the outlook on mobile emissions for the 21 century/67531/metadc... · office of heavy vehicle...

OHVT MissionTo conduct, in collaboration with our heavy vehicle industry partners and their suppliers,

a customer-focused national program to research and develop technologies that will enable trucks and other heavy vehicles to be more energy efficient and able to use

alternative fuels while simultaneously reducing emissions.

Presented at the11th CRC On-Road Vehicle Emissions Workshop

San Diego, CAMarch 26-28, 2001

The Outlook on Mobile Emissions for the 21st Century

Dr. James J. Eberhardt, DirectorOffice of Heavy Vehicle Technologies

U.S. Department of Energy

Office of Heavy Vehicle Technologies

Transportation and Urban Air QualityOutlook on Reducing Mobile EmissionsEPA Emissions Standards Alternatives to Carbon-Based FuelsDiesel Engine Emissions Control StrategyFuels ProgressCatalyzed Diesel Particulate FilterDiesel versus Gasoline EmissionsSummary

The Outlook on Mobile Emissions for the 21st Century

Outline


Population and miles traveled continue to increase resulting in increasing congestion and air pollutionAs a result, over 100 million people live in areas not meeting National Ambient Air Quality Standards (EPA, Oct. 1995)

0

20

40

60

80

100

Mill

ions

of s

hort

tons

CO NOX VOC

All Other Sources

TransportationSources

Transportation and Urban Air Quality

Congestion and Criteria Pollutant Emissions Remain National Concerns, Especially In Urban Areas


The last three years have been very good for reducing

mobile emissions.

Outlook on Mobile Emissions


EPA Emissions Standards

February 10, 2000 EPA adopted Tier 2 Emissions Standards which became effective April 10, 2000. (Includes reducing sulfur levels in gasoline to 30 ppm.)

December 2000 EPA adopted heavy-duty diesel engine emissions standards to be phased in 2007-2010.

January 18, 2001 EPA issued rule requiring 80 percent of all on-road diesel fuel to have less than 15 ppm sulfur starting in 2006.


EPA Emissions Standards

Tier 2 Regulations for Light-Duty Vehicles (LDVs):0.07 g/mi NOx and 0.01 g/mi PM; represents 77 to 95% reduction from Tier 1 levelsIncludes all LDVs under 10,000 lbsPhased in 2004-2008

Heavy-Duty Diesel Engine Regulations:0.2 g/bhp-hr NOx and 0.01 g/bhp-hr PM; represents about 90% reduction from 2004 regsPhased in 2007-2010

Heavy-duty regulations include ultra-low sulfur diesel fuel


What Can Be Accomplished By Working Together

Outlook on Mobile Emissions

Environmental Groups(UCS, NRDC, etc.)

Government (DOE,EPA,CARB,SCAQMD)

Industry(Vehicle/Engine Manufacturers,

Fuel Providers, API)

Office of Heavy Vehicle TechnologiesU.S. Highway Fuel Consumption

Since The 1973 Oil Embargo All Of The Increase Has Been Due To Trucks

0

2

4

6

8

10

12

14

1970 1980 1990 2000 2010 2020

Ener

gy U

se -

Mill

ion

Bar

rels

per

Day

Actual

Class 3-8 Trucks

Class 1-2 Trucks(Pickups, Vans, SUVs)

Automobiles

Projected

Sources: EIA Annual Energy Outlook 2000, DOE/EIA-0383(2000), December 1999Transportation Energy Data Book: Edition 20, DOE/ORNL-6959, October 2000


The Transportation Sector Is Almost Totally Dependent on Liquid Carbon-Based Fuels

97%

2.8%

0.2%

Transportation Energy Consumption, 1997

Source: DOE/EIA Monthly Energy Review; July 1998

Electricity

Natural Gas

Petroleum

Creating Transportation

Options for the 21st

Century


1960s Steam (Rankine cycle) engines

1970s Gas turbines Stirling engines

1980s Adiabatic engines Alternative fuels

1990s Hybrids Fuel cells

Transportation Energy Conversion Technology R&D

History of “Promising” Alternatives


Less than $5M in a given year Greater than $5M in a given year Program Terminated

