Impact of Fossil Versus Alternative Fuels on Local Air ......United States. ICAO Colloquium on Aviation Emissions with Exhibition 14 – 16 May 2007 ... 1975 1985 1995 2005 2015 30

ICAO Colloquium on Aviation Emissions with Exhibition 14 – 16 May 2007

Impact of Fossil Versus Alternative Fuels on Local

Air Quality and Climate

Impact of Fossil Versus Alternative Fuels on Local

Air Quality and Climate

Dr. Lourdes Q. Maurice Federal Aviation Administration

United States


OutlineOutline

The Issues & DriversAlternative Fuels BasicsCauses for Caution & OptimismThe Way Ahead


Energy Tops the List of Environmental Concerns

Increasing demandWorries about supply peaks and declineSupply interruptionsGeopolitical instabilityPrice StabilityGovernment regulation toincrease “national” fuelsEnvironmental pressures

Issues Within an Environmental Context

Issues Within an Environmental Context


Supply Stability

Drivers for Commercial Alternative Aviation Fuels

….. And must meet specification for safety

70%63%

TotalImports

U.S. Production

U.S. Consumption

2005

Milli

on b

bl p

er d

ay

1975 1985 1995 2005 2015

30

25

20

15

10

5

0

Price

Demand

Environmental impact


OutlineOutline



Jet Fuel Chemistry 101Jet Fuel Chemistry 101

CH3CH2CH2CH2CH2CH2CH2CH3

C2H5Aromatic – CnH2n-6

Naphthene – CnH2n

Paraffin – CnH2n+2

CH3CHCH2CHCH2CH3

CH3 CH3

Iso-Paraffin – CnH2n+2

Jet Fuel comprises vast array of compoundsJet Fuel comprises vast array of compounds

Ringed compounds related to higher particulate matter (PM)

Ringed compounds related to higher particulate matter (PM)


Average CompositionParaffins 60%Naphthenes 20%Aromatics 20%Sulfur 500 ppm

Broad specifications allow significant variations in compositionJet A (Commercial), JP-8 (Military) very similarSulfur spec limit 3000 ppm; avg~500 ppm

n-C9

n-C10

n-C11n-C12

n-C13 n-C14n-C15

n-C16

C11H21 Sulfur Content, JP-8 1997 Buys

00.

020.

040.

060.

08 0.1

0.12

0.14

0.16

0.18 0.

20.

220.

240.

260.

28 0.3

0.32

0.34

0.36

0.38 0.

4

Sulfur, Mass %

Mill

ion

gallo

ns500 ppm

3000 ppm

Conventional Jet FuelConventional Jet Fuel

Edwards, Harrison & Maurice, AIAA-2001-0498


Drop-in replacements1. Low Sulfur Jet-A

Note: Jet-A or Low Sulfur Jet-A can be derived from conventional oil, tar sands, extra heavy oil, or oil shale

2. Fischer-Tropsch (F-T) FuelsSynthetic jet fuel created from coal, natural gas, or biomass

Truly Alternative Liquid Fuels (NOT a drop-in replacement)3. Bio-Fuels - infinite variety (grass to algae), reusable, low feedstock yield4. Cryogenic Fuels (Hydrogen, methane)

Alcohols

Increasing tank volume and aircraft drag via whetted area

Incr

easi

ng a

ircra

ft w

eigh

t

Potential Alternative Aviation Fuels

Potential Alternative Aviation Fuels


Alternative Fuels Composition and Combustion Products

Alternative Fuels Composition and Combustion Products

Fuel + x1 O2 → x2 H2O + x3 CO2 (complete combustion)Assume sulfur in fuel is fully converted to SO2


Conventional versus F-T Aviation Fuels Composition

Conventional versus F-T Aviation Fuels Composition

0

2

4

6

8

10

12

C7 C8 C9 C10 C11 C12 C13 C14 C15 C16 C17

Carbon Number

Volu

me

%

i+c-paraffinsn-paraffins

aromatics

0

5

10

15

20

25

30

35

C7 C8 C9 C10 C11 C12 C13 C14 C15 C16 C17

Carbon Number

i-paraffinsn-paraffins

Volu

me

%

Petroleum Jet A-1 Syngas-derived F-T Jet Fuel

Moses et al., SwRI-8531, 1997


Less Emissions– ~ 1.6% less CO2 created during fuel combustion– 50% to 90% less particulate matter (PM) (measured)– 100% reduction in SOx– ~ 1% less fuel burn (increased gravimetric energy density)

