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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 1,765 records · Page 98
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Solvent Polarity Independent Symmetry-Breaking Charge Separation in a Slip-Stacked Covalent Terrylene Monoimide Dimer

The design of organic materials capable of efficient photoinduced charge separation in low-polarity environments is a critical challenge for advancing organic photovoltaics. Symmetry-breaking charge separation (SB-CS) offers a promising route to efficient charge separation with minimal energy loss; however, in conventional organic materials this process typically relies on polar solvents to stabilize the charge-separated state. Here, we investigate a slip-stacked terrylene monoimide dimer (TMI 2 ) engineered with intrinsic electronic asymmetry to circumvent this limitation. We demonstrate through a comprehensive suite of ultrafast spectroscopic techniques that TMI 2 undergoes remarkably efficient SB-CS regardless of solvent polarity enabled by the permanent dipole moment of TMI and the accessible intramolecular charge-transfer (ICT) character of its monomer units. Furthermore, analysis of vibronic coherences reveals that the initial state mixing is actively driven by a 193 cm –1 intermolecular mode, while the final SB-CS state is marked by a distinct vibrational fingerprint of the radical ion pair product. Our findings reveal how the intrinsic electronic asymmetry of the TMI monomers that constitute TMI 2 creates an efficient charge separation pathway that precludes the need for external stabilization from a polar solvent. Here, this work establishes a powerful molecular design principle for leveraging intrinsic monomeric asymmetry to achieve efficient charge separation in low-dielectric environments, with significant implications for the development of next-generation organic optoelectronic materials.

Aromatic compounds↗
NASA NTRS2020

Bennu Shape Model Validation Methods and Results

The OSIRIS-REx Independent Shape Modeling Team, staffed by the Jet Propulsion Laboratory (JPL), has used stereophotoclinometry (SPC) to produce a three-dimensional shape model of Bennu. The SPC process is informed by (but is separate from) orbit determination, so it is important to ensure that the resulting shape model is consistent with all available spacecraft tracking data. Specifically, checking the shape model’s consistency with LIDAR measurements can illuminate any discrepancies, because LIDAR measurements are highly correlated with the shape model. This study focuses on the JPL experience with these LIDAR measurements and the greater context of the shape model validation process.

Lauretta, Dante S.↗
DOE OSTI2017

Performance Evaluations of Ion Exchanged Zeolite Membranes on Alumina Supports

This report describes the synthesis and evaluation of molecular sieve zeolite membranes to separate and concentrate tritiated water (HTO) from dilute HTO-bearing aqueous streams. In the first phase of this effort, several monovalent and divalent cation-exchanged silico alumino phosphate (SAPO-34) molecular sieve zeolite membranes were synthesized on disk supports and characterized with gas and vapor permeation measurements. In the second phase, Linde Type A (LTA) zeolite membranes were synthesized in disk and tubular supports. The pervaporation process performance was evaluated for the separation and concentration of tritiated water.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

System and method for the recycling of rare earth magnets

A system and a method for separating and recycling magnets made from rare earth elements from an article of manufacture used an alignment device to property position the rare earth magnet for processing. Once proper alignment is made, a separating device removes the magnet and a portion of the article. A heating device demagnetizes the magnets and vibration causes the magnets to separate from the portion of the article. Electromagnets remove the portion of the article and the rare earth magnets pass through for reclamation.

42 ENGINEERING↗
DOE OSTI2022

System and method for the recycling of rare earth magnets

A system and a method for separating and recycling magnets made from rare earth elements from an article of manufacture used an alignment device to property position the rare earth magnet for processing. Once proper alignment is made, a separating device removes the magnet and a portion of the article. A heating device demagnetizes the magnets and vibration causes the magnets to separate from the portion of the article. Electromagnets remove the portion of the article and the rare earth magnets pass through for reclamation.

McIntyre, Timothy J.↗
DOE OSTI2023

Lignin Derived Ionic Liquids: Synthesis and Application for Biopolymer Processing (CRADA Final Report)

