Composition of Current and Alternative Jet Fuels Nov 3, 2011 Tim Edwards, AFRL Russ White, API.
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Transcript of Composition of Current and Alternative Jet Fuels Nov 3, 2011 Tim Edwards, AFRL Russ White, API.
Composition of Current and Alternative Jet Fuels
Nov 3, 2011
Tim Edwards, AFRLRuss White, API
2DISTRIBUTION STATEMENT A – Unclassified, Unlimited Distribution
Bottom Line Up Front
• Approved and prospective alternative jet
fuels (either 100% or blends) will be
hydrocarbons very similar to current fuels
• Fuels are to be “drop-in” – no handling
changes
• Most notable differences reduce the health
effects of these fuels– Lower aromatics – Lower sulfur
3DISTRIBUTION STATEMENT A – Unclassified, Unlimited Distribution
Current Composition Limits in Jet Fuel Specifications
• Aromatics < 25 vol% by D1319
• Naphthalenes < 3 vol% by D1840 (not naphthalene)
• “Light ends” controlled by flash and T10
• “Heavy ends” controlled by freeze and T90
• Density spec (0.775-0.84) requires cycloparaffins and/or
aromatics
• Impurities indirectly limited by thermal stability
• Sulfur content limited
• Smoke point limits aromatics indirectly (naphthalenes
more directly)
4DISTRIBUTION STATEMENT A – Unclassified, Unlimited Distribution
Aromatics in JP-8
0
200
400
600
800
1000
0 2 4 6 8 10 12 14 16 18 20 22 24 26
PQIS data 2008
Num
ber
of s
ampl
es
Aromatics by D1319, vol %
avg 17.4+/- 2.7 vol%
5DISTRIBUTION STATEMENT A – Unclassified, Unlimited Distribution
Naphthalene Study
• Individual naphthalenes results reported in µg/mL; total naphthalenes in
volume % (convert to µg/mL by multiplying by 1.06x104)
•Large standard deviations in concentrations within fuel classes
•Consistent results between current study and previous World Survey fuels
•Highest naphthalene in jet fuels and F-76, lowest in motor diesel
•Highest total naphthalenes in F-76 diesel, lowest in motor gasoline
FuelNaphthalene
(µg/mL)
1-Methyl naphthalene
(µg/mL)
2-Methyl naphthalene
(µg/mL)
D1840 Total
naphthalenes (volume%)
D6379 Total
naphthalenes (volume %)
Jet 1530 ± 772 1520 ± 495 2360 ± 869 1.15 ± 0.38 1.33 ± 1.49
F-76 1590 ± 599 1690 ± 701 3010 ± 1505 4.05 ± 0.84 5.74 ± 1.21
Motor diesel 357 ± 241 563 ± 467 1050 ± 875 2.61 ± 1.01 3.19 ± 1.48
Motor gasoline 1480 ± 797 467 ± 319 1080 ± 733 0.42 ± 0.21 0.42 ± 0.23
Jet (World Survey) 1580 ± 1037 NA NA 1.23 ± 0.72 1.80 ± 1.00
NA= Not analyzed
6DISTRIBUTION STATEMENT A – Unclassified, Unlimited Distribution
Jet Compositional Space
aromatics
cycloparaffins
n- +
iso-
para
ffins
25% aromatic limit in D1655,D7566
25
50
75
Avg: 53 n/iso, 28 cyclo, 19 aroWorld Survey
• ASTM D2425 currently used
7DISTRIBUTION STATEMENT A – Unclassified, Unlimited Distribution
5 10 15 20 25 30
4597 Jet A
4598 Jet A
4599 Jet A
4600 Jet A
4626 Jet A
4658 Jet AC7
C11
C16
Limited by flash point Limited by freeze point
Jet GC-MS
8DISTRIBUTION STATEMENT A – Unclassified, Unlimited Distribution
GC X GC
naphthalenes
alkyl benzenes
• JP-8 (POSF 4751)• Aromatics separated by class and carbon number
9DISTRIBUTION STATEMENT A – Unclassified, Unlimited Distribution
Baseline Fischer-Tropsch Fuels
n-paraffins
• Form basis of Research Report to support specification
B-52, T-38
C-5, B-2, C-130, F-16, HH-60, T-6, A-10, RQ-4
C-17, B-1, F-15F-22, KC-135R
10DISTRIBUTION STATEMENT A – Unclassified, Unlimited Distribution
Sasol IPK/A Analysis
• Research Report to support specification based on similarity to petroleum jet
11DISTRIBUTION STATEMENT A – Unclassified, Unlimited Distribution
HRJs feedstock independent
C13 C14 C15
C12
C9
C8
C11
C10
jatropha/algae oil
jatropha oil
camelina oil
animal fat
Salicornia oil
F-T
Inte
nsity
(ar
bitr
ary
units
)
Time
12DISTRIBUTION STATEMENT A – Unclassified, Unlimited Distribution
SPK Compositional Space
cyclo-paraffins
iso-paraffins n-pa
raffi
ns
15% cyclo limit in D7566Sasol IPK
Shell SPKS-8
ARA
PSU
cam HRJ
tallow HRJ
Gevo
13DISTRIBUTION STATEMENT A – Unclassified, Unlimited Distribution
Fuels from Woody Biomass
• Focus of DOE Biomass program
• Can yield fuels of atypical composition “Sugars”
Lignin
14DISTRIBUTION STATEMENT A – Unclassified, Unlimited Distribution
Lignocellulosic Biomass
April 21, 2023
“Sugars”
“Pyrolysis Oil”
alcohols jet “alcohol-to-jet”
jet“direct fermentation” or“metabologic engineering”
gasification syn gas jet
Fischer-Tropsch
“SPK”
pyrolysisjet
upgrading
fermentation
catalysis
jet “catalytic renewable jet?”
