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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 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
NASA NTRS1991

Monitoring and control of atmosphere in a closed environment

Applications requiring new technologies for atmosphere monitoring and control in the closed environment and their principal functions aboard the Space Station Freedom are described. Oxygen loop closure, involving the conversion of carbon dioxide to oxygen; carbon dioxide reduction and removal; and monitoring of atmospheric contamination are discussed. The Trace Contaminant Monitor, the Major Constituent Analyzer, the Carbon Dioxide Monitor, and the Particulate Counter Monitor are discussed.

Humphries, R.↗
NASA NTRS2011

Plasma Pyrolysis Assembly Regeneration Evaluation

In April 2010 the Carbon Dioxide Reduction Assembly (CRA) was delivered to the International Space Station (ISS). This technology requires hydrogen to recover oxygen from carbon dioxide. This results in the production of water and methane. Water is electrolyzed to provide oxygen to the crew. Methane is vented to space resulting in a loss of valuable hydrogen and unreduced carbon dioxide. This is not critical for ISS because of the water resupply from Earth. However, in order to have enough oxygen for long-term missions, it will be necessary to recover the hydrogen to maximize oxygen recovery. Thus, the Plasma Pyrolysis Assembly (PPA) was designed to recover hydrogen from methane. During operation, the PPA produces small amounts of carbon that can ultimately reduce performance by forming on the walls and windows of the reactor chamber. The carbon must be removed, although mechanical methods are highly inefficient, thus chemical methods are of greater interest. The purpose of this effort was to determine the feasibility of chemically removing the carbon from the walls and windows of a PPA reactor using a pure carbon dioxide stream.

Medlen, Amber↗
NASA NTRS1991

Physical/chemical closed-loop water-recycling

Water needs, water sources, and means for recycling water are examined in terms appropriate to the water quality requirements of a small crew and spacecraft intended for long duration exploration missions. Inorganic, organic, and biological hazards are estimated for waste water sources. Sensitivities to these hazards for human uses are estimated. The water recycling processes considered are humidity condensation, carbon dioxide reduction, waste oxidation, distillation, reverse osmosis, pervaporation, electrodialysis, ion exchange, carbon sorption, and electrochemical oxidation. Limitations and applications of these processes are evaluated in terms of water quality objectives. Computerized simulation of some of these chemical processes is examined. Recommendations are made for development of new water recycling technology and improvement of existing technology for near term application to life support systems for humans in space. The technological developments are equally applicable to water needs on Earth, in regions where extensive water recycling is needed or where advanced water treatment is essential to meet EPA health standards.

Herrmann, Cal C.↗
NASA NTRS1990

Physical/chemical closed-loop water-recycling for long-duration missions

Water needs, water sources, and means for recycling water are examined in terms appropriate to the water quality requirements of a small crew and spacecraft intended for long duration exploration missions. Inorganic, organic, and biological hazards are estimated for waste water sources. Sensitivities to these hazards for human uses are estimated. The water recycling processes considered are humidity condensation, carbon dioxide reduction, waste oxidation, distillation, reverse osmosis, pervaporation, electrodialysis, ion exchange, carbon sorption, and electrochemical oxidation. Limitations and applications of these processes are evaluated in terms of water quality objectives. Computerized simulation of some of these chemical processes is examined. Recommendations are made for development of new water recycling technology and improvement of existing technology for near term application to life support systems for humans in space. The technological developments are equally applicable to water needs on earth, in regions where extensive water ecycling is needed or where advanced water treatment is essential to meet EPA health standards.

