# Presentation: 816660

## 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

## 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

## High Heat Sink Fuels:Enable Advanced Propulsion

- Heat sink relative to JP-8

- 325 F

- 425 F

- 550 F

- 900 F

- >1300 F

- Near term

- Mid - Term

**High Heat Sink Fuels:****Enable Advanced Propulsion**

- Deposition is The Significant Challenge for High Heat Sink Fuels

**Notes:**
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 - -

## Quick Review of De-Oxygenation System

- Removing dissolved oxygen in fuel prevents premature oxidation; a primary cause of coking.
**  **
_***Dissolved oxygen = cholesterol ***_

## Mass Transfer Issue

**Mass Transfer Issue**

**Mass Transfer Region**

**O****2**** Concentration Gradient**

**Diesel Droplet in N****2**** Gas**

**N****2**** Bubble in Diesel**

**Notes:**
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

## Does it work? - -  YES! 

-  Fuel O2 = 57.9 ± 5.4 ppm
**	**_**N2 flow: 2.5 Liter/Min; lpm**_

**Notes:**
Low dissolved oxygen levels are easily obtained

## Results from Testing at AFRL

|  |  |
| --- | --- |
|  |  |

***Baseline JP-8***

***PADS Deox JP-8 (Catalyst)***

***PADS DeOx JP-8 (LN2)***

***JP-8+100***

**Run75**

**Run80**

**Run79/81**

**Run76**

***PADS Deox JP-8 (******Nitrogen******)***

**Results from Testing at AFRL**

**Notes:**
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.

## OBIGGS

## OBIGGS Considerations

**Flammability**
**Region**

**5**

**10**

**15**

**20**

**5**

**10**

**15**

**Oxygen**
**Volume Fraction (%)**

**Hydrocarbon Vapor**
**Volume Fraction (%)**

- Dilution with Air

- Critical Dilution with Air

- Inert Air Purge

## Catalytic Inerting System (CIS): Next Generation OBIGGS Concept

- Fuel

- Air + Fuel Vapor

- Catalytic Gas Treatment System

- 21% oxygen + Fuel vapor + N2

- <10% oxygen + Fuel vapor + CO2 H2O + N2

- Make up air to consume hydrocarbon
- vapor and pressure equalization

- safety device

- Pump

- Water
- trap

_**PATENT PENDING**_

## CIS System Description 

**Reverse Flow Valve**

**Reverse Flow **
**Valve**

**Low Temp. air to air**
** ****Heat Exchangers**

- Size**:  **_**12”x12”x 40”**_
- Capacity**:  **_**150 CFM**_
- # of passes to 10% O2** : **_**3**_

**Support Systems**

**Automatic Moisture**
**Drain Valves**

**Water Drain**

**Oxygen Sensors**

**Power**

**Control Unit**

**Optional, High Removal Rate,**
** ****Vapor Fuel Control **

**Inlet Oxygen**
**Sample Port**

**Heat Exchanger ****&**** Heaters**

**Catalyst Bed,**
**5” Dia x 4.5”****length**

**Blower**

**Inlet**

**Outlet**

**CIS System Description **

## CIS Catalytic Chemistry 

- 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

| Vapor Pressure of Nonane (Jet Fuel) |  |  |  |
| --- | --- | --- | --- |
| T C | T K | VP Pa | Atmospheres |
| -46.8 | 226.35 |                1 |        0.00001  |
| -26 | 247.15 |               10  |        0.00010  |
| 0 | 273.15 |             100  |        0.00097  |
| 34 | 307.15 |          1,000 |        0.00971  |
| 80.8 | 353.95 |        10,000 |        0.09709  |
| 150.3 | 423.45 |       100,000  |        0.97087  |

**Stoichiometric Reaction**
**C****9****H****20**** + 14O****2**** + 52.67 N****2****  ******** 9 CO****2**** + 10 H****2****O + 52.67 N****2**** **

*.008 @ 70F*

## Oxygen Removal Rate

| Pass # | O2 % | Corrected O2 | Ratio
Corrected/Uncorrected |
| --- | --- | --- | --- |
| 0 | 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%.

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

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

## Experimental Schematic

- Ullage Volume
**V****U**

- Fuel Volume
- VF

*Pump*

- Flow Rate
**F****R**

*Flow Meter*

*Pressure gage*

*Moisture trap*

*Controller for heater*

- Catalyst Temp.
**C****T**

- Catalyst Downstream Temp.
**C****DT**

*Oxygen Sensor********

*Fuel Tank*

*Catalyst*

*Heater*

- Ullage O2 Conc.

- Post Catalyst O2 Conc.

## Initial Results – Experiment #1

## Conclusion

_**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