Impacts of Advanced Combustion, Fuels and Aftertreatment ...

Impacts of Advanced Combustion, Fuels and Aftertreatment Technologies on Diesel PM Emissions and Mobile Source Air Toxics:

A Ten-Year Retrospective

February 11, 2009

Chairman’s Air Pollution Seminar Series

Research Center [email protected]

Managed by UT-Battelle 865-946-1232 for the Department of Energy

California Air Resources Board

Sacramento, CA

John Storey Fuels, Engines, and Emissions

mailto:[email protected]

Acknowledgements

• FEERC team: – Ron Graves (Director), Brian West, Jim Parks,

Sam Lewis, Bruce Bunting, Stuart Daw, Scott Sluder, Robert Wagner, Teresa Barone, Norberto Domingo and many others

• DOE support: Office of Vehicle Technologies – James Eberhardt, Gurpreet Singh, Ken Howden,

Kevin Stork, John Fairbanks

• EPA support: OTAQ – Dennis Johnson and Jim Blubaugh

• CARB – Alberto Ayala for inviting me

2 Managed by UT-Battelle for the Department of Energy Presentation_name

Diesel and light-duty diesel have specific challenges in public, regulatory acceptance

•1970’s-90’s tough for diesel

•GM diesel problems

•“Dump Dirty Diesel” Campaign

•CARB interest in diesel replacement with natural gas

1979 Cadillac Diesel Sedan


•1998+ Government Response to Diesel Issues

•DEER conference

•Consent decree between OEMs, EPA

•Fuel sulfur rule

•EPA releases Diesel PM Toxicity

1981 VW Rabbit Diesel Pickup

Who invented the diesel engine?

• Rudolf Diesel 1858 -1913

• Much more efficient than steam engines of the time

• Original vision – to run on vegetable oils! – biodiesel isn’t such a

new idea

• Died mysteriously on ferry to England 1913


[ l

The path forward…..

• Motivation, background of DOE and diesel

• Approach to lowering PM – Engine Hardware – Diesel Particulate Filters

• Current State-of-the-Art – Putting it all together into today’s vehicle – Retrofit PM control – Ultralow sulfur diesel and Biodiesel

• Future – Modeling Emissions Control Systems – Advanced combustion modes – Link to CO 2 emissions and climate change


Oak Ridge National Laboratory • Began as part of the Manhattan Project

• Nation’s largest multiprogram energy Relevant Facilities laboratory

• World’s first nuclear reactor and now leading producer of medical radioisotopes

• Nation’s largest unclassified scientific computing facility

• Nation’s largest science facility, the $1.4B Spallation Neutron Source

• Nation’s largest concentration of open source materials research


National Transportation Research Center

High Temperature Materials Laboratory

Transportation technology

Storage and Consumption Generation distribution

Internal combustion

Alternative fuels

Hydrogen storage Hybrid and transport Electric

Vehicle

Refining

Hydrogen Batteries & production Power electronics Fuel cells

Transportation system analysis


Chassis dyno lab

Presentation_name

internal

Engine Cells

Chassis Dyno Lab

Analytical Labs

Offsite Projects

Fuels, Engines, & Emissions Research Center…. a comprehensive laboratory for combustion engine technology

• A DOE National User Facility in the NTRC

• Focusing on alternative fuels, advanced combustion, and emission control R&D

• Unique or extraordinary diagnostic and analytical tools for engine/emission control R&D

• R&D from bench-scale to vehicle – Chemical/analytical labs – 9 dynamometer stands: 25-600

hp – Chassis dynamometer – Full-pass engine controls

support research – Emissions analysis with high

resolution of time and species – Non-invasive optical and mass-

spec diagnostics – Modeling & simulation

8 Managed by UT-Battelle for the Department of Energy

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The DOE’s Transportation Agenda

• Energy Security, Energy Efficiency – Energy Data Book and http://www.fueleconomy.gov – Energy Independence and Security Act (EISA, 2007)

