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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 811 records · Page 45

Computation of conventional and alternative jet fuel sensitivity to lean blowout

Large Eddy Simulations (LES) are performed to compute the sensitivity of a conventional (A-2) and an alternate bio-jet (C-1) fuel to Lean Blowout (LBO). A realistic aviation gas turbine engine combustor configuration is considered. Reliable experimental LBO data and OH* chemiluminescence data for the conventional and alternate jet fuel in the combustor configuration have recently become available. The present work utilizes a highly automated, on-the-fly meshing strategy, along with adaptive mesh refinement, to demonstrate the feasibility of capturing the realistic combustion processes. A Lagrangian framework, with initial conditions specified using measurements of spray statistics, is used to model the fuel spray. Newly developed compact reaction mechanisms based on fuel surrogates are validated for the A-2 and the C-1 fuels. The compact reaction mechanisms are implemented using a detailed finite rate chemistry solver. Spray statistics computed by the present LES simulations compare well with available measurements at stable flame conditions near the lean blowout limit. The computed shape of the stable flame as represented by line integrated OH concentrations compares well with the experimental OH* chemiluminescence data. Lean blowout is reached by gradually decreasing the fuel flow rate in the computations, similar to that in the experiments. The results of the LES simulations effectively capture the fuel composition effects and estimate the sensitivity of the LBO limits to the fuel type. The computed trends in LBO limits agree within engineering accuracy with the experimental results for conventional and alternative aviation fuels. The methodology for predicting the fuel composition effects on the lean blowout limits in a fully resolved realistic, complex combustor is established for the first time.

Adaptive mesh refinement↗

Neutron radiography of irradiated nuclear fuel at Idaho National Laboratory

Neutron radiography of irradiated nuclear fuel provides more comprehensive information about the internal condition of irradiated nuclear fuel than any other non-destructive technique to date. Idaho National Laboratory (INL) has multiple nuclear fuels research and development programs that routinely evaluate irradiated fuels using neutron radiography. The Neutron Radiography reactor (NRAD) sits beneath a shielded hot cell facility where neutron radiography and other evaluation techniques are performed on these highly radioactive objects. The NRAD currently uses the foil-film transfer technique for imaging fuel that is time consuming but provides high spatial resolution. This study describes the NRAD and hot cell facilities, the current neutron radiography capabilities available at INL, planned upgrades to the neutron imaging systems, and new facilities being brought online at INL related to neutron imaging.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Chemical Transformations of Poplar Lignin during Cosolvent Enhanced Lignocellulosic Fractionation Process

Converting lignocellulosic biomass to biofuels and bioproducts is significantly hindered by the innate recalcitrance of biomass to chemical and biological breakdown, and it usually requires a pretreatment stage in order to improve conversion yields. A promising novel pretreatment named Cosolvent Enhanced Lignocellulosic Fractionation (CELF) involving dilute acid treatment of biomass in a THF–water mixture was recently developed to overcome biomass recalcitrance. Detailed elucidation of physicochemical structures of the fractionated lignin that is precipitated from CELF pretreatment of hardwood poplar, also called CELF lignin, reveals transformations in its molecular weights, monolignol composition, and hydroxyl group content. Isolated CELF lignin revealed dramatic reductions in its molecular weight by up to ~90% compared with untreated native lignin. Furthermore, CELF lignin’s β-O-4 interunit linkages were extensively cleaved after CELF pretreatment as indicated by a semiquantitative HSQC NMR analysis. This is further evidenced by a 31P NMR analysis showing a significant decrease in aliphatic OH groups due to the oxidation of lignin side chains, whereas the content of total phenolic OH groups in CELF lignin significantly increased due to cleavage of interunit linkages. In conclusion, the CELF process generated a uniquely tunable and highly pure lignin feedstock of low content aryl ether linkages, low molecular weight, and high amount of phenolic hydroxyl groups, suitable for its development into fuels, chemicals, and materials.