Herrmann, Cal C.↗
NASA NTRS2011

Influence of Oxygenated Compounds on Reaction Products in a Microwave Plasma Methane Pyrolysis Assembly for Post-Processing of Sabatier Methane

The state-of-the-art Carbon Dioxide Reduction Assembly (CRA) was delivered to the International Space Station (ISS) in April 2010. The system is designed to accept carbon dioxide from the Carbon Dioxide Removal Assembly and hydrogen from the Oxygen Generation Assembly. The two gases are reacted in the CRA in a Sabatier reactor to produce water and methane. Venting of methane results in an oxygen resupply requirement of about 378 lbs per crew member per year. If the oxygen is supplied as water, the total weight for resupply is about 476 lb per crew member per year. For long-term missions beyond low Earth orbit, during which resupply capabilities will be further limited, recovery of hydrogen from methane is highly desirable. For this purpose, NASA is pursuing development of a Plasma Pyrolysis Assembly (PPA) capable of recovering hydrogen from methane. Under certain conditions, water vapor and carbon dioxide (nominally intended to be separated from the CRA outlet stream) may be present in the PPA feed stream. Thus, testing was conducted in 2010 to determine the effect of these "oxygenated" compounds on PPA performance, particularly the effect of inlet carbon dioxide and water variations on the PPA product stream. This paper discusses the test set-up, analysis, and results of this testing

Mansell, J. Matthew↗
NASA NTRS2012

Influence of Oxygenated Compounds on Reaction Products in a Microwave Plasma Methane Pyrolysis Assembly for Post-Processing of Sabatier Methane

The state-of-the-art Carbon Dioxide Reduction Assembly (CRA) was delivered to the International Space Station (ISS) in April 2010. The system is designed to accept carbon dioxide from the Carbon Dioxide Removal Assembly and hydrogen from the Oxygen Generation Assembly. The two gases are reacted in the CRA in a Sabatier reactor to produce water and methane. Venting of methane results in an oxygen resupply requirement of about 378 lbs per crew member per year. If the oxygen is supplied as water, the total weight for resupply is about 476 lb per crew member per year. For long-term missions beyond low Earth orbit, during which resupply capabilities will be further limited, recovery of hydrogen from methane is highly desirable. For this purpose, NASA is pursuing development of a Plasma Pyrolysis Assembly (PPA) capable of recovering hydrogen from methane. Under certain conditions, water vapor and carbon dioxide (nominally intended to be separated from the CRA outlet stream) may be present in the PPA feed stream. Thus, testing was conducted in 2010 to determine the effect of these oxygenated compounds on PPA performance, particularly the effect of inlet carbon dioxide and water variations on the PPA product stream. This paper discusses the test set-up, analysis, and results of this testing.

Mansell, J. Matthew↗
NASA NTRS2020

Developmental Efforts of an Electrochemical Oxygen Recovery System for Advanced Life Support

The current State of Art (SOA) Environmental Control and Life Support System (ECLSS) oxygen recovery system onboard the International Space Station (ISS) is complex, heavy, and power consuming system that recovers approximately 50% of the oxygen (O2) from metabolic carbon dioxide (CO2). For future long-duration missions, O2 recovery systems will need to be highly reliable, efficient, and recover maximum metabolic CO2. A minimum of 75% O2 recovery is required for future O2 recovery systems. Investigations into various technologies to help meet these requirements for exploration are ongoing; however, most of these proposed technologies ultimately result in a more complex system. A Macrofluidic Electrochemical Reactor (MFECR) is one proposed technology development effort currently underway at NASA Marshall Space Flight Center (MSFC) that has the potential to significantly reduce the complexity of ECLSS O2 recovery system. The MFECR operates at standard conditions, giving it an advantage over other technologies being investigated, which require high temperatures resulting in heavy reactors and high power consumption. The MFECR would replace three pieces of hardware for future ECLSS architectures: the current Carbon Dioxide Reduction Assembly (Sabatier reactor), the Plasma Pyrolysis Assembly (PPA), and the Oxygen Generation Assembly (OGA). It is designed to interface directly with the Carbon Dioxide Removal Assembly (CDRA) and the Water Processor Assembly (WPA). This allows for a less complex system and higher reliability than the current SOA as well as reduced power, weight and H2O consumption of ECLSS. Here, we will discuss the current technology development efforts of the MFECR and how this technology may aide in the advancement of future long-duration life support systems.

