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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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All sourcesNASA NTRSDOE OSTI
NASA NTRS1952

Analysis of a Pneumatic Probe for Measuring Exhaust-Gas Temperatures with Some Preliminary Experimental Results

A pneumatic probe based on continuity of mass flow through two restrictions separated by a cooling chamber was constructed to measure gas temperature at and beyond the limit of thermocouples. This probe consisted of a subsonic flat-plate orifice for the first restriction and a sonic-flow converging-diverging nozzle for the second restriction. The effect of variation in gas constants on the calibration is examined for common engine-exhaust gases. A high-temperature wind tunnel that allowed calibration of the probe at temperatures up to 2000 deg R and. Mach numbers up to 0.8 is described. Agreement to better than 30 deg R between pneumatic probe indication and the indication of a rake of radiation shielded thermocouples indicates that extrapolation of the calibration to higher temperatures is possible with fair accuracy

Scadron, Marvin D.↗
NASA NTRS1997

Adsorption and Processes in Spacecraft Environmental Control and Life Support Systems

The environmental control and life support system on a spacecraft must maintain a safe and comfortable environment in which the crew can live and work. The system's functions include supplying the crew with oxygen and water, as well as removing carbon dioxide, water vapor, and trace contaminants from cabin air. Although open-loop systems have been used in the past, logistics and safety factors of current and future missions in space make near-complete recycling of the cabin's air and water desirable. The recycling process may include separation and reduction of carbon dioxide, removal of trace gas-phase contaminants, recovery and purification of humidity condensate, purification and polishing of wastewater streams, and other processes. Several of these operations can be performed totally or in part by adsorption processes. Adsorption processes are frequently good candidates for separation and purification in space by virtue of such characteristics as gravity independence, high reliability, relatively high energy efficiency, design flexibility, technological maturity, and regenerability. For these reasons, adsorption has historically played a key role in life support on U.S. and Russian piloted spacecraft. This article focuses on three current spacecraft life support applications that often use adsorption technology: carbon dioxide separation from cabin air, gas-phase trace contaminant control, and potable water recovery from waste streams. In each application, adsorption technology has been selected for use on the International Space Station. The requirements, science, and hardware for each application are discussed. Eventually, human space exploration may lead to construction of planetary habitats. These habitats may have additional applications, such as control of greenhouse gas composition and purification of hydroponic solutions, and may have different requirements and resources available to them, such as gases present in the planetary atmosphere. Adsorption separation and purification processes may continue to fulfill environmental control and life support needs well into the future.

Dall-Bauman, Liese↗
DOE OSTI2021

Dynamic in situ imaging of methane hydrate formation in coal media

Fast 3D X-ray imaging has proved to provide crucial insights into multi-phase dynamic processes in various geomaterials. In particular, many in situ imaging experiments have been made to study gas-hydrate formation in porous sandy samples. Such imaging is challenging for the methane gas-hydrate formation in coal samples because of the coal micro-porosity structure and lower X-ray contrast. Here we present results of the first dynamic in situ micro-computed tomography experiment of methane-hydrate formation in coal samples. Synchrotron phase-contrast tomography techniques allowed to achieve necessary contrast levels to separate all the materials of interest (gas, water, coal, and gas hydrate) in reconstructed images with high spatial and temporal resolution. The imaging results are compared to the ones from a similar tomographic experiment with sand samples. Methane-hydrate formation is accompanied by the water movements caused by cryogenic water suction that happens in sequences of short fast movements with longer equilibrium states in between. Only one type of the hydrate formation was observed in coal (growth as shells on grain boundaries) as opposed to three types in sand (shells, growth into gas pockets, and inside water volumes). In particular, this leads to a slower hydrateformation speed in coal. For the coal sample, we also observed water extraction from grains, and interpreted it as competitive sorption of methane. Lastly, we visualized the dynamic behavior of this water extraction via microchannels inside the coal grains, and performed nano-tomography imaging of these channels for a better understanding of this phenomenon.

