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Results for “OXYGEN PRODUCTION”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
NASA NTRS1992

Reduction of iron-bearing lunar minerals for the production of oxygen

The kinetics and mechanism of the reduction of simulants of the iron-bearing lunar minerals olivine ((Fe,Mg)2SiO4), pyroxene ((Fe,Mg,Ca)SiO3), and ilmenite (FeTiO3) are investigated, extending previous work with ilmenite. Fayalite is reduced by H2 at 1070 K to 1480 K. A layer of mixed silica glass and iron forms around an unreacted core. Reaction kinetics are influenced by permeation of hydrogen through this layer and a reaction step involving dissociated hydrogen. Reaction mechanisms are independent of Mg content. Augite, hypersthene, and hedenbergite are reduced in H2 at the same temperatures. The products are iron metal and lower iron silicates mixed throughout the mineral. Activation energy rises with calcium content. Ilmenite and fayalite are reduced with carbon deposited on partially reduced minerals via the CO disproportionation reaction. Reduction with carbon is rapid, showing the carbothermal reduction of lunar minerals is possible.

Massieon, Charles↗
NASA NTRS1981

Basic investigation into the production of oxygen in a solid electrolyte process

Mission analyses indicated that by extracting oxygen from the Martian atmosphere, which consists primarily of carbon dioxide, the launch mass of a spacecraft can be reduced by such an amount that samples from the planet can be returned to earth. The solid electrolyte process for producing O2 from CO2 was investigated. A model of the thermodynamic and electrochemical processes in the electrolyte cell was postulated, thereby establishing the parameters influencing the effectiveness and efficiency of an in situ O2 production system. The major operating parameters were investigated over a wide range of temperature and pressure. Operating limits imposed by the solid electrolyte material, 8% yttria stabilized zirconia, were determined as a function of the operating temperature.

Richter, R.↗
NASA NTRS1985

Lunar bases and space activities of the 21st century

The present conference gives attention to such major aspects of lunar colonization as lunar base concepts, lunar transportation, lunar science research activities, moon-based astronomical researches, lunar architectural construction, lunar materials and processes, lunar oxygen production, life support and health maintenance in lunar bases, societal aspects of lunar colonization, and the prospects for Mars colonization. Specific discussions are presented concerning the role of nuclear energy in lunar development, achromatic trajectories and the industrial scale transport of lunar resources, advanced geologic exploration from a lunar base, geophysical investigations of the moon, moon-based astronomical interferometry, the irradiation of the moon by particles, cement-based composites for lunar base construction, electrostatic concentration of lunar soil minerals, microwave processing of lunar materials, a parametric analysis of lunar oxygen production, hydrogen from lunar regolith fines, metabolic support for a lunar base, past and future Soviet lunar exploration, and the use of the moons of Mars as sources of water for lunar bases.

Mendell, W. W.↗
NASA NTRS1998

Low-Power CO2 Compression Technology

Presently, the most feasible processes for extracting oxygen from the Martian atmosphere either require or are much more efficient if the atmospheric CO2 feed is provided at pressures well above the Martian ambient. Electrical power for performing the desired compression is likely to be an extremely limited resource on the Mars surface. Even if "cheap" nuclear power is available at a central site/launch facility where rocket propellent and oxidant are manufactured, life support applications needing oxygen production capabilities, such as rovers, portable life support, and remote or independent exploration stations, will benefit from extremely low-power atmospheric compression technology, such as the one discussed here. Our experiments show the potential of one very low-power approach to performing CO2 compression that uses the Mars diurnal temperature cycle to drive a heat engine. The 1 kg compressor has been tested over an extended period in a Mars environmental simulation chamber that mimics the composition, pressure, and temperature cycles that can occur on the Martian surface. The simple design, which has very few moving parts and can easily be scaled to larger or smaller sizes, produces a CO2 stream at a rate of 100 g/ day at a quality and pressure suitable for a variety of oxygen production processes.

Finn, John E.↗
NASA NTRS2010

Three Years of on Orbit ISS Oxygen Generation System Operation 2007-2010

The International Space Station (ISS) United States Orbital Segment (USOS) Oxygen Generation System (OGS) has accumulated 240 days of continuous operation at varied oxygen production rates within the US Laboratory Module (LAB) since it was first activated in July 2007. OGS relocated from the ISS LAB to Node 3 during 20A Flight (February 2010). The OGS rack delivery was accelerated for on-orbit checkout in the LAB, and it was launched to ISS in July of 2006. During the on-orbit checkout interval within the LAB from July 2007 to October 2008, OGS operational times were limited by the quantity of feedwater in a Payload Water Reservoir (PWR) bag. Longer runtimes are now achievable due to the continuous feedwater availability after ULF2 delivery and activation of the USOS Water Recovery System (WRS) racks. OGS is considered a critical function to maintaining six crew capability. There have been a number of failures which interrupted or threatened to interrupt oxygen production. Filters in the recirculation loop have clogged and have been replaced, Hydrogen sensors have fallen out of specifications, a pump delta pressure sensor failed, a pump failed to start, and the voltage on the cell stack increased out of tolerance. This paper will discuss the operating experience and characteristics of the OGS, as well as operational issues and their resolution.