• 36 Billion gal/yr of renewable fuels (2022) • Limits to corn-based ethanol • Focus on cellulosic ethanol

• Office of Vehicle Technologies – Light-duty engine efficiency goal: 42% (2007) 45% (2010) – Heavy-duty efficiency goal: 50% (2006); 55% (2013) – Meet applicable emissions

• Office of Biomass Programs – Production via Cellulosic sources (biomass)

• Office of Hydrogen, Fuel cells, and Infrastructure Technologies – Automotive fuel cell emphasis


http://www.fueleconomy.gov

IMI IIINS REIEIIDR

So why bring up the DOE vision?

• DOE saw diesel engines as meeting their goal of energy efficiency and security – Heavy-duty engine efficiency program – Light Truck Clean Diesel program

• Emissions control was the enabling technology for diesel

• 1998. DEER conference in Maine


– Diesel Engine Emissions control Research – Organized by DOE (John Fairbanks) – < 100 attendees

• 2008 DEER conference in Dearborn – > 1300 attendees

http://www1.eere.energy.gov/vehiclesandfuels/resources/proceedings/index.html

DEER conferences are comprehensive

• Industry, academia, National Labs, non-profit – Special session for environmental advocacy

organizations

• Thrusts included health effects – First U.S. discussion of nanoparticles and health

• NOx and PM control sessions

• Now large focus on advanced combustion and energy efficiency


Evolution of Heavy Duty Diesel Engine Emission Control

Source – Pat Flynn, DEER 2000

15

10

5

0


0 0.1 0.25 0.6 1.0

1974 EPA (HC + NOx)

1988 1978 (HC + NOx)

1990

1991 1994

1998

1987 Models Retard Timing Lower IMT Shorten HRR Low Friction

1988 Models Retard Timing Inc. Inj. Press Higher Boost Higher CR

1991 Models Retard Timing Low IMT/High IMP Inc. Inj. Press. Variable Inj. Timing

Particulate [g/(HP-hr)]

2004 (2002)

Cooled EGR

NO

x [g

/(H

P-h

r)]

EPA’s emissions standards require substantial PM and NOx reductions for automotive diesels, too.


0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4

FTP NOx Emissions (g/mi)

FTP

PM

Em

issi

ons

(g/m

i)

5

Bin 8

Tier 1, Through 2003

Tier 2 Standards Phase-in 2004-2009

Current iesel

Technology







0 •

How do diesels work, anyway?

Diesel Engine Gasoline Engine (compression ignition)

(spark ignited)

hot flame region:

nitric oxides +

fuel injector

hot flame region:

nitric oxides

spark plug

Source:Caterpillar, 2003smoke


R:ai I pressure sensor

Fuel tank

High pressure ·= =a-,1......._ .......... _"_

pump

\

ontrol n it

Delivery va lve

!Pumping chamber

Spill port

Plunger

IRoll,er tappet

Fuel line

Edge filter

Injector body

Spring

eedle

Nozzle

Fuel injection - key subsystem of diesel

• Pump-line-nozzle (“ancient”)

• Unit injectors

• Common rail (state of art)

• Piezo (combined with

common rail emerging)

Injector tip

Source: Dieselnet.com


https://Dieselnet.com

Injection pressure being increased to aid emission compliance

One bar=14.5 psi

One Mpa=10 bar • Mechanical unit injector=1000 bar (1981)

• “HEUI” =up to 1450 bar

• Early generation common rail=1350 bar

• Latest piezo common rail=1800 bar

• The future (Bosch and others) 2000 bar = 29,000 psi

• WHY? – Tiny, tiny holes (<200 �m) needed to make a fine

spray, smaller particles – But , then pass ~ 1 gallon/hr through each hole!


