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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 397 records · Page 22
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

A Techno-economic Analysis for Integrating an Electrochemical Reactor into a Lignocellulosic Biorefinery for Production of Industrial Chemicals and Hydrogen

In this study, we present a techno-economic analysis for integrating an electrochemical reactor into a lignocellulosic biorefinery for the purpose of converting biorefinery lignin to higher-value industrial chemicals with co-generation of hydrogen. We consider how the electrochemical reactor impacts the manufacturing costs for producing biofuel and determine a break-even value for the lignin oxidation product stream, which is the minimum lignin conversion product stream value that renders the cost to produce biofuel the same as in the typical biorefinery concept. We conclude that at low extents of lignin conversion, the break-even product stream value is likely too high for the process to be feasible. However, at higher extents of lignin conversion, the break-even product stream value may be between 1.00 and 2.00/kg, depending on capital cost and other manufacturing costs like depreciation. Here the potential markets for the biomass conversion products include resin manufacturing, where the products would compete with petroleum-derived resin precursors.

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

Large-Scale Hydrogen Storage Cyber Risk Assessment

Hydrogen storage systems may become more widely deployed throughout the country, and so it is possible that individual and interconnected systems will be exposed to cyber-attacks. These events can cause physical and financial harm to employees, people in the vicinity of the facility, and the company that owns the facility. The two main ways bad actors may access information or control from a hydrogen storage facility are through information technology and operations technology devices, the former of which refers to data and information from networked devices and the latter of which refers to onsite controls for the physical system. Both types of entryways into the system should be considered when companies conduct cyber risk assessments and when regulators develop or revise relevant codes and standards. This report analyzes cybersecurity risks associated with a generic hydrogen storage system by outlining the system's purpose and the importance of its cybersecurity. The hydrogen storage system architecture and communication protocols are provided to understand potential cyber vulnerabilities. Later, an event tree analysis is performed on hydrogen operation to identify system weaknesses by outlining potential attack scenarios. This report also identifies critical cyber assets related to different hydrogen operations followed by an examination of potential threats, and the impact of cyber assets on those operational assets.

08 HYDROGEN↗
DOE OSTI2024

Large-Scale Hydrogen Storage Cyber Risk Assessment

Hydrogen storage systems are becoming more widely deployed throughout the country, and as their presence continues to grow, it is possible that individual and interconnected systems will be exposed to cyber-attacks. These events can cause physical and financial harm to employees, people in the vicinity, and to the company that owns the facility. The two main mechanisms malicious actors may access information or control from a hydrogen storage facility are through information technology and operations technology devices, the former of which refers to data and information from networked devices and the latter of which refers to onsite controls for the physical system. Both types of entryways into the system should be considered when facility managers conduct cyber risk assessments and when regulators develop or revise relevant codes and standards. This report analyzes cybersecurity risks applicable to a wide variety of hydrogen storage systems by outlining the system's purpose and the importance of its cybersecurity. The hydrogen storage system architecture and communication protocols are provided to understand potential cyber vulnerabilities. Later, an event tree analysis is performed on hydrogen operation to identify system weaknesses by outlining potential attack scenarios. This report also identifies critical cyber assets related to different hydrogen operations followed by an examination of potential threats, and the impact of cyber assets on those operational assets.

08 HYDROGEN↗
DOE OSTI2021

Nickel(ii) complexes based on dithiolate–polyamine binary ligand systems: crystal structures, hirshfeld surface analysis, theoretical study, and catalytic activity study on photocatalytic hydrogen generation

