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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 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

The mechanism of carboxylative cyclization of propargylamine by N-heterocyclic carbene complexes of Au(I)

Here, the complex [Au(IPr)(2-oxazolidinone)] (1 = IKa) was prepared from reaction of [Au(IPr)Cl] (2), K 2 CO 3 , and propargyl amine (PPA). Kinetic studies have been performed for acid cleavage of 1 to yield the oxazolidinone product and an [Au(IPr)(X)] adduct. The fastest rates of cleavage were found to occur for the hydrogen chloride salt of PPA (PPA-HCl) and for the CO 2 adduct of PPA, PPA-CO 2 = the carbamic acid (CA). This transformation was studied as a function of [CA], pressure of CO 2 as well as temperature. Detailed computational studies support the formation of a key intermediate and are also in agreement with a rapid carbonylation/decarbonylation reaction. The computed reactions mechanisms for addition of PPA-HCl and CA are also presented as well as the crystal structure of 1.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS1994

Template properties of oligocytidylates formed in the montmorillonite catalyzed condensation of ImpC

In an attempt to investigate the prebiotic formation of phosphodiester bond in RNA, we have studied the self condensation of 5'-phosphorimidazolide of adenosine (ImpA), in aqueous solutions containing 0.2 M sodium chloride and 0.075 M magnesium chloride at pH 8 using clay minerals as catalyst. In the presence of certain montmorillonites, oligomers containing up to ten monomer units in their chain were formed, while in control experiments, where no catalyst was added, the major product was 5',5'-diadenosine diphosphate, A(sup 5')ppA. In reactions carried out with ImpA: A(sup 5')ppA mixtures at 9:1 mole ratio, oligomers of the type A(sup 5')p(pA)(sub n) and (A(sup 5')p)(sub n)A(sup 5')ppA(pA)(sub n) formed at the expense of (pA)(sub n) type oligomers. Addition of A(sup 5')ppA to the reaction mixture increased the regiospecifity of 3',5'-link formation from 67% to 79%. The condensation of the 5'-phosphorimidazolide of cytidine, ImpC, was also carried out in the presence and absence of A(sup 5')ppA under the same conditions and oligomers containing up to twelve monomer units were obtained.

Ferris, James P.↗
DOE OSTI2020

A Dose Assessment Model for Radioactive Waste Exposed by Gully Erosion at West Valley - 20513

The Western New York Nuclear Service Center (WNYNSC), located approximately 48 km south of Buffalo, New York, is the site of a former nuclear fuel reprocessing and radioactive waste disposal facility. Spent nuclear fuel was processed there from 1966 to 1972, leaving behind radioactive and chemical wastes in two disposal areas and a waste tank farm. Site operations also resulted in releases of radioactivity to site soils, groundwater, and to surface waters draining the site. The New York State Energy Research and Development Authority (NYSERDA) and the U.S. Department of Energy (DOE) are collaborating in a process of decision making for decommissioning those facilities remaining at the WNYNSC following the completion of Phase 1 decommissioning. Neptune and Company, Inc. (Neptune) was contracted to develop a probabilistic performance assessment (PPA) computer model to assist the agencies in this process. The PPA Model includes a contaminant transport component focusing on the movement of contaminants within and among environmental media including groundwater and surface water transport, contaminant translocation by plants and animals, diffusion, and erosion. The model also includes evaluation of potential exposure and health effects for a Resident Farmer exposure scenario, where the Resident Farmer represents a critical group, described as that group of individuals reasonably expected to receive the greatest exposure to residual radioactivity for any applicable set of circumstances. The West Valley Site is located in the glaciated Allegheny Plateau region of western New York State. The waste reprocessing and disposal areas were constructed on a relatively fat area of plateau dissected by drainages of Buttermilk Creek, including Erdman Brook, Franks Creek, and Quarry Creek. An important aspect of the contaminant transport component of the PPA model is consideration of erosive processes such as slumping of the stream slopes and the advance of gullies from these streams. These erosion processes remove material from the plateau, growing the size of the creek valleys and making them wider and deeper. Of particular interest for the impact of erosion is radioactive waste contained in the Nuclear Regulatory Commission (NRC)-Licensed Disposal Area (NDA), the New York State-Licensed Disposal Area (SDA), and residual radiological inventory in the underground storage tanks at the Waste Tank Farm (WTF). The PPA Model is organized around geographically-defined facilities which were constructed upon the plateau, including the NDA, SDA, and WTF. Ongoing stream erosion processes will potentially transfer radioactive waste and residual inventory from these facilities to the ground surface on adjacent hillslope areas where erosion has breached the facility. Hence, it is important to evaluate the consequences of potential exposures to a Resident Farmer on the hillslopes below a breached facility. Two interrelated aspects of the dose assessment model related to hillslope exposure are discussed: 1) representation of the physical processes related to transport of radionuclides from facilities onto the hillslopes, and from the hillslopes into adjoining creeks where contaminated material migrates downstream with surface water and sediment, and; 2) adaptation of the activities associated with the Resident Farmer scenario to assess potential exposures to contamination in the hillslope areas. This discussion will cover the conceptual basis of the hillslope exposure and transport models, and also implementation in the PPA computer model. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2020