58 GEOSCIENCES↗
NASA NTRS1977

Planetary noble gas components in Orgueil

In the reported investigation, the approach employed by Jeffery and Anders (1970) and Eberhardt (1974), who used colloidal suspensions in separating minerals of the Orgueil carbonaceous chondrite (C1), was extended to an application involving the enrichment of a planetary noble gas carrier in several C1 and C2 meteorites. The thermal release pattern of Orgueil 'carbon' is considered, taking into account elemental effects, a comparison of noble gas release from 'carbon' separates and bulk meteorite samples, isotopic effects, and a comparison with Murray 'carbon'. An evaluation is conducted of the noble gas components in carbonaceous chondrites. The origin of primordial noble gases in carbonaceous chondrites is also discussed, giving attention to the origin of solar gases, the role of 'carbon' as the novel vehicle for planetary gases, and plausible astrophysical sites for the production of anomalous krypton and xenon.

Frick, U.↗
NASA NTRS1987

Corona anemometry for qualitative measurement of reversing surface flow with application to separation control by external excitation

An corona anemometer which detects gas flow by the displacement of an ion beam is described, and experiments are performed using the anemometer to investigate the active control of diffusor separation by periodic forcing. The apparatus is applied to the separated flow over a rearward facing ramp. An oscillating vane is attached to the surface near the separation point. It is suggested that the enhancement in turbulent energy produced by the oscillating vane is due to drastic modification of the wake shear flow, and not to vane-produced turbulence.

Durbin, P. A.↗
DOE OSTI2019

Recent developments on polymeric membranes for CO 2 capture from flue gas

Polymeric membranes have been widely considered as one of the next-generation technologies for CO 2 capture from fossil fuel-derived flue gases. This separation modality requires novel polymeric materials that possess efficient CO 2 /N 2 separation properties, as well as chemical and mechanical stability for a multiyear membrane lifetime. In this paper, recent developments in polymeric membranes tailored for post-combustion carbon capture are reviewed. The selected polymeric materials encompass ether oxygen-rich polymers, polynorbornenes, ionic liquid membranes, and facilitated transport membranes. In each of the selected materials, noteworthy research efforts for material design and membrane formation are highlighted. The performances of the selected materials are compared in the CO 2 /N 2 selectivity-CO 2 permeance plot. As the only class of materials reviewed herein that have demonstrated the fabrication of thin-film composite membranes in scale, facilitated transport membranes have shown both high selectivity and permeance at relevant conditions for post-combustion carbon capture. Finally, comprehensive field tests are needed to resolve the technical gap between the material development and the commercial application.

20 FOSSIL-FUELED POWER PLANTS↗
NASA NTRS1994

Performance model of a recirculating stack nickel hydrogen cell

A theoretical model of the nickel hydrogen battery cell has been utilized to describe the chemical and physical changes during charge and overcharge in a recirculating stack nickel hydrogen cell. In particular, the movement of gas and electrolyte have been examined as a function of the amount of electrolyte put into the cell stack during cell activation, and as a function of flooding in regions of the gas screen in this cell design. Additionally, a two-dimensional variation on this model has been utilized to describe the effects of non-uniform loading in the nickel-electrode on the movement of gas and electrolyte within the recirculating stack nickel hydrogen cell. The type of nonuniform loading that has been examined here is that associated with higher than average loading near the surface of the sintered nickel electrode, a condition present to some degree in many nickel electrodes made by electrochemical impregnation methods. The effects of high surface loading were examined primarily under conditions of overcharge, since the movement of gas and electrolyte in the overcharging condition was typically where the greatest effects of non-uniform loading were found. The results indicate that significant changes in the capillary forces between cell components occur as the percentage of free volume in the stack filled by electrolyte becomes very high. These changes create large gradients in gas-filled space and oxygen concentrations near the boundary between the separator and the hydrogen electrode when the electrolyte fill is much greater than about 95 percent of the stack free volume. At lower electrolyte fill levels, these gaseous and electrolyte gradients become less extreme, and shift through the separator towards the nickel electrode. Similarly, flooding of areas in the gas screen cause higher concentrations of oxygen gas to approach the platinum/hydrogen electrode that is opposite the back side of the nickel electrode. These results illustrate the need for appropriate pore size distributions, and the maintenance of both convective electrolyte and gas flow paths through the stack, if the recirculating stack nickel hydrogen cell design is to work properly.