We have established a scalable and economically viable process to convert lignin into ionic liquids for use in biopolymer processing. We have studied the four main topics: 1) lignin depolymerization to produce vanillin through oxidation, 2) lignin reduction to produce guaiacols, 3) oxidation process scale up, and 4) ionic liquid synthesis and application for biopolymer processing. The main accomplishment is summarized below: A maximal vanillin yield of 4.9% (8.8% total product yield) was achieved under optimal oxidation conditions using design of experiments (DOE); Aminophenol with 94.5% purity was synthesized via reductive amination using vanillin isolated from ion-exchange chromatography; At a higher lignin loading (10%), the vanillin yield in the scale up reaction was lower than the bench scale reaction; The filtration-based downstream separation of the scale-up process was able to recover 76% of vanillin; A maximal lignin reduction product (guaiacols) yield of 6.5% was achieved in the presence of Ru/C, formic acid, and methanol; The lignin reduction product yield and composition were affected by the use of different solvent and catalytic reagents (methanol in combination of Ru/C and formic acid gives the highest product yield); Lignin oxidation and reduction products: vanillin, acetovanillone, guaiacols, and eugenol are successfully used for IL synthesis; XX based ILs showed cellulose solubility with up to xx%; Technoeconomic analysis results indicate the potential of producing affordable ILs from kraft lignin (MSP: $14/kg); Life-cycle assessment results show the potential to reduce GHG emissions by up to 85% relative to existing ILs ([Ch][Lys]) with GHG emission: 1.2 kg CO 2e /kg of IL produced.

09 BIOMASS FUELS↗
DOE OSTI2016

A distributed cellulosic biorefinery system in the US Midwest based on corn stover

Corn stover supply chains in a distributed biorefinery system are explored here. The distributed cellulosic biorefinery uses pre-processed and densified cellulosic feedstock from a geographically separated facility (a depot) as raw material. A network of small-scale depot facilities supplies pre-processed feedstock to a distributed biorefinery. Depot facilities are assumed to be located at existing grain elevators, while distributed biorefineries are located adjacent to coal-fired power plants in areas with high gasoline consumption (urban areas) in the Midwest. The county level corn stover projections in 2022 by the US Billion-Ton Update report (2011) are used to estimate ethanol selling price and greenhouse gas (GHG) emissions of the ethanol fuel. The supply chain for each distributed biorefinery is determined by minimizing the ethanol selling price. Approximately ten distributed biorefineries based on corn stover could be established in the Midwest. Over 700 individual depot facilities participate in supplying the distributed biorefinery systems which collectively can produce greater than 12 hm3 of ethanol (3.3 billion gallons) per year. Ethanol selling price in the distributed system ranges from US$\$ $0.66 to US$\$ $1.03 per liter. Some distributed biorefineries are economically competitive with a centralized biorefinery. However, not every region can support a distributed biorefinery system due to inadequate corn stover availability. Cradle-to-gate GHG emissions of ethanol in the distributed systems are 22.1–46.6 g CO 2 per MJ. The external energy consumption in the depot facilities is the major GHG source. Optimizing process energy use in the depot facility is required to reduce both operation costs and GHG emissions.

09 BIOMASS FUELS↗
NASA NTRS2007

Scaling and Systems Considerations in Pulsed Inductive Thrusters

Performance scaling in pulsed inductive thrusters is discussed in the context of previous experimental studies and modeling results. Two processes, propellant ionization and acceleration, are interconnected where overall thruster performance and operation are concerned, but they are separated here to gain physical insight into each process and arrive at quantitative criteria that should be met to address or mitigate inherent inductive thruster difficulties. The effects of preionization in lowering the discharge energy requirements relative to a case where no preionization is employed, and in influencing the location of the initial current sheet, are described. The relevant performance scaling parameters for the acceleration stage are reviewed, emphasizing their physical importance and the numerical values required for efficient acceleration. The scaling parameters are then related to the design of the pulsed power train providing current to the acceleration stage. The impact of various choices in pulsed power train and circuit topology selection are reviewed, paying special attention to how these choices mitigate or exacerbate switching, lifetime, and power consumption issues.

Polzin, Kurt A.↗
DOE OSTI2023

Enhanced, continuous, liquid-liquid extraction and in-situ separation of volatile fatty acids from fermentation broth

