Production of Lunar Oxygen by Vacuum Pyrolysis · 2005-11-10 · Production of Lunar Oxygen by...
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Production of Lunar Oxygen by Vacuum Pyrolysis Dr. Eric Cardiff, Brian Pomeroy NASA GSFC Lt. John Matchett USAF / GWU October 25th, 2005 L Lunar OX OXygen Project
Transcript of Production of Lunar Oxygen by Vacuum Pyrolysis · 2005-11-10 · Production of Lunar Oxygen by...
Production of Lunar Oxygen by Vacuum Pyrolysis
Dr. Eric Cardiff, Brian PomeroyNASA GSFC
Lt. John MatchettUSAF / GWU
October 25th, 2005
LLunar OXOXygen Project
Goals• Demonstrate the production of oxygen from a
lunar simulant by the vacuum pyrolysis technique, including all the subcomponents.– Model the system to indicate potential yields.
• Demonstrate the feasibility of a large solar concentration system (two approaches).
• Examine the potential for the system to be used to extract other volatiles from the lunar regolith.
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Vacuum Pyrolysis Overview
• Vacuum pyrolysis is based on the vaporization reaction of metal oxides that simultaneously reduces the oxide and produces O2 at temperatures between 2000ºC and 2600ºC.
• The reduced oxide can be condensed out of the low-pressure gas at temperatures below ~500ºC
Production of Lunar Oxygen by Vacuum Pyrolysis
)g(221
)g()s(2 OSiOSiO +→
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• Has a much higher potential efficiency (6.3% - 21%).• Requires no imported chemicals.• Can potentially produce metallic byproducts from the
condensation.• First proposed by Steurer and Nerad in 1983.• The most significant experimental work, Senior, 1991, was
a proof-of-principle experiment that showed pressure increase due to gas production (order of µg) from heated minerals. O2 was not recovered or sampled.
• Sauerborn, DLR, has done some proof of principle work with a high flux solar furnace at relatively low temperature (1700K).
Production of Lunar Oxygen by Vacuum Pyrolysis
Vacuum Pyrolysis
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Vacuum Pyrolysis FlowchartProduction of Lunar Oxygen by Vacuum Pyrolysis
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Mining
Reactor Condensation Slag Discharge
O2 Storage
Solar EnergySolar EnergyMinimal
Benefication
Benefication:• Pit Scalping (remove large rocks)• Crushing
Structural Materials
Non-vaporized Slag Discharge
Condensate Removal
Gas Sensor Instrumentation
Experimental Approach
Production of Lunar Oxygen by Vacuum Pyrolysis
Two different solar concentrator designs
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Fresnel System
O2Storage
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Fresnel Concentrator
WindowScroll PumpCrucible
Radiation Shield
Thermal Condensation
System
Coolant Circulator
Ceramic Support
Fresnel System
Production of Lunar Oxygen by Vacuum Pyrolysis
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Prototype System in Testing
Production of Lunar Oxygen by Vacuum Pyrolysis
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Concentrator System
O2Storage
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Mirror Concentrator
Scroll Pump
Thermal Condensation
System
Coolant Circulator
Crucible
Window
Mass Spectrometer
3.8m Diameter Reflector System
Production of Lunar Oxygen by Vacuum Pyrolysis
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Experiment StatusThe Fresnel system is complete and operational
– We have demonstrated run times of over an hour.– Limiting factor is the vacuum window. We are currently
investigating the failure mechanisms of the window.– Condensation occurs within inches of the surface – the
condensation system is integrated into the vaporization chamber.
– All of the instrumentation is operational.The reflector system is built.
– Three techniques were evaluated for mirroring.– The combustion chamber for this has been designed and
built.
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Instrumentation
• Residual Gas Analyzer: gas analysis.• Pyrometer: surface temperature (>1600 C).• Thermocouple: surface temperature in-situ• IR thermometer: chamber and window temps.• Scanning Electron Microscope with X-ray
analysis: chemical and morphological characterization of the pyrolyzed and condensed surfaces.
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Current Results
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Production of Lunar Oxygen by Vacuum Pyrolysis
Current Experimental Results
• Mass loss was measured from ilmentite vaporization.– Images, SEMs, and temperature data.– Mass loss was measured to be several orders of
magnitude more than out-gassing of volatiles (tested in vacuum and oven): several grams.
• A mass loss has also been measured from enstatite– It is also significantly more than outgassing.– Condensation of enstatite was also studied. It is all
within 1.6 inches (4 cm) of the sample.• A substantial mass loss was also obtained with
MLS-1A.October 25th, 2005
Production of Lunar Oxygen by Vacuum Pyrolysis
Current Experimental Results• The SEM was used to probe the chemistry of the
slag.• Ilmenite slag shows a relative increase in the
amount of titanium present at the vaporized surface, and a relative decrease in the amount of oxygen present at the surface. This indicates the oxygen is in fact leaving the system.
• The condensate also appears to be reduced by SEM analysis.
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Production of Lunar Oxygen by Vacuum Pyrolysis
Current Experimental Results
Particles of Ti remain at the surface while the iron has melted and vaporized.
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Production of Lunar Oxygen by Vacuum Pyrolysis
Ilmenite Test Picture
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Production of Lunar Oxygen by Vacuum Pyrolysis
MLS-1A Test Picture
MLS-1A is a lunar simulant. October 25th, 2005
Production of Lunar Oxygen by Vacuum Pyrolysis
Condensate from Ilmenite Test
Picture taken from the chamber wall above the surface of the non-vaporized slag.The material on the walls is reduced oxide material that condensed from the vapors, and splatter from boiling .
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Production of Lunar Oxygen by Vacuum Pyrolysis
Current Modeling Results
Yield should be ~10% for ilmenite!
If we heat the equilibrium to 2500 C and then condense out the remaining oxidized gasses, only the oxygen system is left.
October 25th, 2005The vaporization will shift left for lower pressure.
Future Work
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Pumping ModificationsRGA measurements have not been successful because a leak valve had to be used to reduce the chamber pressure.The setup was modified to lower the chamber pressure and integrate the RGA directly into the flow.
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Flex Hose
RGA
Turbopump
Leak Valve
ScrollPump
Old Design
Flex Hose
RGA
Turbopump
ScrollPump
New Design
Although it is not possible to examine with regolith simulantshere on Earth, the same system can be preheated to ~700K to extract many of the volatiles that are present in the lunar regolith. This includes the H2 and He3 that is embedded in the lunar regolith by the solar wind, as well as indigenous, or meteoritic, volatile species of scientific interest (Ar, etc.).
Analysis has been performed to predict potential yields of these volatile species in the lunar regolith.
The in-situ production of volatile materials on the moon will be difficult, but the vacuum pyrolysis technique CAN be used to support scientific studies.
Production of Lunar Oxygen by Vacuum Pyrolysis
Volatile Species
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Production of Lunar Oxygen by Vacuum Pyrolysis
Implementation Plan
The second flight, the demonstration mission, requires further development of those components which were not direct heritage from the instrument flight. The demonstration mission is fully capable of producing oxygen from lunar regolith.
The instrument/volatiles mission will demonstrate some of the key technologies, such as the window and collector. This mission advances the technology to TRL 5.
The pilot plant can be modular in design and scaled to meet the desired production rate.The pilot plant serves as a prototype for a future production plant.