1970 1975 1980 1985 1995 20001990

Rankine Cycle Engine ($24M)

Automotive Gas Turbine ($393M)

EV Battery (>$410M)

Fuel Cell (>$150M)

Hybrid (>$220M)

Automotive Stirling ($142M)

Transportation Energy Conversion Technology R&D


Alternatives to Carbon-based Fuels

-3000-2500-2000-1500-1000-500

0Hy

drog

en

Met

hane

Etha

ne

Prop

ane

Buta

ne

Pent

ane

Hexa

ne

Oct

ane

Nona

ne

Ceta

ne

Enthalpy of Combustion (kcal/mol)

As a chemical storage system, we have no practical substitute for the C-C bond.

Gas LiquidRoom Temp Transition


Energy Density of Fuels

1058990

922

635594

488

270 266

6814

0

200

400

600

800

1,000

1,200

Diesel Gasoline Ethanol CNG (@ 3626 psi)Diesel Fuel LNG CNG(@ 3626 psi)

Compressed Hydrogen

(@ 3626 psi)

Liquid H2MethanolF-TDiesel

Gasoline Ethanol

Thou

sand

Btu

per

ft3

NiMHBattery


0% 10% 20% 30% 40% 50% 70%

Conventional ICE

Compression-Igniton,

Fuel Cell-Stored Hydrogen

Today's Capability

Projected Capability(2004)

Peak Thermal Efficiency (%)

Fuel Cell-Methanol Reformer

Fuel Cell-Stored Hydrogen

Compression-Ignition Direct-Injection ICE

Gas Turbine

Conventional Spark Ignition ICE

Heavy Duty Diesel Engine

60%

Gasoline Direct Injection

Comparison of Energy Conversion Efficiencies


0 20 40 60 80 100

Vehicle Range Limitation -Challenge To Be Overcome By Alternatives

Comparison of Miles Driven (Same Volume of On-Board Fuel)

Diesel Engine-Conv. Diesel Fuel

Diesel Engine-F-T Diesel

Direct Injection Engine- GasolineAdv. NG Engine-CNG (3,600 psi)

Fuel Cell-Hydrogen (3,600 psi)


Understanding the combustion characteristics of new fuels, e.g., 100 percent paraffinic fuels such as Fischer-Tropsch diesel or fuel blendsUnderstanding how to achieve or control homogeneous charge in compression ignition enginesUnderstanding the benefits of multiple injection and real-time combustion controlUnderstanding the fundamentals of exhaust gas recirculation (EGR) and emissionsUnderstanding the effects of variable valve timing and engine boosting technologies on combustion and emissions

The Future of Combustion in Transportation

Combustion Engines Are Still the Most Viable for Future Heavy Vehicles - -

Some Challenges


Increasing Diesel Cycle Engine Efficiency

1930 1940 1950 1960 1970 1980 1990 2000

0.25

0.3

0.35

0.4

0.45

Source: Caterpillar

THER

MA

L EF

FIC

IEN

CY

(%)

YEAR

PRODUCTION

RESEARCH

30

35

40

45

50

55

Efficiency objective reached with DOE assisted R&D

BSF

C (L

B /

HP

-HR

)

ConsentDecree

Outlook on Emissions

from Combustion Engines

for the 21st Century


There is no accountability for poor policy decisions based on emotion and unsupported by scientific evidence or engineering reality.

Scientific ApproachRepeated experimentation, observation, testingMethodical but slow

Proof by assertion! Quick and easy but likely to lead to bad policy or wrong solution

Nouveau Romanticism

Debate Between Scientists/Engineers and Environmental Activists

Can There Be Such A Thing As A Clean Diesel?