Brown, Brittany R.↗
NASA NTRSDate not supplied

Developmental Efforts of an Electrochemical Oxygen Recovery System for Advanced Life Support

The current State of Art (SOA) Environmental Control and Life Support System (ECLSS) oxygen recovery system onboard the International Space Station (ISS) is a complex, heavy, and power consuming system that recovers approximately 50% of the oxygen (O2) from metabolic carbon dioxide (CO2). For future long-duration missions, O2recovery systems will need to be highly reliable, efficient, and recover maximum metabolic CO2. Investigations into various technologies to help meet these requirements for exploration are ongoing; however, most of these proposed technologies ultimately result in a more complex system. A Macrofluidic Electrochemical Reactor (MFECR) is one proposed technology development effort currently underway at NASA Marshall Space Flight Center (MSFC) that has the potential to significantly reduce the complexity of ECLSSO2recovery system. The MFECR operates at standard conditions, giving it an advantage over other technologies being investigated, which require high temperatures resulting in heavy reactors and high power consumption. The MFECR would replace three pieces of hardware for future ECLSS architectures: the current Carbon Dioxide Reduction Assembly (Sabatier reactor), the Plasma Pyrolysis Assembly (PPA), and the Oxygen Generation Assembly(OGA). It is designed to interface directly with the Carbon Dioxide Removal Assembly (CDRA) and the Water Processor Assembly (WPA). This allows for a less complex system and higher reliability than the current SOA as well as reduced power, weight and H2Oconsumption of ECLSS. Here, we will discuss the current development efforts of the MFECR and how this technology may aide in the advancement of future long-duration life support systems.

Brittany R Brown↗
NASA NTRS2015

Evaluation of an Atmosphere Revitalization Subsystem for Deep Space Exploration Missions

An Atmosphere Revitalization Subsystem (ARS) suitable for deployment aboard deep space exploration mission vehicles has been developed and functionally demonstrated. This modified ARS process design architecture was derived from the International Space Station's (ISS) basic ARS. Primary functions considered in the architecture include trace contaminant control, carbon dioxide removal, carbon dioxide reduction, and oxygen generation. Candidate environmental monitoring instruments were also evaluated. The process architecture rearranges unit operations and employs equipment operational changes to reduce mass, simplify, and improve the functional performance for trace contaminant control, carbon dioxide removal, and oxygen generation. Results from integrated functional demonstration are summarized and compared to the performance observed during previous testing conducted on an ISS-like subsystem architecture and a similarly evolved process architecture. Considerations for further subsystem architecture and process technology development are discussed.

Perry, Jay L.↗
NASA NTRS2016

Filtration of Carbon Particulate Emissions from a Plasma Pyrolysis Assembly

NASA is investigating plasma pyrolysis as a candidate technology that will enable the recovery of hydrogen from the methane produced by the ISS Sabatier Reactor. The Plasma Pyrolysis Assembly (PPA) is the current prototype of this technology which converts the methane product from the Carbon Dioxide Reduction Assembly (CRA) to acetylene and hydrogen with 90% or greater conversion efficiency. A small amount of solid carbon particulates are generated as a side product and must be filtered before the acetylene is removed and the hydrogen-rich gas stream is recycled back to the CRA. We discuss developmental work on several options for filtering out the carbon particulate emissions from the PPA exit gas stream. The filtration technologies and concepts investigated range from fibrous media to monolithic ceramic and sintered metal media. This paper describes the different developed filter prototypes and characterizes their performance from integrated testing at the Environmental Chamber (E-Chamber) at MSFC. In addition, characterization data on the generated carbon particulates, that help to define filter requirements, are also presented.