Utility-Scale Solar Data Update (2020 Edition) [Slides]

Berkeley Lab’s 2020 update of utility-scale solar data and trends provides an overview of key trends in the U.S. market, with a focus on 2019. Highlights of this year’s update include: More than 4.5 GWAC of utility-scale solar (i.e., ground-mounted solar projects larger than 5 MWAC) achieved commercial operations in 2019, bringing cumulative capacity to 29 GWAC. Projects are spread across all 10 regions that we track, though more heavily concentrated in the sunniest regions. The median installed cost of projects that came online in 2019 fell to $\$$1.4/WAC ($\$$1.2/WDC), down 20% from 2018 and down by more than 70% from 2010. 77% of projects and 88% of capacity added in 2019 used single-axis tracking. Average capacity factors range from 17% in the least-sunny regions to 30% where it is sunniest. Single-axis tracking adds roughly five percentage points to capacity factor in the regions with the strongest solar resource. Nationwide average levelized power purchase agreement (PPA) prices fell to $\$$24/MWh in 2019, down 17% from 2018 and more than 80% since 2010. Thirty-nine projects (totaling 4.2 GWAC) in our PPA price sample include battery storage (totaling 2.3 GWAC and 9.5 GWh). In the “lower 48” states, a number of these recent PV+battery PPAs have been inked in the mid-$\$$20/MWh range (levelized in 2019 dollars).Not including the 30% investment tax credit (ITC), the median levelized cost of energy (LCOE) from utility-scale PV has declined by 85% since 2010, to $\$$40/MWh in 2019. When the 30% ITC is included within the LCOE calculation, the median LCOE closely tracks the median PPA price over time. In higher-penetration markets like CAISO, the value of solar has been declining, but falling PPA prices have largely kept pace, preserving solar's net value. At the end of 2019, there were nearly 370 GW of solar in interconnection queues from all 7 ISOs and 30 additional utilities across the country. Nearly a third of this proposed solar capacity is paired with battery storage.

14 SOLAR ENERGY↗
NASA NTRS1993

Montmorillonite catalysis of RNA oligomer formation in aqueous solution. A model for the prebiotic formation of RNA

Oligomers of adenylic acid of up to the 11-mer in length are formed by the reaction of the phosphorimidazolide of adenosine (ImpA) in pH 8 aqueous solution at room temperature in the presence of Na(+)-montmorillonite. These oligomers are joined by phosphodiester bonds in which the 3',5'-linkage predominates over the 2',5'-linkage by a 2:1 ratio. Reaction of a 9:1 mixture of ImpA, A5'ppA results in the formation of oligomers with a 3:1 ratio of 3',5'- to 2',5'-linked phosphodiester bonds. A high proportion of these oligomers contain the A5'ppA grouping. A5'ppA reacts much more rapidly with ImpA than does 5'-ADP (ppA) or 5'-ATP (pppA). The exchangeable cation associated with the montmorillonite effects the observed catalysis with Li+, Na+, NH4+, and Ca2+ being the more effective while Mg2+ and Al3+ are almost ineffective catalysts. 2',5'-Linked oligomers, up to the tetramer in length, are formed using UO2(2+)-montmorillonite. The structure analysis of individual oligomer fractions was performed by selective enzymatic and KOH hydrolytic studies followed by HPLC analysis of the reaction products. It is concluded from the composition of the oligomers that the rate of addition ImpA to a 3'-terminus containing a 2',5'-linkage is slower than the addition to a nucleoside joined by a 3',5'-linked phosphodiester bond. The potential importance of mineral catalysis of the formation of RNA and other oligomers on primitive Earth is discussed.