YEAR

EPA/CARB 2004 (SOP)

1980 1990 20000

2

4

6

8

10

12

14

16

Source: Cummins, modified by DOE

NO

x (g

m/h

p-hr

)

Part

icul

ates

(gm

/hp-

hr)

1.5

1.0

0.5

NOx

Particulates

Decreasing Diesel Engine Emissions

1987 Models

1988 Models

1991 Models 1994 Models

ConsentDecree


Progress in Reducing Emissions

Integrated systems approachProgress made in all 3 areasPartnerships with leading industry suppliers, truck/auto manufacturing, energy companies, and national labsCross-cutting applications

Fuels

Emission Controls

Engine Combustion

Auto Light Truck Heavy Truck

Office of Heavy Vehicle TechnologiesCatalyzed Soot Filter Removes Diesel PM

• Collected mass reduced by 75%-90%

• No extractable organics on downstream filter

• All soot (elemental) carbon removed

CSF cleans up exhaust

• Number concentration of very smallest particles may increase

• Micro-analysis indicates CSF particlesare not soot carbon and are volatile

• Dilution tunnel affects size distribution• Smallest particles approach size of gas

clusters as dilution increasesEngine out CSF out

1.0E+05

1.0E+06

1.0E+07

1.0E+08

1.0E+09

dN/dlo

gDp

1.0 10.0 100.0 1000.0 Diameter (Dp) in nm

CSF out,17:1

CSF out, 9:1

Engine out, 17:1

All concentrationsnormalized tono dilution

Source: Oak Ridge National Laboratory


Emissions with and without Particulate Filters

Average School Bus Emissions

0.15

1.62

Belo

w D

etec

tion

Lim

it

Belo

w D

etec

tion

Lim

it

0.0

0.5

1.0

1.5

2.0

2.5

3.0

CO NOx/10 HC PM

Emis

sion

s, g

/mile

Control Vehicles, CARB Fuel (150ppm S)Test Vehicles, CARB FuelTest Vehicles, ECD Fuel (<10 ppm S)Test Vehicles, ECD Fuel & DPX Filter


Emissions with and without Particulate Filters

Average Grocery Truck Emissions, CSHVR(1&2)

0.03

0.32

0.00

3

0.01

0.35

0.00

3

Belo

w D

etec

tion

Lim

it

Belo

w D

etec

tion

Lim

it

0.00.10.20.30.40.50.60.70.8

CO/10 NOx/100 HC PM

Emis

sion

s, g

/mile

Control Vehicles, CARB Fuel (150ppmS)Test Vehicles, ECD Fuel (<10ppm S)Test Vehicles, ECD Fuel & DPX FilterTest Vehicles, ECD Fuel & CRT Filter

Office of Heavy Vehicle TechnologiesFuels Progress (steady-state tests)

Low Sulfur Fuel Enables Heavy-Duty Engine PM Control Devices to Meet EPA Proposed Standards

0

.01

.02

.03

.04

.05

3 ppm 30 ppm 150 ppmPM

Em

issi

ons

(g/b

hp-hr)

Proposed Std.

Source: DOE APBFP DECSE Program


Lower Sulfur Fuel Reduces PM Emissions from Current Heavy-Duty Diesel Engines

*100 gasoline cars (equivalent work to a tanker truck) each one complying with EPA Tier 2

0.026

Tanker Truck Emissions

CARB Diesel FuelARCO

EC-Diesel Fuel

No. 2 Diesel Fuel

Sulfur Level, ppm

PM, g

/mile

Continuously Regenerated Particulate Filter Enabled By Low Sulfur Fuel, Reduces PM to Very Low levels