methane↗
NASA NTRSDate not supplied

Sustainable Resource Recovery from Trash, Waste, and Overboard Venting

Space travel and planetary missions for long-endurance human presence require Environmental Control and Life Support (ECLS) loop-closure. The air and water resource loops are generally closed with their processes having been established through extensive development, testing, and long-term use on International Space Station. Closure of the air and water loops have enabled oxygen and hydrogen sustainability. Carbon sustainability has yet to be addressed. Waste and trash, which also contains hydrogen and oxygen and abundant carbon have not been developed to the extent air and water have. Waste and trash have generally been dealt with in terms of simple safening, storage, and disposal. In externally disposing of waste, which includes C1 and C2 hydrocarbon gases, lost resources not only increase mission cost they can result in space and planetary pollution that can lead to unfavorable public opinion. With all this in mind, we explore the idea of carbon sustainability within closed-cycle waste, trash, and C1/C2 reprocessing. Starting from the current ECLS System roadmap, we identify resources that are not yet captured in closed-cycle processes but are lost when crossing the thermodynamic boundaries of an open system. Such pseudo-resources are trash, waste, and the gaseous carbon products of carbon dioxide reduction. We then consider different means and processes for minimizing pseudo-resource loss so as to “close the carbon loop.” There are cases in which pseudo-resources need to be externally discarded, such as reducing spacecraft acceleration mass. In this case we examine various processes that can be beneficial to missions even when these pseudo-resources are lost. An example would be the conversion of waste into propellant, which can produce thrust while at the same time reducing mass for transit acceleration (and ultimately propellant mass at launch), in which case we propose a means for evaluating the value of converting waste into propellant for different propulsion systems.

waste↗
NASA NTRSDate not supplied

Kinetic Model Development of the Carbon Vapor Deposition Reactor to Predict Performance Versus Design

To enable complete closure of a Sabatier-based atmosphere revitalization system where oxygen recovery is predicated by carbon dioxide reduction to methane and water, there must be a means of recovering the hydrogen from the byproduct methane. Honeywell’s carbon vapor deposition (CVD) reactor is a potential technology that provides a thermochemical means by which methane decomposes at high temperatures (> 1,000 °C) into hydrogen, solid carbon, and a small percentage of hydrocarbons. This advanced methane pyrolysis reactor utilizes a carbon fiber substrate to capture and immobilize the solid pyrolytic carbon rather than allowing continuation toward undesirable soot. The CVD reactor is a highly dynamic system whose characteristic geometry changes while operating. The reactor model was developed to provide predictive performance assessment capabilities at different operating conditions, geometries, and configurations to aid in technology development. Modeling of the CVD reactor considered the multitude of simultaneous and interdependent physicochemical processes that are entailed, including: (1) the homogeneous gas-phase pyrolysis reactions, (2) the heterogeneous deposition reactions, and (3) the transport of gaseous species in the reactor domains. A 1-D CVD reactor model was developed based on a general packed-bed, axial-dispersion plug flow reactor model with a solid substrate balance to account for carbon deposition. The model includes 59 species and 243 reactions constituting the methane pyrolysis reaction network, carbon deposition, and interconversions of oxygenate species. The reactor model was compared to brassboard test data, where it was shown to be able to capture the pertinent physicochemical phenomena as evidenced by its agreement with short-duration run data (i.e., looking at different temperature and flow rate conditions), as well as trend agreement with the brassboard reactor’s long-duration test data. Recommendations are provided on further model development steps as well as its use cases.

Air Revitalization↗
NASA NTRS2003

Sabatier Engineering Development Unit

To facilitate life support system loop closure on board the International Space Station (ISS), the Node 3 Oxygen Generation System (OGS) rack contains a functional scar to accommodate a carbon dioxide reduction assembly (CRA). As part of the effort to better understand and define the functional scar, significant risk mitigation activities have been performed. To address integration risks, a CRA Engineering Development Unit (EDU) has been developed that is functionally equivalent to a flight CRA and is suitable for integrating with ground based carbon dioxide removal and oxygen generation systems. The CRA EDU has been designed to be functionally equivalent to the Sabatier Reactor Subsystem (SRS) portion of the CRA. The design of the CRA EDU and testing results in a stand alone configuration with simulated OGA and CDRA interfaces are reported. Carbon dioxide flow control is a major area requiring development since the size of the CO2 accumulator may result in periods of CRA starvation. The capability of the CO2 flow control algorithm to effectively manage integrated CRA operations is discussed.