Zimmerman, Albert H.↗
NASA NTRS2020

Recover Gas from Liquids in Low Gravity

This document is the final report resulting from the work conducted by undergraduate students at the University of South Alabama during the 2019/2020 academic year. Currently, on the International Space Station a solid adsorbent material is used to remove CO 2 from cabin air; however, liquid absorbent/reactive based systems are appealing because they may offer greater CO 2 capture efficiency. When liquids are used to capture CO 2 a regeneration step is required to release the CO 2 from the fluid for subsequent processing. During regeneration aerosolized droplets of water and liquid amines are produced creating a 2-phase fluid stream. Because the CO 2 stream is to be sent to a Sabatier reactor for conversion into methane, the droplets of the water and amines must be removed, necessitating the need for a vapor/liquid separation process in a microgravity environment. This class was tasked with designing a system to separate the aerosolized droplets from the gas stream. An ionic liquid was assumed to be the amine based absorber fluid that was used to capture the CO 2 , which is a key assumption because the ionic liquid has vanishingly low vapor pressure. The lack of volatility of the ionic liquid eliminates the need to manage an aerosolized amine resulting in only an aerosolized water air separation. To solve this challenge an undergraduate class used systems engineering to design and construct a hydrophobic screen separation apparatus for a 2-phase, vapor/liquid flow. The apparatus was constructed, but initial testing was not possible due to the closure of the University labs due to the corona-virus pandemic.

T Grant Glover↗
NASA NTRS1993

Probing the extent and content of low ionization gas in galaxies: QSO absorption and HI emission

The small projected separations of some QSO's and low-redshift galaxies provide unique opportunities to study the extent and content of gas in galaxies through observation of absorption in the QSO spectra. Observations of these systems provide valuable information on the connection between the absorbing gas and the galaxy, as well as detailed information on the morphology and environment of the galaxy itself. While there is direct evidence that galaxies can produce the intervening-type QSO absorption lines, over the past decade, the study of such 'QSO-galaxy pairs' (at low redshift) has been considered unsuccessful because new detections of absorption were seldom made. A fundamental problem concerning the relation between these low-redshift systems and those seen at moderate to high redshift remains unresolved. Direct and indirect measures of galaxy absorption cross sections at moderate to high redshifts (z is approximately greater than 20.5) are much larger than the optical and HI sizes of local galaxies. However, direct comparison of the low and moderate to high redshift systems is difficult since different ions are observed in different redshift regimes. Observations are presented for a new sample of QSO-galaxy pairs. Nine new QSO's which shine through nearby galaxies (on the sky-plane) were observed to search for CaII absorption in the QSO spectra at the foreground galaxy redshifts.

Womble, Donna S.↗
DOE OSTI2024

Air separation and N 2 purification with Ba 0.15 Sr 0.85 FeO 3-$δ$ via a two-step thermochemical process

Thermochemical air separation to produce high-purity N 2 was demonstrated in a vertical tube reactor via a two-step reduction–oxidation cycle with an A-site substituted perovskite Ba 0.15 Sr 0.85 FeO 3–δ (BSF1585). BSF1585 particles were synthesized and characterized in terms of their chemical, morphological, and thermophysical properties. A thermodynamic cycle model and sensitivity analysis using computational heat and mass transfer models of the reactor were used to select the system operating parameters for a concentrating solar thermal-driven process. Thermal reduction up to 800 °C in air and temperature-swing air separation from 800 °C to minimum temperatures between 400 and 600 °C were performed in the reactor containing a 35 g packed bed of BSF1585. The reactor was characterized for dispersion, and air separation was characterized via mass spectrometry. Gas measurements indicated that the reactor produced N 2 with O 2 impurity concentrations as low as 0.02 % for > 30 min of operation. Additionally, a parametric study of air flow rates suggested that differences in observed and thermodynamically predicted O 2 impurities were due to imperfect gas transport in the bed. Temperature swing reduction/oxidation cycling experiments between 800 and 400 °C in air were conducted with no statistically significant degradation in N 2 purity over 50 cycles.

