View
219
Download
0
Category
Preview:
Citation preview
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
Recommended