To ascertain the influence of binary ligand systems [1,1-dicyanoethylene-2,2-dithiolate (i-mnt -2 ) and polyamine {tetraen = tris(2-aminoethyl)amine, tren = diethylene triamine and opda = o-phenylenediamine}] on the coordination modes of the Ni(II) metal center and resulting supramolecular architectures, a series of nickel(II) thiolate complexes [Ni(tetraen)(i-mnt)](DMSO) (1), [Ni 2 (tren) 2 (i-mnt) 2 ] (2), and [Ni 2 (i-mnt) 2 (opda) 2 ] n (3) have been synthesized in high yield in one step in water and structurally characterized by single crystal X-ray crystallography and spectroscopic techniques. X-ray diffraction studies disclose the diverse i-mnt -2 coordination to the Ni +2 center in the presence of active polyamine ligands, forming a slightly distorted octahedral geometry (NiN 4 S 2 ) in 1, square planar (NiS 4 ) and distorted octahedral geometries (NiN 6 ) in the bimetallic co-crystallized aggregate of cationic [Ni(tren) 2 ] +2 and anionic [Ni(i-mnt) 2 ] -2 in 2, and a one dimensional (1D) polymeric chain along the [100] axis in 3, having consecutive square planar (NiS 4 ) and octahedral (NiN 6 ) coordination kernels. The N–H···O, N–H···S, N–H···N, N–H···S, N–H···N, and N–H···O type hydrogen bonds stabilize the supramolecular assemblies in 1, 2, and 3 respectively imparting interesting graph-set-motifs. The molecular Hirshfeld surface analyses (HS) and 2D fingerprint plots were utilized for decoding all types of non-covalent contacts in the crystal networks. Atomic HS analysis of the Ni +2 centers reveals significant Ni–N metal–ligand interactions compared to Ni–S interactions. We have also studied the unorthodox interactions observed in the solid state structures of 1–3 by QTAIM and NBO analyses. Moreover, all the complexes proved to be highly active water reduction co-catalysts (WRC) in a photo-catalytic hydrogen evolution process involving iridium photosensitizers, wherein 2 and 3 having a square planar arrangement around the nickel center(s) – were found to be the most active ones, achieving 1000 and 1119 turnover numbers (TON), respectively.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

Methane Catalytic Pyrolysis by Microwave and Thermal Heating over Carbon Nanotube-Supported Catalysts: Productivity, Kinetics, and Energy Efficiency

Methane catalytic pyrolysis, which is the reaction to produce hydrogen and carbon without emitting CO 2 , represents an approach for decarbonization using natural gas as an energy resource. In this work, the endothermic pyrolysis reaction was carried out under two heating scenarios: convective thermal heating and microwave-driven irradiative heating. The pyrolysis reaction was conducted at 550-600 °C over carbon nanotube-supported Ni-Pd and Ni-Cu catalysts. On both catalysts, an enhanced methane conversion rate was observed under microwave irradiation. The enhanced catalytic activity was hypothetically caused by the presence of free electrons in the carbon atoms within CNT that enabled the CNT support to absorb microwave energy effectively and to be heated efficiently by microwave. The microwave catalytic pyrolysis has shown improvement in kinetics, where the apparent activation energy dropped from 45.5 kJ/mol under conventional convective heating to 24.8 kJ/mol under microwave irradiation. When the methane conversion rate is increased by 37 %, the microwave power consumption only changed by 10.8 %. The research demonstrated the potential of transforming natural gas to clean hydrogen and value-added carbon in a more energy-efficient way. Process simulation and techno-economic analysis showed that potentially hydrogen minimum selling price of about $1 /kg H 2 could be achieved.

03 NATURAL GAS↗
DOE OSTI2021

Collaborative Research: Large Scale Intensity Mapping of Neutral Hydrogen with the Tianlai Pathfinders

This program developed new analysis methods for current and upcoming cosmological hydrogen 21cm intensity mapping data from the Tianlai experiment, located in a radio quiet area of Western China. Such mapping provides important clues to the evolution of gas and galaxies in the early universe. The experiment measured the three-dimensional large-scale structure of the universe via hydrogen emission from distant galaxies. The primary goal was to develop ways to handle the large foreground signal, which has been previously quantified in a pathfinder 21cm program conducted on NSF's Green Bank Telescope.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2022

Controlling Catalyst–Semiconductor Contacts: Interfacial Charge Separation in p-InP Photocathodes

Charge-carrier-selective interfaces between electrocatalyst particles and semiconductor light absorbers are critical for solar photochemistry but controlling their properties is challenging. Using thin films and nanoparticle arrays of Pt hydrogen-evolution catalysts on p-InP (a high-performance photocathode material), along with macroscopic and nanoscopic electrical and chemical analysis, we show how hydrogen alloying, the pinch-off effect for nanoscale contacts, and the formation of a native surface oxides all play different roles in creating charge-carrier-selective junctions. As a result, the new insights can be broadly applied to photocathodes, photoanodes, and overall water-splitting systems to control charge-carrier selectivity and improve performance.