Diderich, Greg S.↗
NASA NTRS2008

Analysis of Thermal and Reaction Times for Hydrogen Reduction of Lunar Regolith

System analysis of oxygen production by hydrogen reduction of lunar regolith has shown the importance of the relative time scales for regolith heating and chemical reaction to overall performance. These values determine the sizing and power requirements of the system and also impact the number and operational phasing of reaction chambers. In this paper, a Nusselt number correlation analysis is performed to determine the heat transfer rates and regolith heat up times in a fluidized bed reactor heated by a central heating element (e.g., a resistively heated rod, or a solar concentrator heat pipe). A coupled chemical and transport model has also been developed for the chemical reduction of regolith by a continuous flow of hydrogen. The regolith conversion occurs on the surfaces of and within the regolith particles. Several important quantities are identified as a result of the above analyses. Reactor scale parameters include the void fraction (i.e., the fraction of the reactor volume not occupied by the regolith particles) and the residence time of hydrogen in the reactor. Particle scale quantities include the particle Reynolds number, the Archimedes number, and the time needed for hydrogen to diffuse into the pores of the regolith particles. The analysis is used to determine the heat up and reaction times and its application to NASA s oxygen production system modeling tool is noted.

Hegde, U.↗
NASA NTRS2009

Analysis of Thermal and Reaction Times for Hydrogen Reduction of Lunar Regolith

System analysis of oxygen production by hydrogen reduction of lunar regolith has shown the importance of the relative time scales for regolith heating and chemical reaction to overall performance. These values determine the sizing and power requirements of the system and also impact the number and operational phasing of reaction chambers. In this paper, a Nusselt number correlation analysis is performed to determine the heat transfer rates and regolith heat up times in a fluidized bed reactor heated by a central heating element (e.g., a resistively heated rod, or a solar concentrator heat pipe). A coupled chemical and transport model has also been developed for the chemical reduction of regolith by a continuous flow of hydrogen. The regolith conversion occurs on the surfaces of and within the regolith particles. Several important quantities are identified as a result of the above analyses. Reactor scale parameters include the void fraction (i.e., the fraction of the reactor volume not occupied by the regolith particles) and the residence time of hydrogen in the reactor. Particle scale quantities include the particle Reynolds number, the Archimedes number, and the time needed for hydrogen to diffuse into the pores of the regolith particles. The analysis is used to determine the heat up and reaction times and its application to NASA s oxygen production system modeling tool is noted.

Hegde, U.↗
NASA NTRS1991

Electrolytic production of oxygen from lunar resources

Oxygen is a valuable commodity in space. Substantial savings have been projected for future missions if oxygen could be produced on the moon from local resources. Some of the most promising approaches to extract oxygen from lunar resources involve electrochemical oxygen generation. In a straight-forward concept called "magma electrolysis", suitable oxides (silicates) are molten at 1300-1500 °C and the melt electrolyzed. Residual melt can be discarded after partial electrolysis. Alternatively, lunar soil may be dissolved in a molten salt and electrolyzed. In this approach, temperatures are lower and melt conductances higher, but electrolyte constituents need to be preserved. Both possibilities are being studied in the laboratory. In a different approach, ilmenite is reduced by hydrogen and the resulting water electrolyzed (Carbotek Process TM). Although know-how from terrestrial technology can be applied, the process task is unconventional and requires many innovative solutions. Time and effort needed for successful development should not be underestimated.

Rudolf Keller↗
NASA NTRS1989

Production of oxygen from lunar soil by molten salt electrolysis

A simple approach to utilizing lunar resources proposes to dissolve lunar soil, without or with little beneficiation, in a suitable molten salt and to electrolyze the oxides to oxygen and a metal byproduct. The envisioned process and the required technological advances are discussed. Promising electrolysis conditions have been identified in a recent experimental program to manufacture silicon and aluminum from anorthite.