14 SOLAR ENERGY↗
DOE OSTI2024

SELF-HEALING PNEUMATIC ACTUATOR DIAPHRAGMS

In the oil and gas industry, damaged diaphragms in pneumatic actuators can lead to unintended methane leaks, increasing emissions. In this work, replacement self-healing diaphragms are manufactured for a commercial pneumatic actuator. To enable self-healing, hollow microvascular networks are created within the diaphragms using sacrificial 3D printed PLA w/ tin(II) oxalate. These microvascular networks are filled with healing chemistries and, upon damage, rupture. After rupturing, the healing chemistries mix and cure to “heal” the damage and reduce leaks. Separate actuator test stands using nitrogen gas and using natural gas were developed to assess the healing performance of diaphragms. A fatigue stand was also developed to evaluate the effects of the different microvascular network geometries on the fatigue life of diaphragms. Our results demonstrate self-healing in diaphragms subjected to damage and tested for leaks. In fatigue testing, our results indicate that the introduction of microvascular networks does not influence the fatigue life.

Self-healing, pneumatic actuator↗
DOE OSTI2021

Performance and flexibility improvements of Staged Pressurized Oxy-Combustion

Staged Pressurized Oxy-Combustion (SPOC) is a low-carbon coal combustion power technology being developed by Washington University in St. Louis (WUSTL). Oxy-combustion plants enable straightforward capture of carbon dioxide (CO 2 ) by removing most of the nitrogen in the combustion air prior to use, thereby burning fuel in near-pure oxygen instead of air, producing a flue gas containing primarily CO 2 and water. CO 2 capture at amounts > 90% is possible, often using cryogenic air separation. Oxy-combustion typically relies on flue gas recycle (FGR) to reduce the peak temperature and radiation that would otherwise occur in a fuel/oxygen only flame. SPOC reduces the peak temperatures of combustion by utilizing two or more pressurized boiler modules connected in series to produce fuel staging; hence, only a portion of the fuel is combusted in any given furnace module. This means that the thermal energy released at each stage can be captured and removed from the gases prior to subsequent stages, when more fuel is introduced. This allows the SPOC process to operate with minimal FGR, avoiding the associated efficiency losses and additional costs. Also, the process operates at an elevated gas-side pressure, reducing boiler size, enhancing heat transfer to achieve a compact boiler configuration as compared to an atmospheric-pressure boiler design, and allowing for recovery of the latent heat of the water from the flue gas at a temperature useful to the steam cycle. The resultant net efficiency of the system is over 3 percentage points greater than traditional atmospheric-pressure oxy-combustion, and 7 percentage points greater than the post combustion variant, representing a step-change improvement over first-generation capture technologies. To further develop the concept, WUSTL and the Electric Power Research Institute, Inc., organized a project with American Air Liquide, Inc., Doosan Babcock Limited, and the U.S. Department of Energy to investigate a practicable and workable boiler design. The team has identified the potential for enhanced process flexibility for controlling power generation over a wider load range than is normally available to conventional coal-fired power plants due to the staged nature of the heat release. With increasing intermittent renewable generator contribution, on-demand generators need to be highly flexible to participate in the future energy market, requiring extensive operation at reduced load. Conventional coal-fired steam generators typically face challenges in maintaining temperature control of the reheat steam and main steam at reduced loads. This results in inefficient operation, both in terms of the boiler efficiency and steam turbine heat rate. The results of this project show the SPOC process is capable of exceptional turndown, both on a stage basis and with the ability to bypass entire stages. Oxygen-supply flexibility was also investigated, as this is also a key consideration for the overall flexibility of the SPOC process given the operating constraints of conventional air separation units. A boiler design concept assessment was conducted and was focused on delivering compact and constructible design. The assessment checked appropriate tube operating metal temperatures at full load and at lower operating loads, balanced against the needs of efficient coal combustion, and the resultant slagging and ash environments. Combustion testing in the 100-kWth pressurized combustion test rig at WUSTL was carried out to validate the combustion, heat flux profiles and burnout at multiple loads. Combustion parameters investigated were flame stability, fuel burnout, ash composition, radiative heat flux, and temperature profiles. The results of these tests formed the basis of a full-scale boiler design that will encompass improvements in both efficiency and flexibility over conventional oxy-combustion processes. The air separation unit flexibility was investigated, and associated cost implications were addressed. Detailed economic assessment results for a 550 MWe net power block are also provided, allowing for a comparison against the baseline NETL oxy-combustion and post combustion capture cases.