14 SOLAR ENERGY↗
NASA NTRS1992

The constitution of the atmospheric layers and the extreme ultraviolet spectrum of hot hydrogen-rich white dwarfs

An analysis is presented of the atmospheric properties of hot, H-rich, DA white dwarfs that is based on optical, UV, and X-ray observations aimed at predicting detailed spectral properties of these stars in the range 80-800 A. The divergences between observations from a sample of 15 hot DA white dwarfs emitting in the EUV/soft X-ray range and pure H synthetic spectra calculated from a grid of model atmospheres characterized by Teff and g are examined. Seven out of 15 DA stars are found to consistently exhibit pure hydrogen atmospheres, the remaining seven stars showing inconsistency between FUV and EUV/soft X-ray data that can be explained by the presence of trace EUV/soft X-ray absorbers. Synthetic data are computed assuming two other possible chemical structures: photospheric traces of radiatively levitated heavy elements and a stratified hydrogen/helium distribution. Predictions about forthcoming medium-resolution observations of the EUV spectrum of selected hot H-rich white dwarfs are made.

Vennes, Stephane↗
DOE OSTI2022

Asymmetrical C–C Coupling for Electroreduction of CO on Bimetallic Cu–Pd Catalysts

Electroreduction of carbon monoxide (CO) possesses great potential for achieving the renewable synthesis of hydrocarbon chemicals from CO 2 . We report here selective reduction of CO to acetate using Cu–Pd bimetallic electrocatalysts. High activity and selectivity are demonstrated for CO-to-acetate conversion with >200 mA/cm 2 in geometric current density and >65% in Faradaic efficiency (FE). An asymmetrical C–C coupling mechanism is proposed to explain the composition-dependent catalytic performance and high selectivity toward acetate. This mechanism is supported by the computationally predicted shift of the *CO adsorption from the top-site configuration on Cu (or Cu-rich) surfaces to the bridge sites of Cu–Pd bimetallic surfaces, which is also associated with the reduction of the CO hydrogenation barrier. Further kinetic analysis of the reaction order with respect to CO and Tafel slope supports a reaction pathway with *CO–*CHO recombination following a CO hydrogenation step, which could account for the electroreduction of CO to acetate on the Cu–Pd bimetallic catalysts. Furthermore, our work highlights how heteroatomic alloy surfaces can be tailored to enable distinct reaction pathways and achieve advanced catalytic performance beyond monometallic catalysts.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS1992

Special tests and destructive physical analyses as used by the Aerospace Corporation with nickel-hydrogen cells

The destructive physical analysis (DPA) of electrochemical devices is an important part of the overall test. Specific tests were developed to investigate the degradation mode or the failure mechanism that surfaces during the course of a cell being assembled, acceptance tested, and life-cycle tested. The tests that have been developed are peculiar to the cell chemistry under investigation. Tests are often developed by an individual or group of researchers as a result of their particular interest in an unresolved failure mechanism or degradation mode. A series of production, operational, and storage issues that were addressed by the Electrochemistry Group at The Aerospace Corporation are addressed. As a result of these investigations, as well as associated research studies carried out to develop a clearer understanding of the nickel oxyhydroxide electrode, a series of unique and useful specialized tests were developed. Some of these special tests were assembled to describe the methods that were found to be particularly useful in resolving a wide spectrum of manufacturing, operational, and storage issues related to nickel-hydrogen cells. The general methodology of these tests is given here with references listed to provide the reader with a more detailed understanding of the tests. The tests are classified according to the sequencing, starting with the impregnation of the nickel plaque material and culminating with the storage of completed cells. The details of the wet chemical procedures that were found to be useful because of their accuracy and reproducibility are given. The equations used to make the appropriate calculations are listed.

Zimmerman, A. H.↗
DOE OSTI2022

The development of natural gas and hydrogen pipeline capital cost estimating equations

Natural gas pipeline cost data collected by the Oil and Gas Journal (O&GJ) for interstate pipelines constructed from 1980 through 2017 were used to develop capital cost estimating equations that are a function of pipeline diameter, length, and U.S. region. Equations were developed for material, labor, miscellaneous, and right-of-way costs, the four cost components in the O&GJ data, for six different regions of the United States (U.S.). Each equation is a function of pipeline diameter and length. Adjustment mechanisms were then developed for converting the natural gas pipeline equations into equations for estimating the costs of hydrogen pipelines. These adjustments were based in part on an analysis completed by the National Institute for Standards and Technology (NIST). Here the results of this work were used to update cost models in the Hydrogen Delivery Scenario Analysis Model (HDSAM), developed by Argonne National Laboratory for the U.S. Department of Energy’s Hydrogen Program. Our analysis shows a wide range of pipeline cost across different U.S. regions, especially with respect to labor and right-of-way costs. The developed cost formulas for hydrogen pipelines are both important and timely as hydrogen is being considered as a zero-carbon energy carrier with the potential to decarbonize all energy sectors, and the cost of hydrogen transportation is essential for techno-economic analysis of its potential use in these sectors.

03 NATURAL GAS↗