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At least 379 records · Page 21

Thermal Extraction and Delivery from Advanced Reactor Systems

This document presents preliminary thermodynamic analysis of thermal extraction and delivery from advanced nuclear reactors. Light-water, high temperature gas, sodium fast, and molten salt reactors are templated and analyzed for thermal extraction from nominal steam production conditions. Uncontrolled, controlled, and partial admission steam extraction methods are described and analyzed to show the differences in system impact from the various methods. Thermal delivery modeling results show comparisons that have become possible through the computational capabilities of the thermal delivery model. Due to the significant degrees of freedom of the problem, specific cases are used to compare the thermodynamic costs of heat transport using various heat transfer fluids. All this work is done using Modelica models, allowing for the future application of models in dynamic analyses beyond the steady-state calculations presented in this report. Appendices describe additional capabilities and methods that can help users analyze complex problems using HYBRID models developed in Modelica.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

SPC-71145 Rev 0 MARVEL Process Heat Extraction System Conceptual Design

The Microreactor Applications Research Validation and Evaluation (MARVEL) reactor will offer experimental capabilities that are not currently available at DOE’s national laboratories. The MARVEL reactor is a microreactor which uses eutectic sodium-potassium alloy (NaK) as a primary coolant. The primary coolant is circulated through four primary loops by natural convection of the coolant. In each loop is a closed well which will accommodate an intermediate heat exchanger (IHX) for extracting heat from the loop. These wells will be referred to in this specification as the “IHX wells”. It is intended for the IHX containment to also be filled with NaK. The MARVEL design team is currently looking for alternative means of extracting heat from these wells to be utilized in downstream applications. This Heat Utilization System (HUS) will enable MARVEL operations including the ability to test, demonstrate, and address issues related to installation, startup, and operations. In addition, it will allow down-stream utilization of process heat for various uses. Depending on the methodology used, the interface between the secondary coolant and the HUS is the Process Heat Extraction System (PHES) and is the subject of this specification.

21 - SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLAN↗

Extraction of Pure Plastic Resins From PCR Plastic Waste by Solvent-Targeted Recovery and Precipitation (STRAP)

For this work, we have been developing a solvent‐based plastic recycling technology called STRAP. The technology is based on dissolving a targeted plastic resin in a specific solvent that does not dissolve other resins. We have demonstrated STRAP in thousands of bench scale experiments for a large variety of wastes. Recently we have demonstrated the technology for PCR, using mixed plastic wastes (MPWs), from a wet Material Recovery Facility (MRF). The process includes (1) infrared (IR) characterization to determine the plastic composition for accurate selection of the solvent to be used for the extraction of the pure resins. (2) Shredding to the right size and aspect ratio required for flowable and fast dissolvable process. (3) Mixing the MPW in the first solvent to dissolve the first resin. (4) Filtration of the solution plastic blend, to separate the nondissolved plastic from the solution. (5) Further filtration of the solution to remove micron‐sized particle of pigments and fibers. (6) Cooling for precipitation. (7) Filtration of pure resins. (8) Drying of a pure resin. (9) Extrusion of the resin to pellets. (10) Generating films or other products from the pure resin. Steps 1–10 can be considered as one‐cycle that extracted the first resin. (11) A second resin can be extracted with a respective solvent from the plastic that did not dissolve in the first cycle and following steps 1–10 described above. The process also includes characterization of interim and final products. The effort includes building a pilot system at 25 kg/h throughput. We will present specific results for various PCR.

IR characterization↗

Quinoa protein extract: an effective alternative for the fining of wine phenolics

Abstract BACKGROUND Lately, there has been an increasing interest in using plant‐derived proteins for wine phenolic fining. Proteins extracted from cereals, potatoes, and legumes have been proposed as effective fining agents, but only those from pea, wheat, and potatoes have been approved for their use in wine. This work aimed at determining the fining ability of quinoa ( Chenopodium quinoa Willd.) protein extracts (QP), compared to commercial fining agents, on red wines. RESULTS The trials compared the performance of QP (30 and 50 g/hL), two potato protein extracts and gelatin, at two different contact times (48 and 96 h), using Petit Verdot, Malbec, and Cabernet Sauvignon wines. Turbidity, total phenolics, precipitable tannins, catechins, and color characteristics were determined. QP reduced the turbidity of all wines in a similar way to commercial fining agents. Both doses of QP significantly reduced tannins and other phenolic measures, including color intensity reductions, in a similar way to commercial fining agents. CONCLUSION QP behaved as an effective fining agent that deserves further studies in order to improve its performance and advance its characterization. © 2022 Society of Chemical Industry.