TDC

Start of lnjec,ilon

IV:C 2

BOC

C"Ombusti 011

TDC

Crank Arngle

BOC

IVO 1

Sequence of diesel fuel injection and beginning of combustion


NOx PM Trade-off curve has been moving

PM

Em

issi

ons

(g/m

i)

0.16

0.14

0.12

0.10 Tier 1, Through 2003

0.08

0.06

0.04

0.02 Bin 8

Current iesel

Technology

50.00 0.0 0.2 0.4 0.6 0.8

NOx Emissions (g/mi)

1.0 1.2 1.4








Diesel PM control – Diesel Particulate Filters (DPF) and Diesel Oxidation Catalysts (DOC)

• DOCs use precious metal catalyst to burn off organic fraction – Typical PM mass reduction is 30% – Used on heavy-duty pickup trucks in 90’s

• First DPF on a car – 1985 Mercedes 300 for California market (not a success) – Need 700 °C to burn off soot with exhaust O 2

• Electrically-heated DPF’s in early 1990’s

• Early systems used DOC + DPF – NO → NO2, then the NO 2 oxidizes the soot

• Later DPFs use catalytic coating – Catalyst on DPF converts NO to NO 2, NO2 oxidizes soot


Diesel Particulate Filter uses ceramic honeycomb to trap PM


Trapped PM

Cell Plugs

Exhaust (PM, CO, HC) Enter

Ceramic Honeycomb Wall

Exhaust (CO 2, H2O) Out

Fifrter

Inlet Outlet

DPF Assembly can replace muffler

Inlet section with Soot filter Outlet section Pre-catalyst flow distributor substrate with water trap

flow flow

V-band + V-band + V-band + gasket gasket gasket


Figure 14, temperature I regeneration line, winter NYC

100 C: 0 90 ~ 80 Cl) C: Cl) 70 C) Cl) ... 60 .c: --~ 50 rn 40 C: ::::, ... 30 -0

:::l::: 20 0

_,.._ :~:68-

/ .,V

/ /"

/ /

/ /4

/ .~ ,~

~ n

03 M!O j M4 -

10

er◄ 280 290 300 310 320 330 340 350 3E

10% temperature, deg.C

Early DPF field study in 2001 in NYC

Uncontrolled Regeneration

• Occurs when DPF accumulates excess soot

• Excess soot can be lit off during high load (hill, ex-way).

• If engine drops to idle during this burning, exhaust flow too low

• Internal DPF temperatures high enough to melt ceramic.

Source: B. Bunting, DEER 2001


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Trap failure is very rapid, typically

TRAP FAILURE, BUS 6358, 2/26/01

1000 10

TE

MP

ER

AT

UR

E, d

eg.C

900 800 8 700 600 6 trap in C 500 trap out C 400 4 press inhg 300 200 2 100

0 0

4:33

:10

4:38

:10

4:43

:10

4:48

:10

4:53

:10

4:58

:10

5:03

:10

5:08

:10

5:13

:10

5:18

:10

5:23

:10

5:28

:10

5:33

:10

5:38

:10

5:43

:10

5:48

:10

5:53

:10

Source: B. Bunting, DEER 2001TIME OF DAY 25 Managed by UT-Battelle

for the Department of Energy Presentation_name

What we are trying to prevent -Uncontrolled Regeneration

What we are trying to prevent -Uncontrolled Regeneration

Hi Temp - Melting

Temp Gradients - Fracture

Low load operation Excessive soot loading

High load operation ignites soot UNCONTROLLED REGENERATION


Solution: active regeneration controls when the DPF is regenerated

Configuration 1 Soot filter with catalyst

Exhaust Outlet

Diesel injection

Configuration 2 Pre-cat Soot filter with catalyst

Exhaust Outlet

Diesel injection

More of a slow burn than a flame thrower


………..Evolution into a system…

• Gasoline vehicle emissions control evolved into a system – Tailpipe approach with oxidation – early 70’s – Air pumps added, late 70’s – A/F ratio control + fuel injection – 80’s – Now completely tied together

• Diesel engine system – – DPF with Active Regen – EGR for NOx control


Better control of fuel injection

Fuel – the missing link

• DPF development well on its way by 2001 – But PM mass was higher with pump fuel