09 BIOMASS FUELS↗

In Situ X-ray Absorption Spectroscopy of a Synergistic Co–Mn Oxide Catalyst for the Oxygen Reduction Reaction

Identifying the catalytically active site(s) in the oxygen reduction reaction (ORR), under real-time electrochemical conditions, is critical to the development of fuel cells and other technologies. We have employed in situ synchrotron-based X-ray absorption spectroscopy (XAS) to explore the synergistic interaction of a Co–Mn oxide catalyst which exhibits impressive ORR activity in alkaline fuel cells. X-ray absorption near edge structure (XANES) was used to track the dynamic structural changes of Co and Mn under both steady state (constant applied potential) and nonsteady state (potentiodynamic cyclic voltammetry, CV). Under steady state conditions, both Mn and Co valences decreased at lower potentials, suggesting the conversion from Mn-(III,IV) and Co(III) to Mn(II,III) and Co(II), respec-tively. Rapid X-ray data acquisition, combined with a slow sweep rate in CV, enabled a 3 mV resolution in the applied potential, approaching a nonsteady (potentiody-namic) state. Changes in the Co and Mn valence states were simultaneous and exhibited periodic patterns that tracked the cyclic potential sweeps. To the best of our knowledge, this represents the first study, using in situ XAS, to resolve the synergistic catalytic mechanism of a bimetallic oxide. Strategies developed/described herein can offer an enticing approach to unveil the reaction mechanism for other multimetallic electrocatalysts.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

O 2 Activation by a Heterobimetallic Zr/Co Complex

Oxygen reduction is a critical half reaction in renewable fuel cell development and a key step in the development of aerobic oxidation reactions. We report rapid two-electron O 2 reduction by a d 0 Zr IV center with an appended redox-active Co –I site serving as an electron reservoir. The early/late heterobimetallic Zr/Co complex (THF)Zr(MesNP i Pr 2 ) 3 CoCN t Bu (1) reacts readily with O 2 and O atom transfer reagents to generate reactive oxygenated species including terminal peroxo and oxo complexes, (O 2 )Zr(MesNP i Pr 2 ) 3 CoCN t Bu (2) and O≡Zr(MesNP i Pr 2 ) 3 CoCN t Bu (3). The bimetallic Zr/Co complex provides a new cooperative synthetic pathway to promote multielectron redox processes such as oxygen reduction, with each metal playing a distinct role as a substrate binding site or redox mediator.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Unveiling new stable manganese based photoanode materials via theoretical high-throughput screening and experiments

Here, with the increasing energy demand, developing renewable fuel production strategies such as photoelectrocatalytic hydrogen production is critical to mitigating the global climate change. In this work, we experimentally validate a new stable and photoactive material, Mg 2 MnO 4 , from the exhaustive theoretical exploration of the chemical space of X (=Mg and Ca), Mn and O.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Enhanced and stabilized hydrogen production from methanol by ultrasmall Ni nanoclusters immobilized on defect-rich h-BN nanosheets

Employing liquid organic hydrogen carriers (LOHCs) to transport hydrogen to where it can be utilized relies on methods of efficient chemical dehydrogenation to access this fuel. Therefore, developing effective strategies to optimize the catalytic performance of cheap transition metal-based catalysts in terms of activity and stability for dehydrogenation of LOHCs is a critical challenge. Here, we report the design and synthesis of ultrasmall nickel nanoclusters (∼1.5 nm) deposited on defect-rich boron nitride (BN) nanosheet (Ni/BN) catalysts with higher methanol dehydrogenation activity and selectivity, and greater stability than that of some other transition-metal based catalysts. The interface of the two-dimensional (2D) BN with the metal nanoparticles plays a strong role both in guiding the nucleation and growth of the catalytically active ultrasmall Ni nanoclusters, and further in stabilizing these nanoscale Ni catalysts against poisoning by interactions with the BN substrate. We provide detailed spectroscopy characterizations and density functional theory (DFT) calculations to reveal the origin of the high productivity, high selectivity, and high durability exhibited with the Ni/BN nanocatalyst and elucidate its correlation with nanocluster size and support–nanocluster interactions. This study provides insight into the role that the support material can have both regarding the size control of nanoclusters through immobilization during the nanocluster formation and also during the active catalytic process; this twofold set of insights is significant in advancing the understanding the bottom-up design of high-performance, durable catalytic systems for various catalysis needs.

