Use of Neat Alcohol Fuels and Fuel Blends in

Transportation

USDA Teleseminar—November 30, 2010

Matthew BrusstarAdvanced Technology DivisionOffice of Transportation and Air Quality

U.S. Environmental Protection Agency

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2

Oil Production: Hitting a Wall?

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The High Cost of Transportation

U.S. Trade Balance – Goods: 1960-2005

Climate Change: A Gathering Storm

SOURCE: 2008 Draft Technical Support Document on Climate Change (EPAHQOAR-2008-0318-0082)

• Toward the end of the 21st century, assuming moderate emissions growth, the United States will be much warmer and dryer.

• All economic sectors can be expected to participate in GHG reduction strategies, led by transportation

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Historic CO2 ReductionsEPA GHG Regulations for Light-Duty Transportation

Source: U.S. EPA Report 420-F-10051

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Growing volumes of EthanolProjected Ethanol Volumes under RFS2

Source: U.S. EPA

Source: U. S. EPA Report 420-R-100066

Upstream GHG EmissionsNot all ethanol is created equal…

Source: U.S. EPA

Source: U. S. EPA Report 420-R-100067

Primary Biomass-to-Alcohol Fuel Conversion Pathways

Feedstock Types

Energy cropsCrop waste

WoodForest residue

MSWAlgae

Thermochemical (gasification)

Feedstock economics,

logistics& sustainability

Biochemical (ethanol)

Syngas

Electricity

Feedstock-specificpreparation/feed

Enzymatic hydrolysis

Fermentation

Distillation

Fuels

Ethanol

Methanol

Fuel Transport,Distribution and

End Use

Clean H2

Gasifier• Entrained Flow• Fluidized Bed• Fixed/Moving Bed

Fuel Conversion Technology

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Powertrain Technology• Advanced Transmissions• Hydraulic Hybrid•Electric Hybrid

Powertrain Technology• Advanced Transmissions• Hydraulic Hybrid•Electric Hybrid

Efficient Options for Alcohol End Use

Reducing Greenhouse Gases and Petroleum Consumption

Engine Technology

•Dedicated Alcohol SI

•Flex-Fuel Miller Cycle

•Glow-Plug Assisted CI

•HCCI

•Exhaust Heat Recovery

•Fuel Cells

Engine Technology

•Dedicated Alcohol SI

•Flex-Fuel Miller Cycle

•Glow-Plug Assisted CI

•HCCI

•Exhaust Heat Recovery

•Fuel Cells

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EPA’s Advanced Technology Division: What We Do

Bringing together light- and medium-duty engine technologies and advanced hybrids Joint development with industry

through CRADAs Vehicle demonstration partnerships

Center of excellence for Hydraulic Hybrid Vehicles Advanced hybrid technology: >2X fuel economy at low

cost Series hybrids enable unique

high-efficiency engines ATD is putting advanced

engines into “real world” Hydraulic Hybrid vehicledemonstrations 10

EPA’s Alternative Fuels Engine Program

Economical, High-Efficiency Engine Technologies Supports national policy/renewable fuel

initiatives Vehicle demonstration program

High efficiency hybrid (hydraulic) Heavy-duty Class 6 delivery truck Captive fleet

High efficiency engine program (neat alcohol fuels and blends with gasoline)

Ethanol or Methanol engines with high efficiency (>40% peak)

Lends itself to exhaust thermal energy recovery in the form of chemical and mechanical energy

Combined system yields fuel cell efficiency (>55% peak) at a significantly lower cost

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Combustion PropertiesNeat Methanol and Ethanol—Efficiency

Advantages

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5

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40

45

50

0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5

Fuel-Air Equiv Ratio

Lam

inar

Bu

rnin

g V

elo

city

(cm

/s)

Gasoline

Ethanol

Methanol

Octane Number

Heat of Vaporization

(RON) (kJ/kg)

Methanol 105-110 1103

Ethanol 105-110 840

Gasoline 91-99 350

.