• Sulfur was the culprit – made sulfate aerosol in the exhaust pipe

• DOE had several large research efforts to address sulfur effects 1999-2002 – DECSE (Diesel Emissions Control- Sulfur Effects) – DVECSE (Diesel Vehicle Emissions Control – SE)

• Result: EPA required 15 ppm S in 2006

• Analogous to tetraethyl lead removal – Driven by concerns for catalytic converter – Lower lead levels in people was a byproduct








- - - .. -.: . ,-

The dirty diesel of the past is giving way to clean diesel technology


2008 Dodge Ram 2500 Pickup meets 2009 standards

ter

clDeNOx / Aclva lilCe - nverter cataly1i!c co

BLUETEC

Presentation name

Clean diesel cars available now

32 Managed by UT-Battelle for the Department of Energy _

VW Jetta TDI

Mercedes E320 Bluetec

High pressure EGR tube

EGR cooler

EGR valve Low pressure EGR tube

DPF

Turbocharger with adjustable guide vanes

Inlet mixing nozzle

VW’s emissions controls a marvel of packaging

Source: Internationales Wiener 33 Managed by UT-Battelle

for the Department of Energy Presentation_nameMotorensymposium 2008

I I

Almost 40% improvement in MPG

2009 Volkswagen Jetta 2009 Volkswagen Jetta

Diesel Vehicle Gasoline Vehicle

New EPA MPG

DIESEL REGULAR GASOLINE

33 24 Combined Combined 29 40 20 29

City Hwy City Hwy

Annual Petroleum

Consumption (1 barrel=42 gallons) 11.9 barrels 14.3 barrels

Source: fueleconomy.gov 34 Managed by UT-Battelle


https://fueleconomy.gov

Diesel fuel then and now…

• 1998: Low sulfur diesel rule in effect, largely for PM control. < 500 ppm S, ~450 ppm true – California: ~150 ppm S due to low aromatics

• 2006: Ultralow sulfur diesel for diesel emissions control < 15 ppm S, ~ 8 ppm true – How? The magic of hydrogen. Result is higher

cetane fuel - good for older engines

• Biodiesel: How does it affect PM emissions? – Generally lower PM mass, higher solubles – Alters behavior of DPF → ULSD ≠ B5 ≠ B20








Diesel PM retrofit

• Diesel oxidation catalysts (DOC) popular – Low cost, “bolt-on” solution – ~30% PM reduction

• Diesel Particulate Filters (DPF) offer best PM removal – Require maintenance, off-vehicle regeneration

• Crankcase emissions filtration – Crankcase breather significant source

• ORNL-EPA project examined both – Field-aged DPF from schoolbus – Crankcase PM mass and size


----•-

ged by UT-Battellee Department of Energy Presentation name

Extensive setup of 1999 Cummins B5.9 was necessary to carry out project

38 Mana for th _

Engine

DPF

Transient Emissions

System

PM and HC go down with DPF E

mis

sion

s (g

/hp.

hr)


0.0020 0.0035 0.0066 0.0055

FTP1 FTP2 FTP3 BP-FTP1

BP-FTP2

DPF-FTP1

DPF-FTP2

CDPF-FTP1

CDPF-FTP2

Test Sequence

PM HC

0.5

0.4

0.3

0.2

0.1

0

• 0 • •

I • I • • • • , ,. •• ,

• 0

• •

Total Particle Number Concentration During FTP Cycles

atio

n3 )

(#/

cm

12000

10000

8000

Downstream of DPF Hot FTP 1 (09/04/08) Hot FTP 1 (09/05/08)

Outdoor Air Concentration

Con

cent

r

6000

4000

Num

ber

2000

0 0 300 600 900 1200

Time for FTP (sec) 40 Managed by UT-Battelle


Unique sampler design imposes no vacuum or pressure on crankcase

• All of PM collected

• �p < 0.5” H 2O observed at inlet of tunnel

• PM as much as 18% of regulated limit

To Roots Blower + Flow Measure

Pressure Measurement

SMPS outlet

HEPA Filter

Twin 70mm Filter Holders


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PM emissions from draft tube significant


