 39
Surface conductivity of catalyst correlated with catalyst
performance
NECC, SAE Int. J. Engines 9(3):2016
Surface electrical conductivity confirmed as key
contributor to catalyst reactions
- Good correlation obtained between electrical
conductivity and light-off performance for CO-NO
and WGS reaction
Surface electric conductivity of powder material
obtained by the EUPS (Extreme Ultraviolet excited
Photoelectron Spectroscopy) method
CO + NO
CO + H2O
Environmental Technologies © Corning Incorporated 40
Summary
• Regulations
• European RDE limits finalized, 2.1X for LDD NOx, 1.5X GDI PN
• China 6 finalized. -40% vs. Euro 6 in 2023
• China VI proposed – similar to Euro VI; India also in 2020
• Engine technologies
• Gasoline closing gap with diesel. HEV as good or better than diesel.
• Future direction is xEV
• US HD closing gap with EU this year and will have lower FC. Electrification gaining
interest
• NOx control
• New SCR catalyst durable to 900C. Similar in performance to best today.
• HD low NOx systems tested. Indications down to 20-30 mg/bhp-hr NOx
• DPF regeneration characterized for CSF; SCRF passive regeneration improving
• DOCs dropping temperatures T50~200C; CH4 oxidation catalyst light-off at 220C
• GPFs further characterized
• Fuel impacts on PN
• Takes out PAHs
• Ash to 150,000 miles
Environmental Technologies © Corning Incorporated 41
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