08 HYDROGEN↗

Purification of U from U-10Mo scrap generated during the fabrication of high performance research reactor fuel

A low enriched U-Mo alloy fuel is under development to replace highly enriched U fuels currently used in United States high performance research reactors. The alloy casting and fuel fabrication processes will generate scrap streams containing low enriched U (LEU) which must be recovered. Solvent extraction processes were designed using the Argonne Model for Universal Solvent Extraction (AMUSE) to purify solutions containing 20 and 50 g/L U. The feed for the solvent extraction processes was prepared from solutions generated from the dissolution of U-10Mo-Zr foils and U-10Mo-Zr-Al mini-plates. The U purification processes were demonstrated using two, 16-stage banks of miniature mixer-settlers. The solvent extraction experiments demonstrated that all design objectives for the U purification processes could be met. The U recovery in the product stream for each flowsheet was ≥99.9%. The flowsheet demonstrations also showed that the purity of the U Product will meet the requirements of the ASTM International C1462-21 specification for LEU metal enriched to less than 20% 235 U. In conclusion, the AMUSE modeling for both flowsheet demonstrations was validated by comparing predicted and measured concentrations of U, Mo, and Zr in the exit streams and stage samples at steady-state conditions in the mixer-settlers.

modified PUREX process↗

Enabling the democratization of the genomics revolution with a fully integrated web-based bioinformatics platform

Continued advancements in sequencing technologies have fueled the development of new sequencing applications and promise to flood current databases with raw data. A number of factors prevent the seamless and easy use of these data, including the breadth of project goals, the wide array of tools that individually perform fractions of any given analysis, the large number of associated software/hardware dependencies, and the detailed expertise required to perform these analyses. To address these issues, we have developed an intuitive web-based environment with a wide assortment of integrated and cutting-edge bioinformatics tools in pre-configured workflows. These workflows, coupled with the ease of use of the environment, provide even novice next-generation sequencing users with the ability to perform many complex analyses with only a few mouse clicks and, within the context of the same environment, to visualize and further interrogate their results. As a result, this bioinformatics platform is an initial attempt at Empowering the Development of Genomics Expertise (EDGE) in a wide range of applications for microbial research.

59 BASIC BIOLOGICAL SCIENCES↗

Thermonuclear Power Engineering: 60 Years of Research. What Comes Next?

This paper summarizes results of more than half a century of research of high-temperature plasmas heated to a temperature of more than 100 million degrees (10{sup 4} eV) and magnetically insulated from the walls. The energy of light-element fusion сan be used for electric power generation or as a source of fissionable fuel production (development of a fusion neutron source—FNS). The main results of studies of tokamak plasmas which were obtained in the Soviet Union with the greatest degree of thermal plasma isolation among all other types of devices are presented. As a result, research programs of other countries were redirected to tokamaks. Later, on the basis of the analysis of numerous experiments, the international fusion community gradually came to an opinion that it is possible to build a tokamak (ITER) with Q > 1 (where Q is the ratio of the fusion power to the external power injected into the plasma). The ITER program objective is to achieve Q = 1–10 for a discharge time of up to 1000 s. The implementation of this goal does not solve the problem of a steadystate operation. The solution to this problem is a reliable first wall and current generation. This is a task of the next fusion power plant construction stage, called DEMO. Comparison of DEMO and FNS parameters shows that, at this development stage, the operating parameters and conditions of these devices are identical.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

Research and Development for Off-Road Fuel Cell Applications U.S. Department of Energy Grant DE-FG36-04GO14303 - Final Report

Off-road concerns are related to the effects of shock and vibration and air quality on fuel cell power requirements. Mechanical stresses on differing material makeup and mass distribution within the system may render some components susceptible to impulse trauma while others may show adverse effects from harmonic disturbances or broad band mechanical agitation. One of the recognized challenges in fuel cell systems air purification is in providing a highly efficient particulate and chemical filter with minimal pressure drop. PEM integrators do not want additional parasitic loads added to the system as compensation for a highly efficient yet highly restrictive filter. Additionally, there is challenge in integrating multiple functions into a single air intake module tasked with effectively filtering high dust loads, diesel soot, pesticides, ammonias, and other anticipated off-road contaminants. This project has investigated both off-road associated issues cumulating in the prototype build and testing of two light duty off-road vehicles with integrated fuel cell power plant systems.

08 HYDROGEN↗

Fuel Cell Technical Team Roadmap

The Fuel Cell Technical Team promotes the development of a fuel cell power system for an automotive powertrain that meets the U.S. DRIVE Partnership (United States Driving Research and Innovation for Vehicle efficiency and Energy sustainability) goals.

fuel cell system↗

Final Report: Hydrogen Production Pathways Cost Analysis (2013 – 2016)