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Crankcase Emissions Engine Baseline 2.5e+8 Number-Size

SMPS Distribution

Rated Torque 1400 RPM, 300 ft.lbs

(similar to 100% A on 13 mode)

dN/d

logd

p (#

/cm

3 ) APS 2.0e+8

µg = 114 ± 2 nm Ctot 1.5e+8 = 2.9 x 107 #/cm3

1.0e+8

5.0e+7

Increased Backpressure 2.5e+8

0.0 100 101 102 103 104 105

SMPS dp (nm) APS 2.0e+8

µg = 159 ± 2 nm Ctot = 1.4 x 108 #/cm3

1.5e+8

1.0e+8 Backpressure 280 mbar at rated speed (1400 RPM)

5.0e+7

0.0 101 102 103 104 105

dN/d

logd

p (#

/cm

3 )

43 Managed by UT-Battelle for the Department of Energy dp (nm)

Presentation_name

Findings from Retrofit DPF Study

• Field aged DPF (3+ years in service) as received evaluation – DPF very efficiently removing PM – Clean DPF: higher number concentrations until soot layer

builds

• Crankcase emissions – mostly oil droplets – PM mass emissions = 3 X DPF out emissions – PM size shows significantly larger particles

• Crankcase PM treatment complements DPF retrofit

• Model Year 2007 and beyond closes the crankcase

Presentation at 2009 CRC On-Road Emissions Workshop








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Modeling used extensively to improve combustion efficiency, emissions

46 Managed by U for the Department of Energy Presentation_name

Addressing the fundamental losses of combustion flames

Increased use of computational tools

Catalyst Modeling takes off from 2000 on….

Cross-Cut Lean Exhaust Emissions Reduction Simulations

• Objective to improve ability to simulate advanced emissions controls

• CLEERS (cleers.org ) has annual workshops and working groups for NOx and PM control

• Broad participation from industry, academia, labs

• Past presentations available on the web site – Created and maintained by ORNL


https://cleers.org

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Modeling Extended to Engines, Vehicles

8 16 Soot layer Width7 14

Soo

t Lay

er W

idth

(µm

)

6 Engine-out PM

12

5 10

4 8

3 6

2 4

1 2

0 0 0 1372 2744 4116 5488 6860

Time (s)

Eng

ine-

Out

PM

(mg/

s)

•Modeling the growth of the soot layer in a DPF during a drive cycle Source: ORNL Systems Modeling, 2008•No active regeneration of the filter (DPF)48 Managed by UT-Battelle


[~-----~]







High Efficiency Clean Combustion (HECC)

• HECC includes – Homogeneous Charge Compression Ignition (HCCI)

– Premixed Charge Compression Ignition (PCCI)

– others

• Improve powertrain system efficiency by lowering performance requirements for post-combustion emissions controls.

Objectives of ORNL efforts

• Detailed emissions characterization for understanding combustion regimes and environmental impact.

– Hydrocarbon speciation (MSATs!)

– PM characterization


Exhaust Gas Recirculation (EGR) key to advanced combustion modes

• EGR on most diesel engines since 2002

• How does EGR work? – Lowers NOx by diluting charge (air) with exhaust gas

– lowers peak combustion temperature

– Typically increases PM

• High levels of EGR result in lower NOx and PM


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Engine C

oolant

Shaft W

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HP EGR HXN

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Air H

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EGR%

NO

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r

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EGR %

Motivation – 1999 study with VW TDI engine N

Ox,

PM

g/h

p-hr

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1.0

1.4

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0 •

What is this High Efficiency Clean Combustion?