Fischer-Tropsch FuelsEnvironmental Implications

Fischer-Tropsch FuelsEnvironmental Implications


Particulate matter (PM) impacts health and welfare and contributes to visibility degradationMany U.S. airports in areas that are not compliant with national air quality standards for PMPM also a concern because of potential climate impacts

PM 2.5 Nonattainment

PM is a Growing Concern for Aviation

PM is a Growing Concern for Aviation

Data for 50 Largest U.S. Airports

0

20

40

60

80

100

120

Ozone PM 2.5

Non-attaunment

Attainment


Alternative Aviation Fuels Development Maturity

Alternative Aviation Fuels Development Maturity

Fuel Type100% SASOL F-T (substitute for Jet A (Coal-to-Liquid -CTL))

50% syntroleum F-T (substitute for JP-8 (Gas-to-Liquid- GTL))

Iso Pariffinic Kerosene

Bio (Renewable) fuels

StatusSingle source approvalAll tests completeOEM* approvals 1st quarter 2007*Original Equipment Manufacturer

Second source Final tests fundedResults targeted by mid-year 2007

2008 target 50/50 F-T blend2009 target 100% F-T

Boeing/VirginDoD/NASA projects in progress Challenges with freeze point, growing feedstocks

MaturityLevel


Why We Also Need to Focus on Fuel Production

Why We Also Need to Focus on Fuel Production

GroundExtraction &Movement

Processing / Gasification / Refinement Transportation

CO2, CH4, CO, NOx, SOx, VOC

All per unit energy delivered to tank

Raw Material

Jet Fuel

Energy input per energy delivered to tank

Aircraft Tank

Smoke, CO2, NOx, SOxUHC, PM

Ground to tank

Tank to wake


Relative CO2 Emissions for Various Alternatives

Relative CO2 Emissions for Various Alternatives

Dagget et al., SAE-07ATC-15, 2007


Next Steps: Life-Cycle Analysis

Next Steps: Life-Cycle Analysis

Source-to-Tank Analysis

Analysis examines each part of the fuel production cycle using accepted databases such as the Argonne GREET model

Tank-to-Wake AnalysisUse existing data to estimate:

Greenhouse gas emissions Emissions affecting local air qualityAircraft noise (weight impacts)

Focus is on estimating environmental impacts versus aviation economics

Analysis to use FAA-developed tools (Ref. Panel 2, Prof. Waitz)

Analyses combined to determine impacts on costs, energy use, climate, local air quality, and noise resulting

from alternative aviation fuel use.


OutlineOutline



Alternative Fuels may be Environmentally Friendly

Helps Manage Interdependencies

Enhances Energy Security

Aviation’s May Have Potential as Early Adapter

Sustained High Costs Keep Synthetics Viable

Alternative Aviation Fuels –Reasons for Optimism

Alternative Aviation Fuels –Reasons for Optimism


Do not Underestimate Technical Difficulty

Cannot compromise safety

Easier Transition on the Ground

Difficulty of Predicting Energy Markets

Production environmental drawbacks

Alternative Aviation Fuels –Reasons for Caution

Alternative Aviation Fuels –Reasons for Caution


OutlineOutline



Establish whether we can and should pursue alternative aviation fuels

Establish the net environmental benefits – taking into account potential environmental costs – that would arise from such fuels; and

Identify the framework and policies required to facilitate adoption of alternative fuels

Next StepsNext Steps


Commercial Aviation Alternative Fuels Initiative

Commercial Aviation Alternative Fuels Initiative

AIA, ATA

ACI, FAA

Securing a stable fuel supplyReducing environmental impactsImproving aircraft operationsFurthering research and analysis

Commercial Aviation Industry Consortium Formed to work with DoD/DOE/NASA to pursue alternative fuels for the purpose of:


Alternative Fuels Not Abstract – In Use Today“Drop-In” Synthetic Fuels Feasible Near Term – Tank to Wake Emissions ReductionsNeed to Consider Source to Tank ImpactsRenewable Fuels Offer Longer-Term Potential – Source to Wake Emissions ReductionsNeed to Assess Impacts CarefullyBeen on this Road Before – Let’s Stay the Course

Closing ObservationsClosing Observations

Documents

Impact of Fossil Versus Alternative Fuels on Local Air ......United States. ICAO Colloquium on Aviation Emissions with Exhibition 14 – 16 May 2007 ... 1975 1985 1995 2005 2015 30