1. Next Generation OBIGGS: Developments at Phyre Technologies
Santosh Y. Limaye
Phyre Technologies, Inc.
November 2, 2005
Atlantic City, NJ
Presented at International Aircraft Systems Fire Protection Working Group Meeting

2. The Concept Treat the ullage from the fuel tank to create inert gas
Inexpensive catalytic system
Avoid the use of bleed air
This concept resulted from liquid fuel de-oxygenation system development

3. High Heat Sink Fuels: Enable Advanced Propulsion
Fuel Temperature, F
Fuel Temperature, C
Combustor
Endothermic fuels
pyrolytic deposits
Fuel Flow
JP-8
JP-8+225
JP-900
thermal-oxidative
deposits
JP-8+100
600
400
200
300
500
800
1000
1100
900
700
Filamentous
Condensation
Amorphous 2 4 6 8 10 12 14
>1300 F
Deposition is The Significant Challenge for High Heat Sink Fuels
Heat sink relative to JP-8
900 F
550 F
425 F
325 F
JP-8
JP-8+100
JP-8+225
JP-900
Endo JP
Near term
Mid - Term
Higher heat sink capability of fuels will enable several critical aspects of advanced propulsion.
The heat sink capabilities of fuel are limited by the temperature at which fuels form deposits. Typically, these deposits are caused by thermal oxidation of the fuels, a well known phenomenon
Thus, there are several strategies that allow heating the fuels to higher temperatures. These include - -
Increase Thrust-to-weight
enables higher T41
Reduce take-off gross weight
reduce fuel recirculation & ram air HX wt
Improve SFC
enables higher T3 and P3
Reduce component operating temp.
higher heat sink capability
High Heat Sink Fuels Benefits

4. Quick Review of De-Oxygenation System
Fuel Gas
Contactor
Contaminated
Fuel
Inert Gas
De-Oxygenated
Inert Gas + O2
+ Fuel Vapor
Gas Treatment
System
Oxygen free gas
For Recycling
Pump
Separator
Removing dissolved oxygen in fuel prevents premature oxidation; a primary cause of coking.
Dissolved oxygen = cholesterol

5. Mass Transfer Issue Mass Transfer Region O2 Concentration Gradient
Kinetics of sparging processes is limited by mass transfer issues at the gas liquid interface.
Kinetic of membrane based de-oxygenation is limited mass transfer rate through the membrane
Diesel Droplet in N2 Gas
N2 Bubble in Diesel

6. Does it work? - - YES! Fuel O2 = 57.9 ± 5.4 ppm10 20 30 40 50 60
0.5 1
1.5 2
2.5 3
3.5 4
Fuel Flow (lpm) O
Concentration (ppm)
O2 = 5 ppm
Fuel O2 = 57.9 ± 5.4 ppm
N2 flow: 2.5 Liter/Min; lpm
Low dissolved oxygen levels are easily obtained

7. Results from Testing at AFRL
Run75
Run79/81
Baseline JP-8
PADS Deox JP-8 (Catalyst)
Visual inspection of the servo flow divider valve spool and body shows that the deposition from deoxygenated fuel is essentially the same as for additized +100 fuel. Valve hysteresis is somewhat higher for deoxygenated fuel vs additized fuel. The shape of the hysteresis curve with the balloon at the upper right seems to indicate a worn valve.
Run80
Run76
PADS Deox JP-8 (Nitrogen)
JP-8+100
PADS DeOx JP-8 (LN2)

8. OBIGGS

9. OBIGGS Considerations15 10
Hydrocarbon Vapor
Volume Fraction (%)
Dilution with Air
Inert Air Purge 5
Flammability
Region
Critical Dilution with Air 5 10 15 20
Oxygen
Volume Fraction (%)

10. Catalytic Inerting System (CIS): Next Generation OBIGGS Concept
Make up air to consume hydrocarbon
vapor and pressure equalization
Catalytic Gas Treatment System
<10% oxygen + Fuel vapor + CO2 H2O + N2
21% oxygen + Fuel vapor + N2
safety device
Pump
Air + Fuel Vapor
Water
trap
Fuel
PATENT PENDING

11. CIS System Description
Low Temp. air to air
Heat Exchangers
Inlet Oxygen
Sample Port
Reverse Flow Valve
Heat Exchanger & Heaters
Reverse Flow
Valve
Blower
Catalyst Bed,
5” Dia x 4.5”length
Inlet
Size: 12”x12”x 40”
Capacity: 150 CFM
# of passes to 10% O2 : 3
Outlet
Control Unit
Water Drain
Support Systems
Power
Automatic Moisture
Drain Valves
Oxygen Sensors
Optional, High Removal Rate,
Vapor Fuel Control

12. CIS Catalytic Chemistry
Vapor Pressure of Nonane (Jet Fuel)
T C
T K
VP Pa
Atmospheres
-46.8
226.35 1
-26
247.15 10
273.15
100 34
307.15
1,000
80.8
353.95
10,000
150.3
423.45
100,000
Saturated vapor phase of fuel vapor : C9H20 (Nonane)
As per DOT/FAA/AR-04/8 report (page 12), the precise composition is C9.05H18.01
Vapor pressure of Nonane is estimated to be 8000 ppmv at 70F
Stoichiometric Reaction of 8000 ppmv Nonane will consume 112,000 ppmv (or 11.2%) oxygen to provide 70,000 (7%) and 40,000 (4%) ppmv of CO2 and H2O
70F
Stoichiometric Reaction
C9H O N2  9 CO H2O N2

13. Corrected/Uncorrected
Oxygen Removal Rate
Pass #
O2 %
Corrected O2
Ratio
Corrected/Uncorrected
21.00 1
13.82
14.02
1.01 2
9.09
9.45
1.04 3
5.98
6.44
1.08 4
3.94
4.46
1.13
If H2O is removed from the product, additional fresh air is needed to compensate the gas pressure in the reactant.
The corrected O2 column shows new concentration based on fresh addition of air to replace water molecules.
Three passes will ensure reduction of O2 below 10%.

14. CSR Model: Oxygen Depletion Rate For 450 Cu. Ft. Ullage

15. Experimental Schematic
Pump
Moisture trap
Catalyst Downstream Temp.
CDT
Post Catalyst O2 Conc.
Ullage O2 Conc.
Catalyst
Controller for heater
Oxygen Sensor*
Ullage Volume VU
Heater
Flow Rate FR
Catalyst Temp. CT
Fuel Volume VF
Flow Meter
Pressure gage
Fuel Tank
Experimental limitations:
Very small ullage volume
Limited flow rate control
Objective was proof of concept to validate theoretical calculations
Limitations on catalyst volume (smallest 1.2 cc)
Delayed response due to long oxygen sensor lines

16. Initial Results – Experiment #1

17. Conclusion Prototype Development Testing Phase
Benefits
No need for bleed air, eliminate ozone destruction device
Low temperature process
Only power necessary: blower operation
Smaller foot-print, lighter weight, lower cost
Closed loop system
Ability to reduce oxygen level as well as fuel vapor level
Other Concerns Addressed
Use of fuel vapor phase means no sulfur contamination, no corrosion
Instead of purging the fuel vapor, it is consumed in the process, hence no VOC emissions from the tank
Ability to precisely control gas partial pressures
Next Steps
Prototype Development
Testing Phase
Strategic Partnership Development