Diesel Engine Gasoline Engine HCCI Engine

(compression ignition) (spark ignited) (Homogeneous Charge

Compression Ignition)

spark plug

hot flame region:

nitric oxides

Source:Caterpillar, 200354 Managed by UT-Battelle


hot flame region: nitric oxides + smoke

fuel injector

Low temperature combustion

ultra low emissions !!

Images of Conventional and HCCI Source: Caterpillar, DEER Conference, 2002


Conventional Diesel HCCI

PCCI = Pre-mixed charge compression ignition

~ •• • • . _, ,._ ________ _

0.16

Advanced combustion changes the NOx-PM trade-off curve

0.14

0.12

Tier 1, Through 2003 0.10

With 0.08 “advanced”

combustion 0.06

Current iesel

0.04 Technology Bin 8 0.02

Tier 2 Standards Phase-in 2004-2009 50.00

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4

FTP NOx Emissions (g/mi)

FTP

PM

Em

issi

ons

(g/m

i)


--00 1000 1500 2000 2500 3000 3500

02

13

4

5

Steady state modes used with HECC to approximate Light-duty FTP cycle.

• BSFC equivalent to What about HCs and CO? baseline operation.

15.0 • Emissions lower

5.0

10.0

5

Engine Speed (rpm)

BM

EP

(ba

r)

0.0

0.5

1.0

NOx PM Conventional

HECC

Estimated FTP Emissions Index (Normalized)


0

□

■

□

□

■

High EGR = high formaldehyde and acetaldehyde formation.


0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

22.2 34.9 40.2 44.3 46.3 48.8 54.0 56.0

EGR %

DN

PH

Mas

s C

once

ntra

tion

mg/

s

Formaldehyde Acetaldehyde Acrolein

Propionaldehyde Benzaldehyde

11 I I I '-1 I \_ I I

I I I I I I I I I I I

What are Mobile Source Air Toxics (MSATs)?


Mobile Source Air Toxics (MSATs)

Particulate Matter (PM)

Volatile Organics

Semivolatile Organics

Metals Diesel PM

Polycyclic organic Matter (POM)

Formaldehyde

Acetaldehyde

1,3-Butadiene

Acrolein

Benzene

Toluene

Ethylbenzene

Xylene Polycyclic Aromatic

Hydrocarbons (PAHs)

Diesel Exhaust Organic Gases

Array of Analytical Techniques for MSATs

Total PM SOF/insoluble SOF speciation

Dilution PM Filters

Tunnel SMPS Particle Size Distribution

Catalyst


Empore Selective capture of semi-volatiles (C10-C18)

GC/MS speciation

DNPH

Selective capture of carbonyl species

HPLC, UV, ESI/MS separation/speciation

Presentation_name

FTIR

C1-C4 species

Canisters

Light HC species

Preconcentrator, GC/MS speciation

DOC Oxidation of Formaldehyde Not Complete Until ~225ºC

• CO, HC, and formaldehyde 100 oxidation efficiency as a 90 function of catalyst temperature 80

– CO oxidation enables higher 70 oxidation of HCs and formaldehyde

– Formaldehyde oxidation not complete until 225ºC C

onve

rsio

n

60

50

40

30

20 • Engine at 1500 rpm/ 1.0 bar during cool down of catalyst 10

from previous higher load 0

operation 125 150 175 200 225 250

Catalyst Temperature (C)

CO HC Formaldehyde

• Thermal management can enable DOC to be kept at temperature where suitable CO/HC/Formaldehyde oxidation occurs, but…

– What is the efficiency penalty associated with maintaining formaldehyde oxidation vs. CO/HC oxidation?