20 FOSSIL-FUELED POWER PLANTS↗
NASA NTRS1993

Velocity resolved spectroscopy of molecular hydrogen emission in NGC6240

NGC6240 is a member of the class of luminous galaxies which emit a significant fraction of their total light in the infrared. Based on its highly disturbed morphology, Fosbury and Wall (1979) suggested that the system may be a merger of two gas rich galaxies. It has two nuclei separated by 2 arcsec which are visible in the near infrared and at radio wavelengths and CO observations show that the galaxy contains a large mass of molecular gas. Unusually strong H2 emission lines dominate the near infrared spectrum of this galaxy. The galaxy emits approximately 4x10(exp 7) solar luminosity in the 2.12 micron v = 1 to 0 S(1) line alone, an order of magnitude more than other merging or starburst galaxies. To provide a better understanding of the physical processes responsible for the H2 emission from NGC6240 we have begun a program to obtain high spectral resolution observations using the echelle in CGS4 on the UKIRT. Preliminary data which were obtained in February 1991 are presented here. It is intended to obtain further observations with twice the spatial and spectral resolution in June of this year.

Wright, G. S.↗
DOE OSTI2022

Thermodynamic modeling of adsorption at the liquid-solid interface

Adsorptive separation techniques are significantly energy efficient in comparison to conventional thermal separation techniques such as distillation. Despite extensive research and development activities undertaken for mixed-gas adsorption, the use of adsorption techniques for the separation of multicomponent liquid mixtures is still limited. A major barrier is the lack of accurate adsorption thermodynamic models, which form the scientific foundation of process simulation of such systems, making the translation to industrial scale challenging. In this work, we have rigorously computed the surface excess of adsorption for six binary liquid mixtures on silica gel at 303 K using the frameworks of the generalized Langmuir isotherm (gL) and the adsorbed solution theory (AST). The six binary liquid mixtures were formed by the pair-wise combinations of four components: benzene, 1,2-dichloroethane, cyclohexane, and n-heptane. We have based our calculations by considering simultaneous equilibria of three phases: saturated vapor phase, bulk liquid phase, and adsorbed phase. Further, the composition of the corresponding saturated vapor phase was estimated by the Nonrandom Two-Liquid activity coefficient model and experimental vapor-liquid equilibria data. The activity coefficients of the adsorbed phase, the central issue of multicomponent adsorption thermodynamics, were calculated using the adsorption Nonrandom Two-Liquid activity coefficient model. Devoid of simplifying assumptions, gL and AST provide rigorous thermodynamic frameworks for adsorption equilibria of multicomponent liquid mixtures.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS1979

Parametric study of potential early commercial MHD power plants

Three different reference power plant configurations were considered with parametric variations of the various design parameters for each plant. Two of the reference plant designs were based on the use of high temperature regenerative air preheaters separately fired by a low Btu gas produced from a coal gasifier which was integrated with the power plant. The third reference plant design was based on the use of oxygen enriched combustion air preheated to a more moderate temperature in a tubular type metallic recuperative heat exchanger which is part of the bottoming plant heat recovery system. Comparative information was developed on plant performance and economics. The highest net plant efficiency of about 45 percent was attained by the reference plant design with the use of a high temperature air preheater separately fired with the advanced entrained bed gasifier. The use of oxygen enrichment of the combustion air yielded the lowest cost of generating electricity at a slightly lower plant efficiency. Both of these two reference plant designs are identified as potentially attractive for early MHD power plant applications.