“pyrolytic renewable
jet?”
15DISTRIBUTION STATEMENT A – Unclassified, Unlimited Distribution
Gevo Public Data
16DISTRIBUTION STATEMENT A – Unclassified, Unlimited Distribution
Summary
• Alternative aviation fuels will remain hydrocarbons,
but…– Specifications will add more composition constraints– Molecular weight range may narrow (but still be ~8-14)– Blend stocks with a small number of HCs may exist– Relative proportion of hydrocarbon classes may shift– Sulfur will decrease, relative to current average of ~700 ppm– Blend stocks with and without aromatics will be seen
• Health benefits of alternative fuels currently not being
given credit in evaluations of “drop-in” fuels
17DISTRIBUTION STATEMENT A – Unclassified, Unlimited Distribution
Turbine Engine Emissions
• AF, NASA, FAA supporting emissions
testing for alternative jet fuels– The “usual” – NOx, CO, UHC, SOx– Particulates to support SAE E31 ARP– VOC, HAPS to develop database
• Significant data on ground (AAFEX etc.)
• Bottom line – alternative jet fuels are
hydrocarbons, most emissions unchanged– Exception – particulates (soot), typically reduced
18DISTRIBUTION STATEMENT A – Unclassified, Unlimited Distribution
18
AFRL Turbine Engine Research Transportable Emissions Lab (TERTEL)
Instrument MeasurementCondensation Particle Counter(TSI 3022A)
Particle Number
Scanning Mobility Particle Sizer (TSI 3936)
Particle Size Distribution(D=4.0 - 570 nm)
Tapered Element Oscillating Microbalance (R&P 1105)
Particle Mass Concentration
FTIR Analyzer (MKS 2030) CO2, CO, NOx, SOx, HC speciesNDIR Analyzer (CA 602P) Diluted Sample CO2
Smoke Sampler & Reflectometer(Photovolt Instruments Inc. 577)
Smoke Number
LECO Carbon Analyzer (RC-412) Elemental/Organic CarbonFID Analyzer (CA 600) Total HydrocarbonsMulti-Angle Absorption Photometer Particle Mass Concentration
19DISTRIBUTION STATEMENT A – Unclassified, Unlimited Distribution
Emissions Collaboration
DC-8
AFRL EmissionsTrailer EPA
Missouri S&T
AEDC, NASA/GRCAerodyne
NASA/LaRC
• Emissions study conducted with multiple partners on modified NASA DC-8 (CFM56) – Jan ’09– Multiple FT fuel blends (Sasol, Shell, 50/50, & 100%)• Data reduction underway but clear PM reductions with FT fuel and blends
20DISTRIBUTION STATEMENT A – Unclassified, Unlimited Distribution
21DISTRIBUTION STATEMENT A – Unclassified, Unlimited Distribution
AAFEX I
22DISTRIBUTION STATEMENT A – Unclassified, Unlimited Distribution
• Higher impact at lower power
– Consistent with previous studies (e.g. T63, CFM56, T701C, TF33)
– Reduce HC aerosols– Reduce soot nuclei
• Increased role of paraffinic species on soot formation at higher power
AAFEX CFM56 Particle Number EI
1.00E+11
1.00E+12
1.00E+13
1.00E+14
1.00E+15
1.00E+16
0% 20% 40% 60% 80% 100%
Parti
cle
Num
ber
EI (
#/kg-f
uel)
Engine Setting
JP-8 R (27 Jan - 48 F) FT1 (28 Jan - 56 F) FT2 (30 Jan - 60 F)
Significantly lower particle number EI with FT fuels
23DISTRIBUTION STATEMENT A – Unclassified, Unlimited Distribution
AAFEX I (cont)
24DISTRIBUTION STATEMENT A – Unclassified, Unlimited Distribution
Ultralow Sulfur Jet Fuel
2009
25DISTRIBUTION STATEMENT A – Unclassified, Unlimited Distribution
Diesel Engine Evaluation with Alternative Fuels
•Similar engine performance (fuel conversion eff.) with JP-8, FT blend & diesel
•Higher engine exhaust temperatures (5-10%) with diesel at higher RPMs
•Slight reductions (5-10%) in engine BHP with JP-8 and FT blend
– Lower fuel density and limits in fuel delivery system
• Impact of JP-8 and FT blend on emissions dependent on engine and condition
•Highly variable particle number data
– Inherent non-continuous combustion in reciprocating engines
•Similar or lower smoke numbers with alt fuels
•Moderate reduction in PM mass
•Mostly lower CO (20-40%) and NOx (10-17%) emissions
– Trends agree with previous measurements in 6.5L diesel
•Technical paper to be included in IASH 2009 proceedings