In 2018 alone, the US landfilled 35.3 million tons of food waste, about 24% of the total landfilled mass. In addition to the negative impacts landfills have demonstrated on the environment and human health, some states have begun to outlaw or dissuade the disposal of food waste and sewage sludge into landfills altogether. An urgent need has thus been created for the development of digestion processes like anaerobic digestion (AD) and arrested methanogenesis (AM) to convert food waste into valuable chemical products. Unfortunately, the buildup of volatile fatty acids (VFAs) during these processes eventually halts the reaction, and energy efficient methodologies for VFA removal are critical for the operation of fermenters. Additionally, VFAs themselves can serve as valuable chemical precursors, and recently AD processes have been modified to increase VFA production during fermentation. However, even with significant research over the past three decades, the separation of VFAs from the fermenter broth has remained expensive. Moreover, the separation of these VFAs from the fermenter broth may cost up to 50% of the entire process budget, hindering the widespread commercial adoption of AD and AM. Here we present a novel liquid-liquid extraction process termed CLEANS (Continuous Liquid-liquid Extraction And iN-situ Separation) as a highly efficient method for continuously separating VFAs from a real fermentation broth solely under gravity. Our optimized process (using an aqueous broth feed pH of 2.5, tri-noctylamine as an extractant, and a 10:1 ratio of aqueous broth to organic extractant), achieved a VFA distribution constant K D = 44.5 ± 7.9, a single-pass recovery = 81.3 ± 2.5%, and an extraction factor = 8.1 ± 0.3. These KD values are over an order of magnitude higher than what has been previously reported for comparable processes. A high aqueous-to-organic flowrate ratio, enabled for the first time by CLEANS, was found to be particularly crucial for achieving optimal extraction. Our separation process demonstrates excellent reproducibility and potential for scalability. The economic and environmental implications of this work are briefly discussed.

42 ENGINEERING↗
NASA NTRS1993

Design of a lunar propellant processing facility. NASA/USRA advanced program

Mankind's exploration of space will eventually lead to the establishment of a permanent human presence on the Moon. Essential to the economic viability of such an undertaking will be prudent utilization of indigenous lunar resources. The design of a lunar propellant processing system is presented. The system elements include facilities for ore processing, ice transportation, water splitting, propellant storage, personnel and materials transportation, human habitation, power generation, and communications. The design scenario postulates that ice is present in the lunar polar regions, and that an initial lunar outpost was established. Mining, ore processing, and water transportation operations are located in the polar regions. Water processing and propellant storage facilities are positioned near the equator. A general description of design operations is outlined below. Regolith containing the ice is mined from permanently-shaded polar craters. Water is separated from the ore using a microwave processing technique, and refrozen into projectiles for launch to the equatorial site via railgun. A mass-catching device retrieves the ice. This ice is processed using fractional distillation to remove impurities, and the purified liquid water is fed to an electrolytic cell that splits the water into vaporous hydrogen and oxygen. The hydrogen and oxygen are condensed and stored separately in a tank farm. Electric power for all operations is supplied by SP-100 nuclear reactors. Transportation of materials and personnel is accomplished primarily using chemical rockets. Modular living habitats are used which provide flexibility for the placement and number of personnel. A communications system consisting of lunar surface terminals, a lunar relay satellite, and terrestrial surface stations provides capabilities for continuous Moon-Moon and Moon-Earth transmissions of voice, picture, and data.

Batra, Rajesh↗
NASA NTRS2005

Applying Qualitative Hazard Analysis to Support Quantitative Safety Analysis for Proposed Reduced Wake Separation Conops

This paper describes a scenario-driven hazard analysis process to identify, eliminate, and control safety-related risks. Within this process, we develop selective criteria to determine the applicability of applying engineering modeling to hypothesized hazard scenarios. This provides a basis for evaluating and prioritizing the scenarios as candidates for further quantitative analysis. We have applied this methodology to proposed concepts of operations for reduced wake separation for closely spaced parallel runways. For arrivals, the process identified 43 core hazard scenarios. Of these, we classified 12 as appropriate for further quantitative modeling, 24 that should be mitigated through controls, recommendations, and / or procedures (that is, scenarios not appropriate for quantitative modeling), and 7 that have the lowest priority for further analysis.

Shortle, John F.↗
DOE OSTI2025

Disruptive thermal-spectrum molten salt breeder reactor fuel cycle technologies

Multiple, disruptive fuel salt processing technologies for thermal-spectrum molten salt breeder reactors (TS-MSBRs) have been conceived of and brought to laboratory levels of maturity since the termination of the historic U.S. government program. This paper describes these technologies and the role that they could serve in decreasing the remaining technical risks for TS-MSBR deployment. In conclusion, the focus of the paper is on describing how the technologies could integrate into a dramatically simpler, proliferation resistant fuel salt processing system as well as identifying remaining development hurdles.

