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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 487 records · Page 27
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

The Road Ahead for Metal–Organic Frameworks: Current Landscape, Challenges and Future Prospects

This perspective highlights the transformative potential of Metal–Organic Frameworks (MOFs) in environmental and healthcare sectors. It discusses work that has advanced beyond technology readiness levels of >4 including applications in capture, storage, and conversion of gases to value added products. This work showcases efforts in the most salient applications of MOFs which have been performed at a great cadence, enabled by the federal government, large companies, and startups to commercialize these technologies despite facing significant challenges. This article also forecasts the role of nanoscale MOFs in healthcare, including strides toward personalized medicine, advocating for their use in custom-tailored drug delivery systems. Lastly, we underscore the potential acceleration in MOF research and development through the integration of machine learning and AI, positioning MOFs as versatile tools poised to address global sustainability and health challenges.

atmospheric chemistry↗
DOE OSTI2021

Chemical Kinetics of the Autoxidation of Poly(ethylenimine) in CO 2 Sorbents

The oxidative degradation rates of a CO 2 sorbent composed of a mesoporous alumina impregnated with poly- (ethylenimine) (PEI) are measured under systematically varied conditions and a reaction rate law is created. Good agreement is shown between the rate of oxidation obtained via in situ calorimetric heat measurement during oxidative degradation reactions and the loss of CO 2 capture performance presented as amine efficiency (mol CO 2 /mol amine). PEI mass loss and elemental composition are tracked over the course of the reaction and used in conjunction with the oxidation rate measurements to shed insight into the oxidation reaction(s). These data, in combination with measurements of the heat of reaction, suggest a common reaction set across the range of temperatures, oxygen concentrations, and sorbent compositions tested. The data are consistent with the basic autoxidation scheme (BAS), the accepted mechanism of autoxidation of aliphatic polymers. We propose a lumped kinetic model to describe the oxidation reaction set and estimate an activation energy of 105 kJ/mol and an oxygen reaction order of 0.5–0.7 from the data accordingly. Furthermore, these parameters can be incorporated into process cycle models to estimate the material lifetime, a critical uncertainty in the deployment of DAC technologies.

36 MATERIALS SCIENCE↗
DOE OSTI2024

CO 2 Uptake and Stability Enhancement in Vinyltrimethoxysilane‐Treated SBA‐15 Solid Amine‐Based Sorbents

Abstract Silica‐supported amine absorbents, including materials produced by tethering aminosilanes or infusion of poly(ethyleneimine), represent a promising class of materials for CO 2 capture applications, including direct air and point source capture. Various silica surface treatments and functionalization strategies are explored to enhance stability and CO 2 uptake in amine‐based solid sorbent systems. Here, the synthesis and characterization of novel vinyltrimethoxysilane‐treated Santa Barbara Amorphous‐15 (SBA‐15) supports and the corresponding enhancement in CO 2 uptake compared to various SBA‐15‐based control supports are presented. The relationship between CO 2 diffusion and amine efficiency in these systems is explored using a previously reported kinetic model. The synthesized materials are characterized with CO 2 and H 2 O isotherms, diffuse reflectance infrared Fourier transform spectroscopy, 1 H T 1 – T 2 relaxation correlation NMR, and rapid thermal cycling experiments. The novel support materials are shown to enable high amine efficiencies, approaching a fourfold improvement over standard SBA‐15‐supported amines, while simultaneously exhibiting excellent stability when cycled rapidly under humid conditions. As the poly(ethyleneimine) loadings are held constant across the various samples, enhancements in CO 2 uptake are attributed to differences in the way the poly(ethyleneimine) interacts with the support surface.