Burning Velocity = rate of fuel heat release in a spark engineFaster burn velocity enables more dilution, less throttling

Octane = knock resistanceEnables high compression ratio

Heat of Vaporization = charge coolingReduces compression work

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0

2

4

6

8

10

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0 20 40 60 80 100

% Alcohol Blend

RV

P (

psi

)

MethanolEthanol

0.4

0.5

0.6

0.7

0.8

0.9

1

0 20 40 60 80 100

% Alcohol Blend

En

erg

y D

ens

ity

*

MethanolEthanol

Properties of Alcohol Fuel BlendsBlends with Gasoline

Energy density = energy per gallon of fuel, relative to gasolineHigher injector flow requiredEngine improvements can compensate for as much as 25-30% loss in energy density (see box above)

RVP = vapor pressure; measure of fuel volatilityMajor factor in evaporative emissions and cold starting

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Engine DescriptionLight-duty and Medium-duty test programs

Base Engine Volkwagen TDI International VT-275

Number of Cylinders Four (Inline 4) Six (V6)

Displacement 1.9 liters 4.5 liters

Bore x Stroke 79.5mm x 95.5mm 95mm x 105mm

Compression Ratio 19.5:1 16.3:1

Power rating (base) 81 kW@4150 rpm 130 kW @2600 rpm

Valvetrain 2 valve/cyl, SOHC 4 valve/cylinder, OHV

Injection System PFI, 1 per cyl PFI, 2 per cyl

Fuel Type E10-E100, M10-M100 E85, M85

Ignition System Spark Ignition Spark Ignition

Air Induction System Single stage VGT Twin single-stage VGT

ECM EPA prototype controller Pre-production controller

Exhaust Aftertreatment Ford FFV 2-stage, three-way catalyst

Three-way catalyst, custom formulation

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Modifications to Base EngineRetrofit or redesign?

Part Modification

Cylinder Head Space for DI injector machined for spark plug

Intake Manifold Machined to accept PFI fuel system

Spark Ignition System Higher energy ignition system, combined with cold spark plug rating

Fuel System Expensive DI system replaced with a high-flow PFI system

Turbocharger Possible change

Aftercooler Higher capacity

EGR system Low-pressure EGR system with cooler

Sensors/Actuators HEGO, fuel pressure

Aftertreatment Replace diesel aftertreatment with three-way catalyst

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Engine Efficiency: 1.9L EngineOver 25% better than best gasoline engines

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42

2

4

6

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12

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500 10001500200025003000350040004500

BM

EP

(b

ar)

RPM

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40

2

4

6

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500 1000 1500 2000 2500 3000 3500 4000 4500

BM

EP

(b

ar)

RPM

• M100 Brake Efficiency• Over 42% peak; better than

baseline diesel

• Broad range over 40%

• E100 Brake Efficiency• Peak over 41%

• Diesel-like efficiency

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Engine Efficiency with Alcohol Blends

Preserving high efficiency with less alcohol

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4 6 8 10 12 14 16 18

Bra

ke E

ffic

ien

cy (

%)

BMEP (bar)

M100

M95

M85

M65

M50

Dilute limitSpark knock limit

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24

28

32

36

40

44

48

4 6 8 10 12 14 16 18

Bra

ke E

ffic

ien

cy (

%)

BMEP (bar)

E100

E85

E65

E30

E10

• Methanol Blends• Increasing efficiency with

higher methanol content

• 38% peak efficiency with M50

• Ethanol blends• Highest efficiency with neat

blends

• Peak efficiency with E30 exceeds best gasoline engines

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Engine Efficiency: E30 BlendEfficiency enhancement using a mid-level

blend

1014

1822

222626

3030

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0

2

4

6

8

10

12

500 1000 1500 2000 2500 3000 3500 4000

BM

EP

(b

ar)