Non-NASA Center↗
NASA NTRS2010

Sabatier Reactor System Integration with Microwave Plasma Methane Pyrolysis Post-Processor for Closed-Loop Hydrogen Recovery

The Carbon Dioxide Reduction Assembly (CRA) designed and developed for the International Space Station (ISS) represents the state-of-the-art in carbon dioxide reduction (CDRe) technology. The CRA produces water and methane by reducing carbon dioxide with hydrogen via the Sabatier reaction. The water is recycled to the Oxygen Generation Assembly (OGA) and the methane is vented overboard resulting in a net loss of hydrogen. The proximity to earth and the relative ease of logistics resupply from earth allow for a semi-closed system on ISS. However, long-term manned space flight beyond low earth orbit (LEO) dictates a more thoroughly closed-loop system involving significantly higher recovery of hydrogen, and subsequent recovery of oxygen, to minimize costs associated with logistics resupply beyond LEO. The open-loop ISS system for CDRe can be made closed-loop for follow-on missions by further processing methane to recover hydrogen. For this purpose, a process technology has been developed that employs a microwave-generated plasma to reduce methane to hydrogen and acetylene resulting in 75% theoretical recovery of hydrogen. In 2009, a 1-man equivalent Plasma Pyrolysis Assembly (PPA) was delivered to the National Aeronautics and Space Administration (NASA) for technical evaluation. The PPA has been integrated with a Sabatier Development Unit (SDU). The integrated process configuration incorporates a sorbent bed to eliminate residual carbon dioxide and water vapor in the Sabatier methane product stream before it enters the PPA. This paper provides detailed information on the stand-alone and integrated performance of both the PPA and SDU. Additionally, the integrated test stand design and anticipated future work are discussed.

Abney, Morgan B.↗
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 NTRS2016

Development of a Microwave Regenerative Sorbent-Based Hydrogen Purifier

This paper describes the design and fabrication of a Microwave Regenerative Sorbent-based Hydrogen Purifier (MRSHP). This unique microwave powered technology was developed for the purification of a hydrogen stream produced by the Plasma Pyrolysis Assembly (PPA). The PPA is a hydrogen recovery (from methane) post processor for NASA's Sabatier-based carbon dioxide reduction process. Embodied in the Carbon dioxide Reduction Assembly (CRA), currently aboard the International Space Station (ISS), the Sabatier reaction employs hydrogen to catalytically recover oxygen, in the form of water, from respiratory carbon dioxide produced by the crew. This same approach is base-lined for future service in the Air Revitalization system on extended missions into deep space where resupply is not practical. Accordingly, manned exploration to Mars may only become feasible with further closure of the air loop as afforded by the greater hydrogen recovery permitted by the PPA with subsequent hydrogen purification. By utilizing the well-known high sorbate loading capacity of molecular sieve 13x, coupled with microwave dielectric heating phenomenon, MRSHP technology is employed as a regenerative filter for a contaminated hydrogen gas stream. By design, freshly regenerated molecular sieve 13x contained in the MRSHP will remove contaminants from the effluent of a 1-CM scale PPA for several hours prior to breakthrough. By reversing flow and pulling a relative vacuum the MRSHP prototype then uses 2.45 GHz microwave power, applied through a novel coaxial antenna array, to rapidly heat the sorbent bed and drive off the contaminants in a short duration vacuum/thermal contaminant desorption step. Finally, following rapid cooling via room temperature cold plates, the MRSHP is again ready to serve as a hydrogen filter.