1000

0.807

0.5810.562

Engine Out

100 cars*1.0

0.011 car/Tier 2

Source: NREL, Evaluation of ARCO EC-Diesel in California Buses and Trucks


Engine-OutExhaust Flow

CROSS SECTIONX-X

STEEL CANISTER

INLET EXHAUST

X

X

INSULATION

Schematic of Catalyzed Diesel Particulate Filter

Office of Heavy Vehicle TechnologiesAutomotive Catalytic Converter

Three Way Catalyst (TWC) Design


Mercedes A170 FTP NOx Emissions Using NOx Adsorber and Various Fuel Sulfur Levels

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

Engine Out NOx Adsorber

FTP

NO

x Em

issi

ons

(g/m

i) 3 ppm30 ppm150 ppm

(0.07)

Tier 2 FleetAverage NOx

After 3000 mile equivalent aging with

30 ppm fuel

Source: ORNL; using laboratory reductant system


Comparison of Gasoline and Diesel Vehicle Emissions

00.5

11.5

22.5

33.5

44.5

1970 1975 1980 1985 1990 1995 2000Year

NO

x g/

mile

050100150200250300350400

PM m

g/m

ile

DVECSE Phase 2(3 PPM Sulfur)

Unleaded FuelIntroduced Diesel PM

Diesel NOx

Gasoline SI NOx

Gasoline SI PM SIDI NOx

SIDI PM

On-road Diesel Fuel sulfur drops


Under Tier 2, diesel emissions must be on par with gasoline emissions

Compared to diesel vehicles, mid-1990s data show that gasoline vehicles produce:

More CO, HC, CO2, CH4, benzene, 1,3 butadiene, and ozone-forming reactive organic gases

Less NOx, PM and aldehydes

Experiments have shown that modern diesels can achieve the new Tier 2 emissions standards with state-of-the-art aftertreatment


Both gasoline and diesel catalyst systems are very effective at treating unregulated emissions

0

10

20

30

40

50

60

70

80

90

Formaldehyde Acetaldehyde Benzene 1,3 Butadiene

FTP

Emis

sion

s (m

g/m

i)

CA Dsl, Engine Out(Ad Hoc)*

F- T Dsl, Eng Out(Ad Hoc)*

Diesel Tailpipe(Ford/FEV)

Gasoline Eng Out(VTT)

Gasoline Tailpipe(AQIRP)

*FTP emissions estimated frommodal engine out tests


15 19 25 32 41 52 67 87 111 143 184 237 305 392 505 6490

200,000

400,000

600,000

800,000

1,000,000

1,200,000

1,400,000

Road Load (km/h in gear)

100/490/4

80/470/4

30/2

15/150/4

Idle

Nu m

ber D

e nsi

ty (c

m

)-3

Road Load (km/h in gear)

Particulate Mobility Diameter (nm)

Num

ber D

ensi

ty (c

m-3

)

Report of the UK Particulate Group (Harwell)

Gasoline PM Are Smaller than Diesel PM

We can now measure and compare the size, number, and distribution of gasoline and diesel PM

Gasoline PM

Diesel PM


Most Recent EPA Assessment

At this time there exists no official EPA document detailing the carcinogenicity evidence relating to gasoline particulate matter. ‡

Recent and Ongoing Research

None are available at this time. ‡

EPA Report on Comparing Cancer Risk of Gasoline and Diesel Particulate Matter

On the Carcinogenicity of Gasoline PM...


EPA Report Comparing Cancer Risk of Gasoline and Diesel Particulate Matter

‡Source: Motor Vehicle-Related Air Toxics Study, Technical Support Branch, Emission Planning and Strategies Division, Office of Mobile Sources, Office of Air and Radiation, U.S. Environmental Protection Agency, April 1993.