Pino‐Ramos, Liudis L.↗

Mesophase pitch-based high performance carbon fiber production using coal extracts from mild direct coal liquefaction

Mild direct coal liquefaction (autogenous pressure, no catalyst, no H2 gas) of Springfield coal in fluid catalytic cracking decant oil is shown to effectively produce coal extract precursors to spinnable mesophase pitch. Here this work demonstrates that the coal extract can be thermally treated to obtain mesophase pitch in a facile one-step process, bypassing the production of an intermediate isotropic pitch. Furthermore, the presence of 25 wt.% coal in the initial slurry can increase the yield to mesophase pitch nearly twofold and yield to carbon fiber by approximately 70%. The coal extract-derived mesophase pitch was melt-spun and heat treated to produce carbon fiber with graphitic texture, high modulus (>400 GPa) and tensile strength up to 943 MPa. Overall, this work demonstrates that coal can be effectively utilized to markedly amplify the mesophase pitch and carbon fiber yield from fluid catalytic cracking decant oil by relatively simple processing, while conserving utility as a precursor to high performance carbon fiber and potentially other high value graphitic products.

36 MATERIALS SCIENCE↗

Intensified reactive extraction for the acid-catalyzed conversion of fructose to 5-hydroxymethyl furfural

Here we conduct an experimental study of fructose dehydration to 5-hydroxymethyl furfural (HMF) in a biphasic microreactor as a function of residence time, temperature, and sugar loading using methyl butyl iso-ketone (MIBK) and 2-pentanol as extracting solvents. We demonstrate stable operation with maximum HMF yields of 93% and 87% in the two solvents, respectively, at 200 °C and a residence time of 2 s for a 5 wt% fructose aqueous feed. We report the highest optimal HMF space–time yield of 60 kg/L-hr at 200 °C (10 – 2,500-fold higher than published reports). Unexpectedly, an optimum organic-to-water ratio exists that depends on the solvent. Notably, we observe experimentally an increased fructose rate and HMF yield well above the extraction thermodynamic limit and hypothesize that the solvent plays a dual role, that of an extractant to protect HMF from degradation and a modifier of the fundamental chemistry. We expose mass transfer limitations of microreactors at longer residence times and higher temperatures and provide reactivity maps for their design. We show that batch reactors are unfit for high throughput and distributed manufacturing where small, farm-based systems are necessary.

42 ENGINEERING↗

Repeated freeze-thaw cycles increase extractable, but not total, carbon and nitrogen in a Maine coniferous soil

Northeastern North America has been experiencing warmer winters with reduced snow accumulation, with more frequent winter freeze-thaw cycles. We conducted a laboratory experiment to investigate how increased frequency of freeze-thaw cycles (FTC) would alter soil C and N availability. Organic (O) and mineral (B) horizon soils were collected from a coniferous forest in Maine, processed to exclude roots, and then frozen in the laboratory (-10 °C) with one (FTC-1), two (FTC-2), or six (FTC-6) thaw periods. Soils were analyzed for extractable inorganic ammonium (NH4-N), water extractable organic carbon (WEOC), carbon dioxide flux (respiration), and total C and N. Extractable NH4-N increased following FTC, for both horizons. WEOC in O horizons had a lower SUVA254, indicating a stronger microbial influence (i.e., microbial cell lysis) in these soils after FTC. Respiration in O horizon soils decreased post-incubation and did not differ between FTC and Control soils. In the B horizon, however, FTC soils showed greater respiration than Control soils, suggesting that the newly available nutrients may have stimulated microbial activity. In contrast to these results, total C and N remained unaltered by FTC, presumably because the FTC disturbances represented mostly a translocation of C and N from one pool into another, and losses due to respiration were too small to significantly influence the large TC and TN pools. The effect of FTC on NH4-N did not change with FTC frequency, suggesting that a single FTC is sufficient to alter both C and N availability and quality, and that additional FTC may not have a significant further effect. This study provides fresh insights on how organic and mineral soils might respond to increased freeze-thaw frequency in winter.