Perry, Jay↗
NASA NTRSDate not supplied

A Two-Stage Regenerable Filter for Collection and Disposal of Carbon Fines

NASA is investigating the use of the Plasma Pyrolysis Assembly (PPA), which is a methane post-processing technology with the goal to recover hydrogen from the Carbon dioxide Reduction Assembly (CRA) currently onboard the International Space Station (ISS). The PPA can theoretically recover 75% of hydrogen from methane produced by the CRA. During methane processing the PPA creates roughly 40 mg/hr of carbon dust when operating at 4 crew member levels. The unwanted fines need to be removed from the stream to prevent any clogging of downstream components. The Regenerable Carbon Filter (RCF) was designed by Umpqua Research Company to address the carbon particulate created in the PPA. The RCF includes two stages. The first is an electrostatic precipitator designed to collect ultrafine particles. The second is a low pressure drop physical filter. Both filters are made of heat tolerant materials to allow regeneration of the filtration capacity by O2 oxidation of captured carbon. This paper will discuss the RCF hardware and test plans.

Filtration, Environmental Control, Life Support↗
NASA NTRS2022

Clean Air Policies Are Key for Successfully Mitigating Arctic Warming

A tighter integration of modeling frameworks for climate and air quality is urgently needed to assess the impacts of clean air policies on future Arctic and global climate. We combined a new model emulator and comprehensive emissions scenarios for air pollutants and greenhouse gases to assess climate and human health co-benefits of emissions reductions. Fossil fuel use is projected to rapidly decline in an increasingly sustainable world, resulting in far-reaching air quality benefits. Despite human health benefits, reductions in sulfur emissions in a more sustainable world could enhance Arctic warming by 0.8 °C in 2050 relative to the 1995–2014, thereby offsetting climate benefits of greenhouse gas reductions. Targeted and technically feasible emissions reduction opportunities exist for achieving simultaneous climate and human health co-benefits. It would be particularly beneficial to unlock a newly identified mitigation potential for carbon particulate matter, yielding Arctic climate benefits equivalent to those from carbon dioxide reductions by 2050.

Atmospheric chemistry↗
NASA NTRS2013

Sabatier Catalyst Poisoning Investigation

The Carbon Dioxide Reduction Assembly (CRA) on the International Space Station (ISS) has been operational since 2010. The CRA uses a Sabatier reactor to produce water and methane by reaction of the metabolic CO2 scrubbed from the cabin air and the hydrogen byproduct from the water electrolysis system used for metabolic oxygen generation. Incorporating the CRA into the overall air revitalization system has facilitated life support system loop closure on the ISS reducing resupply logistics and thereby enhancing longer term missions. The CRA utilizes CO2 which has been adsorbed in a 5A molecular sieve within the Carbon Dioxide Removal Assembly, CDRA. There is a potential of compounds with molecular dimensions similar to, or less than CO2 to also be adsorbed. In this fashion trace contaminants may be concentrated within the CDRA and subsequently desorbed with the CO2 to the CRA. Currently, there is no provision to remove contaminants prior to entering the Sabatier catalyst bed. The risk associated with this is potential catalyst degradation due to trace organic contaminants in the CRA carbon dioxide feed acting as catalyst poisons. To better understand this risk, United Technologies Aerospace System (UTAS) has teamed with MSFC to investigate the impact of various trace contaminants on the CRA catalyst performance at relative ISS cabin air concentrations and at about 200/400 times of ISS concentrations, representative of the potential concentrating effect of the CDRA molecular sieve. This paper summarizes our initial assessment results.

Nallette, Tim↗
NASA NTRS1989

Analysis of an algae-based CELSS. Part 2: options and weight analysis

Life support components are evaluated for application to an idealized closed life support system which includes an algal reactor for food production. Weight-based trade studies are reported as "break-even" time for replacing food stores with a regenerative bioreactor. It is concluded that closure of the life support gases (oxygen recovery) depends on the carbon dioxide reduction chemistry and that an algae-based food production can provide an attractive alternative to re-supply for longer duration missions.

Bioreactors↗