Wheeler, Richard R., Jr.↗
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 NTRS2024

3D Printed Materials Characterization for Rapid Prototyping and Plant Growth

Through KSC IRTD funding in 2022, this project brought a list of 18, 3D printed filaments into formal characterization testing to provide a reference for their behaviors under relevant applications. The project format set up a series of tests to expose 3D printed specimens. A total of 1,989 individual 3D printed test specimens were sent across KSC to be scrutinized by three laboratories to fulfill a multidisciplinary assessment of each material TRL. Testing started with 18 materials. Initially, seed germination assays in the PPA, sample materials were enclosed in petri dishes with lettuce seeds on damp germination paper. No significant impacts on lettuce seed germination were observed in this testing. Next, sample coupons were printed and sent for materials testing to the KSC Analysis/Mechanical and Environmental Testing Laboratory, where they were subjected to 14- and 30-day soak periods in solutions used to provide nutrients to plants or to sanitize hardware before and after use. Following a long soak typical of a 30-day plant growout in Hoagland’s solution, 14 materials gained more than 10% of their own mass. This indicated an increased potential for leaching or providing conditions that are not food safe. Materials that exceeded 15% absorption by mass were eliminated from further testing. Based off this result, the team continued with a core list of nine filaments to fulfill Tensile, Flexural, Biofilm formation, and plant growth testing. Those materials were PLA (Raise3D), ABS (Raise3D), PETG (PolyethyleneTerephthalate Glycol) (Raise3D), ASA (Acrylonitrile Styrene Acrylate) (Raise3D), PC (Polycarbonate) (Raise3D), TPU (Thermoplastic polyurethane)-95 (Raise3D), PLA Copper (Gizmodorks), PP (Polypropylene) (Braskem), and HIPS (High Impact Polystyrene) (Gizmodorks). Testing also quantified the spectral impact of using different color 3D printed surfaces in a growth chamber. The material used for spectral testing was PLA. Printing employed a standard surface texture representative of all materials. It was shown through Tensile Testing (ASTM D638-22) that the breaking force of a 3D printed part greatly varied depending on layer orientation. This is common through all materials, and demonstrates that the strength of a 3D printed component can be maximized by layering the material normal to the primary force on the part. Four-point flexural testing (ASTM D790) provided quantities of interest, Flexural modulus, Flexural strength, Flexural stress, and strain at break within a 5% strain limit from each of nine materials. Biofilm formation testing was conducted in the Molecular and Microbiological Laboratory. Testing completed on specimens from each material showed equal formation on the surface. Additional plant growth testing was conducted in the PPA beyond the initial germination testing. The final assessment documents that three materials (PLA, ABS, and PC) have reached TRL 6 through extensive testing, and ultimate end-to-end applied use in experimental or testing conditions (flight and ground). TRL 5 materials (ASA, TPU-95, PLA Copper, PP, PETG, and HIPS) have all been successfully applied in Research and Development for crop growth applications and are ready to be applied in formal testing. TRL 4 materials Nylon910, PLA Carbon Fiber, PPA CF, PPA Glass Fiber (GF), NinjaFlex, and P-filament 721 are materials that were able to be printed and tested, but have yet to show data meeting applied requirements. TRL 3 NylonX, Flex TPE-185, and Nylon were unable to be reliably printed to fulfill testing. These results provide researchers with reference for materials to use during plant growth experimentation, and also set a standard for future characterization work applying 3D printing and materials to testing, research, and experimentation.

Gioia Massa↗
DOE OSTI2020

Black-Box Optimization for Design of Concentrating Solar Power and Photovoltaic Hybrid Systems with Optimal Dispatch Decisions

The hybridization of concentrating solar power (CSP) and photovoltaics (PV) can enable dispatchable renewable electricity generation at a lower price than current stand-alone CSP systems. However, designing a CSP-PV hybrid system can be challenging because of the many degrees of freedom in design that affect the internal and external system interactions and trade-offs. We develop a methodology to determine optimal designs for CSP-PV hybrids by implementing NLopt's derivative-free, or “black-box,” algorithms around pre-existing CSP-PV hybrid simulation software that utilizes the National Renewable Energy Laboratory’s System Advisor Model (SAM); we then employ a dispatch optimization model to determine operational decisions that maximize a plant’s profits. We present optimal designs for CSP-PV hybrid systems dispatching against four time-of-delivery (ToD) pricing structures. NLopt’s algorithms can improve the base case design’s power purchase agreement (PPA) price by 15% to 21%, depending on the ToD pricing structure. In addition, we present the resulting optimal CSP-PV hybrid design’s annual performance metrics, which tend to have capacity factors between 50% and 62%, but are able to generate electricity during the year’s highest-valued periods about 90% of the time. Lastly, we investigate the trade-offs between capacity factor and PPA price using Pareto fronts and demonstrate that, for some ToD pricing structures, the system capacity factor can increase by 20% but at the expense of a 2% increase in PPA price.