RPM

• E30 (30% ethanol)• High efficiency over a broad

range

• Demonstrates efficiency benefits of dedicated fuel vehicles, even with as little as 30% alcohol

• High-load efficiency gain exceeds loss in fuel energy density

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Advanced Hybrids: Opportunities for High-

Efficiency Engines Advanced Hybrid engine characteristics

High peak efficiency, wide range of efficient power: less need for low-load efficiency

High power density Low cost

Series Hybrids advantages Narrower load-speed

envelope Less aggressive transients,

more load averaging No low-power operation

Mid-size car example

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Medium-Duty (4.5L) E85 map

Hydraulic HybridOperating Line

140 kW

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Brake Efficiency: %

In-Vehicle Results: Dedicated E85 Engine,

Hydraulic HybridMedium-duty delivery truck applicationUses cooled EGR, cycle optimized for higher octane fuelNo bottoming cycle

Minimum engine power

(50-55 kW)

Peak Eff~41%

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Medium-Duty M85/M100 map

Hydraulic HybridOperating Line

140 kW

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Remaining Technical Challenges

Proving the concept out in the field Durability

Fuel system Intake valve seats Cylinder liners and piston rings Ignition system Wear surfaces (effect of oil dilution)

Hot- and cold-weather performance Spark authority at high ambient temperature Cold starting at very low temperatures

Ultra-low tailpipe emissions Demonstrating scaleability to larger-

displacement engines23

Technology Demonstration Opportunities

E85 engine on Hydraulic Hybrid UPS truck Demonstrating roughly 75%

improvement in diesel-equivalent fuel economy

Around 15% better actual miles-per-gallon of fuel than the baseline diesel truck

Engine is demonstrating around 5% better fuel efficiency compared to the diesel

Road demonstration Current plans are to run package

delivery routes starting March/April 2011

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Recoverable Energy from ICE’s

Peak Thermal Efficiencies Spark ignition ~ 34 - 38% BTE Compression Ignition ~ 38 - 42% BTE

Approximate Proportions of Energy from a CI Engine

EngineFuel Energy in

100 kW Shaft Power 38-42 kW

Exhaust Power 30-32 kW

Power to Coolant 28 - 30 kW

Radiator Advantage obtained using adiabatic coatings/insulation

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Exhaust Heat Recovery Systems

Enabled by load-averaging with series hybrids Engine + reformer achieves brake efficiency of 55-

60% Recovers exhaust energy in two forms:

Chemical: superheats methanol under high pressure and dissociates it into H2 and CO, which is burned in the engine

Endothermic dissociation reaction increases the LHV of the fuel by ~ 19.5%

Reaction: CH3OH ---> 2H2 + CO

Energy Balance: 638.1 ---> 2(239.8) + 282.8 kJ/mol

762.4/638.1 => +19.5%

Mechanical: expands the reformed H2 and CO prior to injection in the engine, providing useful shaft work

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Brake Thermal Efficiency with Exhaust Heat Recovery

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1500 2000 2500 3000 3500Engine Speed (RPM)

Bra

ke T

her

mal

Eff

icie

ncy

(%

)

Engine OnlyEngine + HyTEC

Modeling projections based on results of component-level testing of the reforming catalyst and fuel/exhaust heat exchanger

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Choices for the Future…Creating opportunities for dedicated fuel

vehicles

U.S. is striving for dramatic petroleum consumption and GHG reductions in transportation to 2016 and beyond Light-duty and heavy-duty standards Renewable fuel standard (RFS2)

EPA is developing unique high efficiency alcohol engines, enabled by series hybrid technology Opportunities for dedicated alcohol with exhaust

heat recovery Technology demonstrations in captive fleet

applications28

THANK YOU!!!

For more information:Contact: Matthew Brusstar, U.S. EPAE-mail: brusstar.matt@epa.govWeb: http://www.epa.gov/otaq/technology

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