Trends in Emissions Regulations and · PDF fileTrends in Emissions Regulations and...

Trends in Emissions

Regulations and Technologies

Tim Johnson

[email protected]

University of Wisconsin

ERC – 2017 Symposium

June 15, 2017

mailto:[email protected]

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


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


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


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


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


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


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


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.


Regulations drive technology.

Cummins, Integer Conf 10-16


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”


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


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


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


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)


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


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.

http://www.emissionsanalytics.com/


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


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


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


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


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


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


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


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


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


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


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


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


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


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


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


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


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


CORNING INCORPORATED PROVIDES THIS DOCUMENT FOR

INFORMATIONAL PURPOSES ONLY, AND ANY RISK CONCERNING

THIS INFORMATION IS WITH RECIPIENT. SPECIFICALLY, CORNING

INCORPORATED MAKES NO REPRESENTATIONS, WARRANTIES,

EXPRESS OR IMPLIED CONCERNING THE INFORMATION,

INCLUDING WITHOUT LIMITATION WARRANTIES THAT THE

INFORMATION IS ACCURATE.

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