black-box↗
NASA NTRS1993

Oligomerization reactions of ribonucleotides - The reaction of the 5'-phosphorimidazolide of adenosine with diadenosine pyrophosphate on montmorillonite and other minerals

The overall regiospecificity of the 3',5'-phosphodiester bond formation is shown to be increased from 64 to 83 percent when a 9:1 ratio of ImpA to A5'ppA instead of ImpA alone is reacted in the presence of Na(+)-montmorillonite. The major factor in the regiospecificity increase is the formation of 3',5'-linked A5'ppA3'pA and A5'pp-A3'pA3'pA. The results obtained show that ImpA reacts more readily with A5'ppA than it does with another ImpA molecule and that A5'ppA plays a central role in directing the formation of 3',5'-phosphodiester bonds.

Ferris, James P.↗
NASA NTRS2009

Pulsed Plasma Accelerator Modeling

This report presents the main results of the modeling task of the PPA project. The objective of this task is to make major progress towards developing a new computational tool with new capabilities for simulating cylindrically symmetric 2.5 dimensional (2.5 D) PPA's. This tool may be used for designing, optimizing, and understanding the operation of PPA s and other pulsed power devices. The foundation for this task is the 2-D, cylindrically symmetric, magnetohydrodynamic (MHD) code PCAPPS (Princeton Code for Advanced Plasma Propulsion Simulation). PCAPPS was originally developed by Sankaran (2001, 2005) to model Lithium Lorentz Force Accelerators (LLFA's), which are electrode based devices, and are typically operated in continuous magnetic field to the model, and implementing a first principles, self-consistent algorithm to couple the plasma and power circuit that drives the plasma dynamics.

Goodman, M.↗
NASA NTRS2010

Photometer Performance Assessment in Kepler Science Data Processing

This paper describes the algorithms of the Photometer Performance Assessment (PPA) software component in the science data processing pipeline of the Kepler mission. The PPA performs two tasks: One is to analyze the health and performance of the Kepler photometer based on the long cadence science data down-linked via Ka band approximately every 30 days. The second is to determine the attitude of the Kepler spacecraft with high precision at each long cadence. The PPA component is demonstrated to work effectively with the Kepler flight data.

Li, Jie↗
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 NTRS2014

An Approach for Hydrogen Recycling in a Closed-loop Life Support Architecture to Increase Oxygen Recovery Beyond State-of-the-Art

State‐of‐the‐art atmosphere revitalization life support technology on the International Space Station is theoretically capable of recovering 50% of the oxygen from metabolic carbon dioxide via the Carbon Dioxide Reduction Assembly (CRA). When coupled with a Plasma Pyrolysis Assembly (PPA), oxygen recovery increases dramatically, thus drastically reducing the logistical challenges associated with oxygen resupply. The PPA decomposes methane to predominantly form hydrogen and acetylene. Because of the unstable nature of acetylene, a down‐stream separation system is required to remove acetylene from the hydrogen stream before it is recycled to the CRA. A new closed‐loop architecture that includes a PPA and downstream Hydrogen Purification Assembly (HyPA) is proposed and discussed. Additionally, initial results of separation material testing are reported.

Abney, Morgan B.↗
NASA NTRS2015

Increased Oxygen Recovery from Sabatier Systems Using Plasma Pyrolysis Technology and Metal Hydride Separation

State-of-the-art life support carbon dioxide (CO2) reduction technology is based on the Sabatier reaction where less than 50% of the oxygen required for the crew is recovered from metabolic CO2. The reaction produces water as the primary product and methane as a byproduct. Oxygen recovery is constrained by the limited availability of reactant hydrogen. This is further exacerbated when Sabatier methane (CH4) is vented as a waste product resulting in a continuous loss of reactant hydrogen. Post-processing methane with the Plasma Pyrolysis Assembly (PPA) to recover hydrogen has the potential to dramatically increase oxygen recovery and thus drastically reduce the logistical challenges associated with oxygen resupply. The PPA decomposes methane into predominantly hydrogen and acetylene. Due to the highly unstable nature of acetylene, a separation system is necessary to purify hydrogen before it is recycled back to the Sabatier reactor. Testing and evaluation of a full-scale Third Generation PPA is reported and investigations into metal hydride hydrogen separation technology is discussed.

Zachary W Greenwood↗