Vallace, Anthony↗
DOE OSTI2025

Supported ionic liquid membranes (SILMs) with exceptional selectivity and permeability for dilute CO 2 separations

Supported ionic liquid membranes (SILMs), containing phosphonium ionic liquids with aprotic N-heterocyclic anions (AHA ILs) in an inert inorganic support, were tested under both dry and humidified (40 % RH) mixed-gas conditions down to 420 ppm CO 2 in N 2 at 35 °C. In the dry case, the best performing IL, triethyl(octyl)phosphonium 4-bromopyrazolide ([P 2228 ][4-BrPyra]) exhibited mixed-gas CO 2 permeabilities and CO 2 /N 2 permeability selectivities as high as 26,800 barrer and 7,000, respectively. In the presence of humidity, the CO 2 permeability and CO 2 /N 2 selectivity increased to 49,100 barrer and 13,200, respectively, and these are the highest reported combination in the literature. Humidity amplifies CO 2 permeabilities and CO 2 /N 2 permeability selectivities through increases in CO 2 capacity due to bicarbonate formation and through faster mobility of the mobile carrier from decreased viscosity. Furthermore, N 2 permeability stayed roughly invariant in the presence of humidity, likely from competing effects of viscosity reduction and lower N 2 solubility.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2024

Navigating the obstacles of carbon-negative technologies

Nine years after the Paris Agreement was adopted, it is clear that negative-emission technologies are required to keep 1.5°C, or even 2°C, of global warming in reach. Yet carbon dioxide removal (CDR) strategies remain rife with political, technical, economic, environmental, and geographic challenges. Here, this Voices surveys the pitfalls of incorporating carbon-negative technologies into climate mitigation plans and asks: how can we navigate around the challenges to make CDR a reliable component of climate mitigation?

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2026

The Effects of Iron and Manganese Doping on the Carbonation of Brucite [Mg(OH) 2 ]

Brucite [Mg(OH) 2 ] is a promising sorbent for carbon dioxide removal (CDR) due to its availability and low calcination temperatures. However, natural and synthetic brucites tend to contain metal impurities, such as iron or manganese, and how these impurities affect the interfacial chemical reactivity is uncertain. Here, in this study, the impact of low concentrations of iron and manganese impurities on the carbonation efficiency of Mg(OH) 2 was examined. Mg(OH) 2 with small amounts (1–5 mol %) of Fe and Mn was synthesized. The increasing substitution of Fe into Mg(OH) 2 was accompanied by the oxidation of Fe. The phase transformation sequence during the carbonation was found to be brucite [Mg(OH) 2 ] → amorphous magnesium carbonate (MgCO 3 ·nH 2 O) → nesquehonite (MgCO 3 ·3H 2 O), regardless of impurity concentration. Both the Fe- and Mn-doped Mg(OH) 2 samples were more reactive than endmember Mg(OH) 2 , possibly due to their higher surface areas and lower stabilities. During carbonation, 3 mol % Fe- and Mn-doped Mg(OH) 2 showed the highest reactivity. The variance in reactivity for Mn-doped Mg(OH) 2 was less than that of Fe-doped Mg(OH) 2 . These results suggest that natural or industrial waste Mg(OH) 2 with less than 5 mol % Fe and Mn impurities may be targeted as more effective CDR sorbents than endmember Mg(OH) 2 .

Carbon dioxide removal↗
DOE OSTI2025

Nuclear Reactor Heat Extraction for Synthetic Fuel Plants

This report looks at the viability and best approach when producing synthetic fuels using heat and power supplied by advanced nuclear energy systems. The report looks at a low temperature integration pathway with four types of advanced reactors: a pressurized water reactor (PWR), an advanced light water reactor (A-LWR), a sodium fast reactor (SFR), and a high-temperature gas-cooled reactor (HTGR). A failure modes and effects analysis (FMEA) of the coupling system between the nuclear plant and the synthetic fuel systems is performed with the goal of identifying the reliability of such a thermal delivery system. Furthermore, a high temperature pathway is investigated for synfuel coupling to determine if this is more efficient and more cost effective as a coupling approach.