11 - NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2022

Parametric Testing and Evaluation of a Novel Biphasic Absorption Process for Post-Combustion Carbon Capture

A novel biphasic CO2 absorption process (BiCAP) is being developed at the University of Illinois. BiCAP is enabled by using a new class of biphasic solvents developed based on multi-property criteria for postcombustion carbon capture. The process was previously demonstrated at the lab-scale, including in 10 kWe absorption and desorption column systems. In the current study, the process has been scaled up by building and testing a 40 kWe integrated capture skid at a power plant. Parametric tests for two biphasic solvents were conducted with the synthetic flue gas made of bottle CO2 gas and air to validate the performance and operational flexibility of the unit with respect to varying process or operating conditions. Operation of the phase separator, which is unique equipment to BiCAP, was verified to be stable and efficient. Two liquid phases could be separated via static settlement based on a density difference and >90% of the CO2 absorbed was concentrated in the separated CO2-rich phase. Results of parametric tests showed that the minimum heat duty appeared at the optimal stripping pressure. A higher stripping temperature was more favourable to improve overall energy performance. Introducing a secondary cold solvent feed stream to the top of the stripper via bypassing the cross heat exchanger helped reduce the heat loss carried with water vapour. Test results also revealed that the heat duty requirement was comparable when the CO2 concentration in flue gas decreased from ~11 to 4 vol.% as the phase separation decoupled the absorption and desorption steps in BiCAP. Under typical steady-state conditions, both biphasic solvents lowered the process heat duty by >40% compared with the reference 30 wt.% monoethanolamine solvent.

Absorption↗
DOE OSTI2023

Metal-oxide cages open up strategy for processing nuclear waste

We report the ability to separate the radioactive element americium from spent nuclear fuel would lower the long-term hazards of nuclear waste. An inorganic molecular cage that selectively binds to americium opens up a separation strategy.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
DOE OSTI2023

Biomass Gasification for Chemicals Production Using Chemical Looping Techniques (Final Report)

The Ohio State University (OSU) is investigating the Biomass to Syngas (BTS) chemical looping technology to produce syngas for chemical production applications from biomass under US Department of Energy (DOE) Award #DE-EE0007530. The BTS process aligns with the programmatic area of interest of “Conversion, via biological, thermal, catalytic or chemical means, of acceptable feedstocks into advanced biofuels and/or biobased products including intermediate and end-use products”. Compared to conventional biomass gasification processes, the BTS process eliminates the need for air separation units and tar reforming reactors, which leads to energy efficiency improvement and capital cost reduction. The overall objective is to ascertain the potential of biomass gasification based on the chemical looping technique through mitigation of the possible techno-economic challenges in the steps of scale up for commercialization. The scope of work consists of 1) designing, constructing and operating a 10 kWth commercially scalable sub-pilot BTS system and; 2) completing a comprehensive techno-economic analysis (TEA) of the BTS process using methanol production as an example. Over the course of the project, the project team completed the design, fabrication, and operation of a 10 kWth sub-pilot scale test unit for the BTS process. Corn cob and wood pellets were successfully tested in the unit for high purity syngas generation in extended test campaigns that totals over 200 hours. Syngas purity (H2 and CO) of >70% was achieved with a CH 4 concentration of <6%. The H 2 /CO ratio was greater than 1.8. A comprehensive techno-economic analysis was performed to compare the BTS process and a reference indirectly heated gasification process for methanol synthesis. The result, updated with experimental results for BTS process performance, shows a methanol required selling price (MSP) of $\$ $1.15/gal, compared to $1.28/gal for the reference case.

08 HYDROGEN↗
NASA NTRS2006

Extension of DAMAS Phased Array Processing for Spatial Coherence Determination (DAMAS-C)

The present study reports a new development of the DAMAS microphone phased array processing methodology that allows the determination and separation of coherent and incoherent noise source distributions. In 2004, a Deconvolution Approach for the Mapping of Acoustic Sources (DAMAS) was developed which decoupled the array design and processing influence from the noise being measured, using a simple and robust algorithm. In 2005, three-dimensional applications of DAMAS were examined. DAMAS has been shown to render an unambiguous quantitative determination of acoustic source position and strength. However, an underlying premise of DAMAS, as well as that of classical array beamforming methodology, is that the noise regions under study are distributions of statistically independent sources. The present development, called DAMAS-C, extends the basic approach to include coherence definition between noise sources. The solutions incorporate cross-beamforming array measurements over the survey region. While the resulting inverse problem can be large and the iteration solution computationally demanding, it solves problems no other technique can approach. DAMAS-C is validated using noise source simulations and is applied to airframe flap noise test results.

Brooks, Thomas F.↗
DOE OSTI2016

Method of separating and de-watering fine particles

A process for cleaning and dewatering hydrophobic particulate materials is presented. The process is performed in two steps: 1) agglomeration of the hydrophobic particles in a first hydrophobic liquid/aqueous mixture; followed by 2) dispersion of the agglomerates in a second hydrophobic liquid to release the water trapped within the agglomerates along with the entrained hydrophilic particles.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