■ □

■ ■

- ■

■

5

Low catalyst temperature presents challenges for tailpipe aldehydes in PCCI mode

1500 rpm, 1.0 bar

5Conv., Engine Out

3

119ºC

Catalyst Temperature

2E

mis

sion

s In

dex

(g/k

g fu

el)

PCCI, Engine Out PCCI, Catalyst Out

4

Tier 2, Bin 5 formaldehyde regulation 0.24 g/kg fuel 1

02000 rpm, 2.0 bar

Formaldehyde Acetaldehyde5

220ºC

Formaldehyde Acetaldehyde

1500 rpm, 2.6 bar

256ºC

Em

issi

ons

Inde

x (g

/kg

fuel

)

Em

issi

ons

Inde

x (g

/kg

fuel

)

44

33

2

1

0 62 Managed by UT-Battelle

for the Department of Energy Presentation_name Formaldehyde Acetaldehyde

2

1

0

an Union adopting number bas

nvestigating number-based sy

Particle size measurements

• Why measure particle size? – Nanoparticles linked to health effects

– Number of particles may be more important than mass

• Modern engines reduce PM size to reduce mass

• With DPFs, PM mass measurement difficult – Europe

– CARB i

Presentation_name

ed regs

stem as well

Engine out DPF out


• •

r, . \ I • I • .. I

I I

I. dN/d

logd

p (#

/cm

3 ) PCCI PM smaller in size at low load and medium load

8e+7 Conv.: Engine Out PCCI: Engine Out Number s are similar,

but PCCI particles much smaller

dN/d

logd

p (#

/cm

3 )

6e+7

4e+7 23 nm 46 nm

2e+7

8e+7 Conv.: Engine Out PCCI: Engine Out 0

6e+7 1 10 100 1000

dp (nm)

4e+7 Number of particles > 100 nm decreases

2e+7

0 1 10 100 1000

64 Managed by UT-Battelle for the Department of Energy dp (nm) Presentation_name







What does all of this mean for greenhouse gas emissions?

• CO2 directly related to fuel efficiency – Engines have been getting more efficient, but..

– …PM emissions controls reduce efficiency • Backpressure, fuel needed for active regeneration

• N2O and CH4 emissions can be a concern – Catalyst systems can make N 2O

– Advanced combustion can make more CH 4

• 2010 regulations could be paradigm shift – Urea-SCR NOx removal efficiency could allow

higher fuel efficiency


Summary

• Engines, PM control have advanced considerably in ten years

• DPFs close to 99% efficient

• Retrofits showing good durability

• Packaging of systems remains a challenge

• DOE continues to push technology for better efficiency


D

Resources

• DEER presentations – http://www1.eere.energy.gov/vehiclesandfuels/res

ources/proceedings/index.html

• CLEERS – http://cleers.org

• Society of Automotive Engineers – www.sae.org

• Health Effects Institute – 2008 Mobile Source Air Toxics report at

www.healtheffects.org


www.healtheffects.org

www.sae.org

http://cleers.org

http://www1.eere.energy.gov/vehiclesandfuels/res

Extra slides


X-Ray Imaging Scouting Study Approach: Measurements with commercial 3D x-ray• MDXi400 by 3D-XRAY, Ltd on

site NTRC March-May 08 • Rotating platform & X-ray fan

beam give 3D profiles • Used for defect detection in

catalytic monolith production • Examined cracks, thermal

damage, washcoat uniformity, soot & ash DPF deposition

• Responds to CLEERS poll interest in DPF monitoring

D

X


X 10-3

3

2

100 200 300 400 500 600 7001 I

- 16.7g ( 3 g/L) soot

- 17.3g ( 3.1g/L) acclimatized

800 900

distribution in-can

Significant Results (6): Confirmed measurement of DPF soot

• 6-in OD uncoated DPF (in can) • Loaded for 5 hours on

Mercedes 1.7-L engine with ULSD fuel

• Quantitative detection of axial soot loading variations thru can wall

2

1.5

1

0.5

0


Soo

t Loa

ding

(g)

0 0.2 0.4 0.6 0.8

X-ray response (a.u.)

Linear calibration curve

Significant Results (7): Also confirmed ability to image details of DPF thermal


damage• 150mm DPF in can

• Thermal damage (by OEM) induced near exit

• Expect to be highly useful for model/OBD validation

Presentation_name

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