Objective: to examine potential air quality impacts that would be caused by exhaust emissions from mobile sources fueled by conventional petroleum-based fuels and alternative transportation fuels.A study being performed by:

US Centers for Disease Control and Prevention (CDC); and US National Institute for Occupational Safety and Health (NIOSH)

For: the US Department of Energy/Office of Heavy Vehicle Technology (DOE/OHVT) and National Renewable Energy Laboratory (NREL)

Comparison of Diesel and Gasoline Emissions

In vitro Genotoxic Activities of Diesel and Gasoline Engine Emissions


NIOSH Study

measure genotoxic activities in vitro (in cells in test tubes)

Mutagenic activity; DNA damage; chromosome damage

for diesel and gasoline engine exhaust particulate material (PM2.5)semi-volatile organic compounds (SVOC)

Objective


Agents and assays

Exhaust particulate (PM 2.5) and SVOC from chassis dynamometer-tested gasoline autos and light-duty diesel vehicles: test acetone extracts of PM2.5 and SVOC sorbent resins, and surfactant dispersions of PM2.5.Assays: Salmonella Typh. Strains YG 1024 and 1029 (Ames), with and without S9 activation.Chromosomal damage: Micronucleus induction in V 79 mammalian cellsDNA damage: Single-cell gel electrophoresis in V 79 cells

Office of Heavy Vehicle TechnologiesTest Vehicles

Average Diesel (72oF)1998 Mercedes Benz E3001999 Dodge Ram 25002000 Volkswagen Beetle

Average Gasoline (72oF, 30oF) Black smoker gasoline (72oF)1982 Nissan Maxima 1976 Ford F-1501993 Mercury Sable1994 GMC 1500 White smoker gasoline (72oF)1995 Ford Explorer 1990 Mitsubishi Montero1996 Mazda Millenia

*Test Vehicles Used In Lovelace Study


Diesel and Gasoline Emissions Have Similar Mutagenic Activity per Unit Mass

(Engine Out)

(with Catalytic Converter)Source: Lovelace Research Institute,Preliminary Results


+++Gasoline SVOC

+++Gasoline PM 2.5

Weak?Weak?+Diesel SVOC

Weak?Weak?+Diesel PM 2.5

Chromosomal Damage

DNA DamageMutagenicitySample

SVOC – Semi-Volatile Organic Compounds

bacterial cell mutagenicity (e.g., Ames test)mammalian cell DNA damage in vitro,chromosomal damage in vitro

Summary of Preliminary Results

Multiple-Tier Estimates of Carcinogenic Potential


The Diesel and Gasoline engine exhaust particulate extracts were mutagenic.The SVOC extracts were mutagenic but not as active as their PM2.5 extracts.The Gasoline engine PM2.5 and SVOC extracts were active mammalian cell genotoxicants.The Diesel engine PM2.5 and SVOC extracts were inactive or weakly active.

Interpretation of Preliminary Results


Engine-OutExhaust Flow

CROSS SECTIONX-X

STEEL CANISTER

INLET EXHAUST

X

X

INSULATION

Schematic of Catalyzed Diesel Particulate Filter

Office of Heavy Vehicle TechnologiesAutomotive Catalytic Converter

Three Way Catalyst (TWC) Design


Catalysts can be very effective at treating both regulated and unregulated emissions

Diesel catalysts have historically used lower precious metal loading to prevent sulfate production. Lower sulfur fuel will enable increased catalyst loadings, further improving performance.

Engine Out and Tailpipe Emissions

Engine-out emissions of regulated and unregulated compounds are not indicative of actual vehicle

tailpipe emissions

Is it time to reconsider the design of our automotive

catalytic converter?


Congestion and emissions of criteria pollutants remain national concerns.The past three years have been very good for reducing mobile emissions.EPA has enacted emissions regulations that include requirements for ultra-low sulfur fuels.DOE’s three-pronged diesel engine emissions control strategy has always advocated fuel formulation/quality as being necessary to meet very low emissions without sacrificing engine efficiency. DOE work on advanced petroleum-based fuels shows that low sulfur diesel fuel is critical to the commercial viability of advanced emission control technologies.

Summary

the outlook on mobile emissions for the 21 century/67531/metadc... · office of heavy vehicle...

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