TECHNOLOGY AREA(S): Materials/Processes

ACQUISITION PROGRAM: PMS 312 In-Service Aircraft Program Office, PMS 378/379 Future Aircraft Carriers Program Offices

OBJECTIVE: Mitigate the adverse impact of the presence of copper in Jet Propellant 5 (JP-5) fuel by preventing copper contamination or removing copper that has leached into the fuel.

DESCRIPTION: Copper Nickel (CuNi) pipe is used in JP-5 fuel lines on Aircraft Carriers (CVNs).  Typically, supply ships also have copper piping (though fuel residence time and amount of piping is small compared to a CVN) hence the infrastructure may supply JP-5 fuel with a copper content.  This has allowed a condition where copper contaminates the JP-5 fuel.  The presence of copper in hydrocarbon fuels impacts jet engine performance.  Copper contamination has been observed on the CVN 68 Class Aircraft Carriers.  Copper in JP-5 fuel exists both as particulate and dissolved contaminant.  Replacing CuNi piping on aircraft carriers is both impracticable and expensive.  Presently, no onboard mitigation systems exist to remove copper contamination in JP-5 fuel.  There is a need to create an affordable shipboard method to prevent or remove copper contamination in JP-5 fuel or to prevent copper from adversely affecting aircraft engines.  Joint Strike Fighter programs have a strong interest as the presence of copper in JP-5 fuel creates maintenance and repair issues, such as coking, for aircraft engines as well as impairs performance capability.  Copper contamination in JP-5 fuels can be as high as 1,000 parts per billion (ppb).  Copper contamination prevention or removal methods must limit or reduce (respectively) the copper concentration in JP-5 fuel to 10ppb or less.  Per the American Society for Testing and Materials (ASTM) D3241, copper contamination mitigation methods must meet thermal oxidation stability standards for aircraft (<3 on the unitless color scale Visual Tube Rate (VTR), <85nm Electron Transfer Reaction (ETR) (ellipsometric), <25mm/Hg at 260°C).

Soluble metal chelant additives have been used as means of counteracting the catalytic effects of dissolved copper in fuels.  However, no methods have proven effective for the flow and temperature requirements typical for military aircraft fuel systems.

The JP-5 system is comprised of a network of piping connecting subsystems with pumps, valves, centrifugal purifiers and/or filter separators to ultimately deliver aircraft quality fuel to the refueling nozzle.  Any material and/or technique developed aimed at reducing copper must be applicable to the JP-5 system and subsystems from fuel storage to the system interface with the aircraft.  Furthermore, any material and/or technique developed shall not affect JP-5 fuel properties or aircraft performance and shall not cause a reduction in fuel flow or impact JP-5 operations.  The new prevention, removal or mitigation process(es) shall achieve thermal oxidation stability standards for aircraft (<3 VTR (visual), <85nm ETR (ellipsometric), <25mm/Hg at 260°C).  An effective process would aid the Navy to achieve the mission performance requirements for its aircraft.  As aircraft engine maintenance cost due to the presence of copper contamination in JP-5 fuels is projected to be $1B annually for the fleet, technology to mitigate copper contamination promises potential cost savings to the Navy.  Reducing Maintenance Cost for aircraft engines is addressed through avoidance of installation of a more expensive redesign JP-5 piping system.  Reducing Operating and Maintenance Costs is addressed by reducing the adverse effects of copper contamination, such as coking, in aircraft engines.  Reducing Production Cost Need is addressed through avoidance of aircraft engine redesign that would be capable of meeting mission requirements despite the presence of copper in JP-5 fuel greater than 10ppb.

PHASE I: Develop a concept for a copper contamination prevention, filtering, or mitigating process(es) that demonstrates how the process(es) will be implemented; and present cost estimates for the process(es).  Establish feasibility by material testing and/or through analytical modeling.  Provide a Phase II initial proposal that addresses technical risk reduction and provides performance goals and key technical milestones.  Provide notional shipboard implementation such as how the solution will work in existing distribution systems and restricted volumes and accommodate high flow rates.  The Phase I Option should include the initial specifications and capabilities for the prototype process(es) to be developed in Phase II. Develop a Phase II plan.

PHASE II: Based on the results of Phase I and the Phase II Statement of Work (SOW), develop a prototype process for evaluation and delivery.  Evaluate the prototype to determine its capability in meeting the performance goals defined in the Phase II SOW and the Navy requirements for the copper leakage prevention, filtration, and/or mitigation.  Demonstrate process performance through prototype evaluation and testing over the required range of parameters including numerous deployment cycles to verify test results.  Use evaluation results to refine the prototype into an initial design that will meet Navy requirements.  Prepare a Phase III development plan to transition the technology to Navy use.

PHASE III DUAL USE APPLICATIONS: Support the Navy in transitioning the technology for Navy use.  Develop a copper contamination, prevention, and/or filtration device and/or technique according to the Phase II SOW for evaluation to determine its effectiveness in an operationally relevant environment.  Support the Navy for test and validation to certify and qualify the system for Navy use.  The process has the potential to transition onto CVN, Landing Helicopter Dock (LHD), Landing Helicopter Assault (LHA), and Landing Platform Dock (LPD) platforms.

If successfully demonstrated, there may be a commercial market for a fuel contaminant reduction system.  Global producers of JP-5, Jet A, and Jet A-1 aviation turbine fuels may benefit from this technology in their efforts to minimize the deleterious effects of copper introduced to these fuels during product handling and desulfurization processes.  This technology may also reduce maintenance cost for commercial aviation.

REFERENCES:

1. “Detail Specification Turbine Fuel, Aviation, Grades JP-4 and JP-5, MIL-DTL-5624V”, 11 July 2013. http://everyspec.com/MIL-SPECS/MIL-SPECS-MIL-DTL/MIL-DTL-5624V_47197/

2. Hazlett, Robert N. “Thermal Oxidation Stability of Aviation Turbine Fuels, Chapter VIII.” American Society for Testing and Materials, December 1991, ASTM D3241.
https://books.google.com/books?id=e-h5UZefdZcC&pg=PA114&lpg=PA114&dq=copper+jp-5&source=bl&ots=hj7P98bCE-&sig=yTI0WkUdTmOYntZjxJtK7a6hxzs&hl=en&sa=X&ved=0ahUKEwj-luvZ2erRAhUK84MKHUsWCesQ6AEIIzAB#v=onepage&q=copper%20jp-5&f=false

3. Puranik, Dhanajay B. et al. “Copper Removal from Fuel by Solid-Supported Palyamine Chelating Agents.” American Chemical Society Energy & Fuels 1998, 12, 792-797.
http://pubs.acs.org/doi/pdf/10.1021/ef980006y

4. Lu, Qin et al. “Rapid Determination of Dissolved Copper in Jet Fuels Using Bathocuproine.” American Chemical Society, Energy & Fuels 2003, 17, 699-704. http://pubs.acs.org/doi/pdf/10.1021/ef0202642

5. Hazlett, Robert N. and Morris, Robert E. “Thermal Oxidation Stability of Aviation Turbine Fuel, a Survey.” 4th International Conference on Stability and Handling of Liquid Fuels Orlando, Florida, USA, November 19-22, 1991. http://iash.conferencespot.org/56077-iash-1991-1.652968/t-001-1.653105/f-005-1.653249/a-022-1.653274/ap-022-1.653275?qr=1

KEYWORDS: Jet Propellant 5 (JP-5) Fuel; Aviation Turbine Fuels; Copper Nickel (CuNi) Piping; Thermal Oxidation Stability Standards; Soluble Metal Chelant Additives; Polyamine Chelating Agents