This report summarizes work conducted under a three year Department of Energy (DOE) funded project to Strategic Analysis, Inc. (SA) to analyze multiple hydrogen (H 2 ) production technologies and project their corresponding levelized production cost of H 2 . The analysis was conducted using the H2A Hydrogen Analysis Tool developed by the DOE and National Renewable Energy Laboratory (NREL). The project was led by SA but conducted in close collaboration with the NREL and Argonne National Laboratory (ANL). In-depth techno-economic analysis (TEA) of five different H 2 production methods was conducted. These TEAs developed projections for capital costs, fuel/feedstock usage, energy usage, indirect capital costs, land usage, labor requirements, and other parameters, for each H 2 production pathway, and use the resulting cost and system parameters as inputs into the H2A discounted cash flow model to project the production cost of H 2 ($/kgH 2 ). Five technologies were analyzed as part of the project and are summarized in this report: Proton Exchange Membrane technology (PEM), High temperature solid oxide electrolysis cell technology (SOEC), Dark fermentation of biomass for H 2 production, H 2 production via Monolithic Piston-Type Reactors with rapid swing reforming and regeneration reactions, and Reformer-Electrolyzer-Purifier (REP) technology developed by Fuel Cell Energy, Inc. (FCE).

08 HYDROGEN↗

Ceramic Coatings for Clad (The C 3 Project): Advanced Accident-Tolerant Ceramic Coatings for Zr-Alloy Cladding

The goal of this NEUP-IRP project is to develop a fuel concept based on an advanced ceramic coating for Zr-alloy cladding. The coated cladding must exhibit demonstrably improved performance compared to conventional Zr-alloy clad in the following respects: During normal service, the ceramic coating should decrease cladding oxidation and hydrogen pickup (the latter leads to hydriding and embrittlement). During a reactor transient (e.g., a loss of coolant accident), the ceramic coating must minimize or at least significantly delay oxidation of the Zr-alloy cladding, thus reducing the amount of hydrogen generated and the oxygen ingress into the cladding. The specific objectives of this project are as follows: To produce durable ceramic coatings on Zr-alloy clad using two possible routes: (i) MAX phase ceramic coatings or similar nitride or carbide coatings; and (ii) graded interface architecture (multilayer) ceramic coatings, using, for instance, an oxide such as yttria-stabilized zirconia (YSZ) as the outer protective layer. To characterize the structural and physical properties of the coated clad samples produced in 1. above, especially the corrosion properties under simulated normal and transient reactor operating conditions. To perform computational analyses to assess the effects of such coatings on fuel performance and reactor neutronics, and to perform fuel cycle analyses to assess the economic viability of modifying conventional Zr-alloy cladding with ceramic coatings. This project meets a number of the goals outlined in the NEUP-IRP call for proposals, including: Improve the fuel/cladding system through innovative designs (e.g. coatings/liners for zirconium-based cladding) Reduce or eliminate hydrogen generation Increase resistance to bulk steam oxidation Achievement of our goals and objectives, as defined above, will lead to safer light-water reactor (LWR) nuclear fuel assemblies, due to improved cladding properties and built-in accident resistance, as well as the possibilities for enhanced fuel/clad system performance and longevity.

36 MATERIALS SCIENCE↗

Research Needs for Uranium-Zirconium- Based Metallic Fuels

The purpose of this report is to summarize the needs and present recommendations related to the future direction for U-Zr-based metallic fuel research (including binary U-Zr and ternary U-Pu-Zr alloys). These needs and recommendations were determined by subject matter experts from various institutions during a two-day workshop held at the University of Florida in November, 2019. During open-floor discussions, the highest priority gaps in our understanding of U-Zr-based fuels were down-selected, and near- and long-term needs that directly impact the implementation of these metallic fuels were identified. The identified near-term needs include investigation of the following phenomena: i) swelling and fission gas release, ii) fuel-cladding chemical interaction, iii) phase evolution/constituent redistribution, and iv) thermal properties of the fuels. The long-term needs are: i) investigation of fuel creep and plasticity and ii) fission product (lanthanide) transport. In addition, there was general agreement that all institutions and subject matter experts would benefit from an open-source metallic fuels database with thermophysical property and microstructural data, along with fuel operation/irradiation history, which should be regularly updated with vetted information from new experimental and computational investigations and used to advance metallic fuels research and development. Finally, we recommend that metallic fuel research should be ongoing and that fuel qualification and fuel optimization should be equally prioritized; research combining experiments with modeling and simulation has the largest potential impact.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Adhesion of Titanium Coatings on Additively Manufactured Stainless Steel [Slides]

Additive manufacturing can improve fuel cell development by increasing design development speed, enabling complex designs through more flexible fabrication, and reducing wasted excess material. The goal of the project is to develop a process for strongly adhering a coating of titanium to additively manufactured stainless steel.

36 MATERIALS SCIENCE↗