Hals, F. A.↗
DOE OSTI2020

Task 12 PV Sustainability - Environmental Life Cycle Assessment of Residential PV and Battery Storage Systems

Using a life cycle assessment (LCA), the environmental impacts from generating 1 kWh of electricity for self-consumption via a photovoltaic-battery system are determined. The system includes a 10 kWp multicrystalline-silicon photovoltaic (PV) system (solar irradiation about 1350 kWh/m2/year and annual yield 1000 kWh/kWp), an iron phosphate lithium-ion (LiFePO4) battery, and other components such as the control system, battery housing, and two inverters (one for the PV system and one for the battery system). Three options for the AC-coupled system with changing battery capacities (5, 10, or 20 kWh nominal capacity) are investigated. The environmental impacts are assessed using the indicators greenhouse gas emissions and cumulative energy demand (separated into total and non-renewable cumulative energy demand). In addition, the four most important impact categories for PV electricity - respiratory inorganics (particulate matter), acidification, energy carrier resource use, and minerals and metals resource use - are assessed according to the environmental footprint (EF) method. Data are drawn from the DETEC data DQRv2:2018, recent literature, and product details provided by manufacturers. The results show larger environmental impacts of PV-battery systems with increasing battery capacity; for capacities of 5, 10, and 20 kWh, the cumulative greenhouse gas emissions from 1 kWh of electricity generation for self-consumption via a PV-battery system are 80, 84, and 88 g CO 2- eq/kWh, respectively. The cumulative greenhouse gas emissions of PV electricity consumed directly or fed into the grid are 54 g CO 2 -eq/kWh. The corresponding total cumulative energy demands are 5.27, 5.40, and 5.50 MJ oil-eq/kWh, with non-renewable energy carriers contributing 1.16, 1.22, and 1.29 MJ oil-eq/kWh. In the investigated EF impact categories, we similarly observe a larger environmental burden with increasing battery capacity, except in the use of minerals and metals. Our sensitivity analyses show that using a nickel cobalt manganese oxide (NCM) lithium-ion battery, instead of an LiFePO 4 battery, leads to a comparable environmental impact in terms of greenhouse gas emissions and cumulative energy demand. However, the NCM battery increases the impact in the EF categories of acidification and respiratory inorganics by 7 and 10%, respectively, whereas energy carrier resource use decreases by 4% and minerals and metals resource use decrease by 1%. Using a copper indium selenium (CIS) PV panel instead of a multicrystalline-silicon decreases greenhouse gas emissions by 24%, non-renewable cumulative energy demand by 13%, and particulate matter emissions by 60% (the largest decrease). Furthermore, the calculated environmental impacts are sensitive to the assumed battery lifetime. A decrease from 5000 to 3000 charge cycles increases non-renewable cumulative energy demand by 24% and greenhouse gas emissions by 16%. Increasing from 5000 to 7000 charge cycles decreases the environmental impacts by 6% and 7% in terms of non-renewable cumulative energy demand and greenhouse gas emissions, respectively. A utility-scale battery system case study shows that using batteries to store PV electricity overproduction reduces greenhouse gas emissions compared to using natural gas backup electricity generation.

14 SOLAR ENERGY↗
NASA NTRS1979

Sunspots and the physics of magnetic flux tubes. IX - Umbral dots and longitudinal overstability

The dynamical properties of the sunspot field and of a column of hot gas confined by such a vertical magnetic field are examined in order to understand the umbral dot within the context of the magnetic sunspot structure. Attention is given to the conditions necessary for gas intrusion, longitudinal as well as convective overstability, the growing modes, and the even mode. With the hypothesis that the subsurface magnetic field of a sunspot splits into many separate flux tubes with field-free gas between, it is suggested that the field-free columns occasionally punch their way up through the overlying magnetic field to the surface, appearing there as the bright, field-free umbral dots. Effects fostering the phenomenon are also discussed, that is, the enhanced temperature of a column of rising gas, the strongly reduced overhead magnetic pressure, and the initiated upward intrusion; these effects are illustrated with examples.

Parker, E. N.↗