10 - SYNTHETIC FUELS↗
NASA NTRS1998

Strutjet Matures to Support Propulsion Needs in the 2000+ World

The Strutjet, Aerojet's Rocket Based Combined Cycle (RBCC) concept, was discussed in a previous ISABE paper as an enabling propulsion concept for single stage to orbit applications. This paper describes the technical progress of the Strutjet since 1996 together with a rationale why RBCC engines in general and the Strutjet in particular, lend themselves uniquely to systems having the ability to expand current space and also open new global "rapid delivery" markets. In particular, the paper substantiates the claims why for certain missions RBCC powered vehicles can be operated at higher margins than all rocket systems, and why within the family of conceivable RBCC systems the Strutjet excels due to its unique architecture and design features. A special emphasis is given to the selection of the engine's ram/scram mode design point because only that mode can add significantly to the mission effective Isp. The thrust produced by an airbreathing engine is directly related to the mass of air processed. This air is captured by the inlet and compressed to raise the pressure for combustion and subsequent expansion. The net accelerating force is the difference between the gross thrust and total vehicle drag (including the spill drag). This total drag is highest at low speeds when the gross thrust is lowest. When the net accelerating force is low, most of the fuel burned is wasted overcoming the vehicle drag. Higher thrust is necessary to perform the mission. One method is to leave the rockets on longer but this results in much higher propellant consumption.

Siebenhaar, A.↗
NASA NTRS2014

Amine Swingbed Payload Testing on ISS

One of NASA/Johnson Space Center's test articles of the amine-based carbon dioxide (CO2) and water vapor sorbent system known as the CO2 And Moisture Removal Amine Swing-bed, or CAMRAS, was incorporated into a payload on the International Space Station (ISS). The intent of the payload is to demonstrate the spacecraft-environment viability of the core atmosphere revitalization technology baselined for the new Orion vehicle. In addition to the air blower, vacuum connection, and controls needed to run the CAMRAS itself, the payload incorporates a suite of sensors for scientific data gathering, a water save function, and an air save function. The water save function minimizes the atmospheric water vapor reaching the CAMRAS unit, thereby reducing ISS water losses that are otherwise acceptable, and even desirable, in the Orion environment. The air save function captures about half of the ullage air that would normally be vented overboard every time the cabin air-adsorbing and space vacuum-desorbing CAMRAS beds swap functions. The JSC team conducted 1000 hours of on-orbit Amine Swingbed Payload testing in 2013. This paper presents the basics of the payload's design and history, as well as a summary of the test results, including comparisons with prelaunch testing.

Button, Amy↗
NASA NTRS2014

Amine Swingbed Payload Testing on ISS

One of NASA Johnson Space Center's test articles of the amine-based carbon dioxide (CO2) and water vapor sorbent system known as the CO2 And Moisture Removal Amine Swing-bed, or CAMRAS, was incorporated into a payload on the International Space Station (ISS). The intent of the payload is to demonstrate the spacecraft-environment viability of the core atmosphere revitalization technology baselined for the new Orion vehicle. In addition to the air blower, vacuum connection, and controls needed to run the CAMRAS, the payload incorporates a suite of sensors for scientific data gathering, a water save function, and an air save function. The water save function minimizes the atmospheric water vapor reaching the CAMRAS unit, thereby reducing ISS water losses that are otherwise acceptable, and even desirable, in the Orion environment. The air save function captures about half of the ullage air that would normally be vented overboard every time the cabin air-adsorbing and space vacuum-desorbing CAMRAS beds swap functions. The JSC team conducted 1000 hours of on-orbit Amine Swingbed Payload testing in 2013 and early 2014. This paper presents the basics of the payload's design and history, as well as a summary of the test results, including comparisons with prelaunch testing.

Button, Amy B.↗
DOE OSTI2021

Updated weather model captures subtleties of cold-air pool events

Imagine cold air building up inside a valley or other topographic basin, like a cold swimming pool in the atmosphere. Known in meteorology as cold-air pools, or simply cold pools, these events affect wind plant power production in two key ways. Because they are associated with stagnant air and low winds near the ground, cold pools can severely limit wind energy output over periods of hours to days. Then, when cold pools dissolve, known as cold pool “erosion,” increased wind speeds allow wind power production to recover.