Keller, Rudolf↗
NASA NTRS1991

Solar heating of common lunar minerals for the production of oxygen

The purpose of this work was to demonstrate the feasibility of vapor-phase reduction (pyrolysis) of lunar materials to produce oxygen. Solar furnace experiments were conducted on two common lunar minerals, ilmenite and anorthite. Thermodynamic equilibrium calculations predicted that ilmenite should show a larger pressure increase than anorthite under conditions of the experiments and this was confirmed by the experiments. The measured mass loss of the ilmenite sample was consistent with loss of oxygen by reduction of iron in the liquid phase; this result was also predicted from equilibrium calculations. Based on preliminary experiments and equilibrium calculations, the temperatures needed for pyrolysis are expected to be in the range of 2000 to 2500 K, giving total gas pressures of 0.01 to 1 torr. Bulk regolith can be used as a feedstock without extensive beneficiation. Further, selective condensation of metal-containing species from the gas phase may yield metallic iron and silicon as byproducts from the process.

Senior, C. L.↗
NASA NTRS1991

Lunar production of oxygen by electrolysis

Two approaches to prepare oxygen from lunar resources by direct electrolysis are discussed. Silicates can be melted or dissolved in a fused salt and electrolyzed with oxygen evolved at the anode. Direct melting and electrolysis is potentially a very simple process, but high temperatures of 1400-1500 C are required, which aggravates materials problems. Operating temperatures can be lowered to about 1000 C by employing a molten salt flux. In this case, however, losses of electrolyte components must be avoided. Experimentation on both approaches is progressing.

Keller, Rudolf↗
NASA NTRS1997

Investigation of the Reverse Water Gas Shift Reaction for Production of Oxygen From Mars Atmospheric Carbon Dioxide

The first phase of the research includes a comprehensive analytical study examining the potential applications for engineering subsystems and mission strategies made possible by such RWGS based subsystems, and will include an actual experimental demonstration and performance characterization of a full-scale brassboard RWGS working unit. By the time of this presentation the laboratory demonstration unit will not yet be operational but we will present the results of our analytical studies to date and plans for the ongoing work.

Meyer, Tom↗
NASA NTRS1992

Full system engineering design and operation of an oxygen plant

The production of oxygen from the indigenous resources on Mars is described. After discussing briefly the project's background and the experimental system design, specific experimental results of the electrolytic cell are presented. At the heart of the oxygen production system is a tubular solid zirconia electrolyte cell that will electrochemically separate oxygen from a high-temperature stream of Coleman grade carbon dioxide. Experimental results are discussed and certain system efficiencies are defined. The parameters varied include (1) the cell operating temperature; (2) the carbon dioxide flow rate; and (3) the voltage applied across the cell. The results confirm our theoretical expectations.

Colvin, James↗
NASA NTRS1994

Electrochemical Technology for Oxygen Removal and Measurement in the CELSS Test Facility, Engineering Development Unit

The Life Support Flight Program is evaluating regenerative technologies, including those that utilize higher plants, as a means to reduce resupply over long duration space missions. Constructed to assist in the evaluation process is the CELSS Test Facility Engineering Development Unit (CTF-EDU) an environmentally closed (less than 1% mass and thermal leakage) technology test bed. This ground based fully functional prototype is currently configured to support crop growth, utilizing the power, volume and mass resources allocated for two space station racks. Sub-system technologies were selected considering their impact on available resources, their ability to minimize integration issues, and their degree of modularity. Gas specific mass handling is a key sub-system technology for both biological and physical/chemical life support technologies. The CTF-EDU requires such a system to accommodate non-linear oxygen production from crops, by enabling the control system to change and sustain partial pressure set points in the growth volume. Electrochemical cells are one of the technologies that were examined for oxygen handling in the CTF-EDU. They have been additionally considered to meet other regenerative life support functions, such as oxygen generation, the production of potable water from composite waste streams, and for having the potential to integrate life support functions with those of propulsion and energy storage. An oxygen removal system based on an electrochemical cell was chosen for the EDU due to it's low power, volume and mass requirements (10W, 0.000027 cu m, 4.5 kg) and because of the minimal number of integration considerations. Unlike it's competitors, the system doesn't require post treatments of its byproducts, or heat and power intensive regenerations, that also mandate system redundancy or cycling. The EDUs oxygen removal system only requires two resources, which are already essential to controlled plant growth: electricity and water. Additionally, the amount of oxygen that is removed from the EDU is directly proportional to the cell input current via Faraday's constant, potentially allowing for a mol/electron measurement of photosynthetic rate. The currently operative oxygen removal system has maintained reduced oxygen set points within the EDU, and preparation is underway to verify of the accuracy of electrochemical measurement of oxygen production and hence, photosynthesis. This paper examines the working principles of the electrochemical cell, outlines the overall design of the oxygen removal system and its integration with other EDU subsystems, and summarizes test results obtained over crop growth cycles in the CTF-EDU.

Drews, Michael E.↗