Energy↗
DOE OSTI2024

Daytime cooling efficiencies of urban trees derived from land surface temperature are much higher than those for air temperature

Accurately capturing the impact of urban trees on temperature can help optimize urban heat mitigation strategies. Recently, there has been widespread use of remotely sensed land surface temperature (T s ) to quantify the cooling efficiency (CE) of urban trees. However, remotely sensed T s reflects emitted radiation from the surface of an object seen from the point of view of the thermal sensor, which is not a good proxy for the air temperature (T a ) perceived by humans. The extent to which the CEs derived from T s reflect the true experiences of urban residents is debatable. Therefore, this study systematically compared the T s -based CE (CE T s ) with the T a -based CE (CE T a ) in 392 European urban clusters. CE T s and CE T a were defined as the reductions in T s and T a , respectively, for every 1% increase in fractional tree cover (FTC). The results show that the increase in FTC has a substantial impact on reducing T s and T a in most cities during daytime. However, at night, the response of T s and T a to increased FTC appears to be much weaker and ambiguous. On average, for European cities, daytime CE T s reaches 0.075 °C % -1 , which is significantly higher (by an order of magnitude) than the corresponding CE T a of 0.006 °C % -1 . In contrast, the average nighttime CE T s and CE T a for European cities are similar, both approximating zero. Overall, urban trees can lower daytime temperatures, but the magnitude of their cooling effect is notably amplified when using remotely sensed T s estimates compared to in situ T a measurements, which is important to consider for accurately constraining public health benefits. Our findings provide critical insights into the realistic efficiencies of alleviating urban heat through tree planting.

54 ENVIRONMENTAL SCIENCES↗
NASA NTRS2017

Young People's Burden: Requirement of Negative CO2 Emissions

Global temperature is a fundamental climate metric highly correlated with sea level, which implies that keeping shorelines near their present location requires keeping global temperature within or close to its preindustrial Holocene range. However, global temperature excluding short-term variability now exceeds +1 C relative to the 1880 - 1920 mean and annual 2016 global temperature was almost +1.3 C. We show that global temperature has risen well out of the Holocene range and Earth is now as warm as it was during the prior (Eemian) interglacial period, when sea level reached 6 - 9 m higher than today. Further, Earth is out of energy balance with present atmospheric composition, implying that more warming is in the pipeline, and we show that the growth rate of greenhouse gas climate forcing has accelerated markedly in the past decade. The rapidity of ice sheet and sea level response to global temperature is difficult to predict, but is dependent on the magnitude of warming. Targets for limiting global warming thus, at minimum, should aim to avoid leaving global temperature at Eemian or higher levels for centuries. Such targets now require "negative emissions", i.e., extraction of CO2 from the air. If phasedown of fossil fuel emissions begins soon, improved agricultural and forestry practices, including reforestation and steps to improve soil fertility and increase its carbon content, may provide much of the necessary CO2 extraction. In that case, the magnitude and duration of global temperature excursion above the natural range of the current interglacial (Holocene) could be limited and irreversible climate impacts could be minimized. In contrast, continued high fossil fuel emissions today place a burden on young people to undertake massive technological CO2 extraction if they are to limit climate change and its consequences. Proposed methods of extraction such as bioenergy with carbon capture and storage (BECCS) or air capture of CO2 have minimal estimated costs of USD 89 - 535 trillion this century and also have large risks and uncertain feasibility. Continued high fossil fuel emissions unarguably sentences young people to either a massive, implausible cleanup or growing deleterious climate impacts or both.

Hansen, James↗
DOE OSTI2024

The Impact of Cement Plant Air Ingress on Membrane-Based CO2 Capture Retrofit Cost

This PowerPoint presentation summarizes the cost and performance results of the techno-economic analysis of membrane-based carbon capture retrofits at cement plants, published in June 2024, titled “The Impact of Cement Plant Air Ingress on Membrane-Based CO2 Capture Retrofit Cost.” The analysis report used as a basis for slide contents was developed by NETL for publication in the scientific journal Carbon Capture Science and Technology.

Hughes, Sydney↗
DOE OSTI2024

The Impact of Cement Plant Air Ingress on Membrane-Based CO2 Capture Retrofit Cost

This PowerPoint presentation summarizes the cost and performance results of the techno-economic analysis of membrane-based carbon capture retrofits at cement plants, published in June 2024, titled “The Impact of Cement Plant Air Ingress on Membrane-Based CO2 Capture Retrofit Cost.” The analysis report used as a basis for slide contents was developed by NETL for publication in the scientific journal Carbon Capture Science and Technology.

Hughes, Sydney↗