Patel, Kaizad F.↗

Parameter extraction approaches for compact modeling of thermoelectric modules

Thermoelectric (TE) cooling has experienced rapid advancements with the foundational understanding of TE materials. TE modules, compact and lightweight devices, have become the prevalent approach for implementing TE technologies. Accurately quantifying TE physical parameters (Seebeck coefficient α, thermal conductivity κ, and thermal resistance ρ) is challenging due to the dynamic temperature changes in operation. Furthermore, extracting lumped property parameters is crucial for designing energy systems using TE modules. Existing research has several limitations, such as lack of comparative analysis between prevalent formulae, reliance on potentially inaccurate vendor-supplied data, disregard for fundamental assumptions, and absence of empirical measurements. Further, this study addresses these gaps by conducting TE material characterization, comparing three existing formulae using vendor datasheets, designing a laboratory test facility for model validation and refinement, and outlining a structured data extraction procedure. The study's novelty lies in multiple key contributions: (1) a detailed comparative analysis of existing formulae for extracting TE property parameter; (2) executing experimental work in a laboratory setting to validate the model and elucidate its limitations; (3) highlighting potential risks; (4) clarifying possible assumptions from both material and engineering perspectives; and (5) considering temperature differential impacts. This comprehensive approach addresses the current research gaps and provides valuable insights into the design and application of TE modules in various energy systems.

36 MATERIALS SCIENCE↗

Post-hazard condition assessment of nuclear piping-equipment systems: Novel approach to feature extraction and deep learning

Over the past decade, the use of artificial intelligence techniques in the field of health-monitoring has gained significant interest, especially for structures such as building and bridges. However, applications to industrial systems such as equipment-piping systems in nuclear plants have not been explored. Here, in this paper, it is shown that the existing techniques developed for buildings and bridges cannot be extended directly to equipment-piping systems as the response of such systems is governed by multiple localized modes unlike that in buildings and bridges. This paper proposes a new approach that consists of three key aspects: (i) a novel vector of degradation-sensitive features extracted from measured data, (ii) using a deep Artificial Neural Network (ANN) for diagnosis of degradation location and degradation severity, and (iii) consideration of uncertainty in degradation severity when training the ANN. Degradation in piping-equipment systems can occur due to flow-accelerated erosion and corrosion. These locations can potentially exhibit damage such as localized yielding or initiation of cracking due to an external event such as an earthquake. Moreover, such locations can at times go undetected by current inspection techniques. Therefore, a robust framework is needed for detection of degradation after a seismic event. This manuscript proposes a proof-of-concept framework, which utilizes data collected from sensors to generate a deep ANN database for predicting degraded locations and severity in a piping-equipment system. Degradation severity is classified as minor, moderate, and severe. In the suggested methodology, a novel vector of degradation-sensitive features is extracted from the sensor data to train the ANN. A simple piping-equipment system is selected to demonstrate feature extraction as a means to simplify pattern recognition, explore the design and parameters of an ANN, and develop a sensor placement strategy. The effectiveness of the proposed framework is demonstrated on a realistic primary safety system of a two-loop nuclear reactor. It is shown that the proposed post-hazard condition assessment framework is able to detect degraded locations along with the severity levels, including minor degradation, with considerably higher accuracy.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

Mechanism and kinetic study of rare earth extraction from allanite by direct acid leaching

Direct acid leaching was conducted to recover rare earth elements (REEs) from an allanite ore assaying 9,861.4 ppm of REEs. The effects of operational variables such as acid type, sulfuric acid (H 2 SO 4 ) concentration, temperature, solid/liquid (S/L) ratio, and particle size on the total REE (TREE) recovery were systematically examined. The REE mineralogy and the involved leaching mechanisms were investigated by microscopic characterization and residue re-leaching tests. It was found that approximately 80% of REEs was extracted using 1 M H 2 SO 4 at 75 °C for 2 h. Increasing temperature significantly improved the REE extraction, while changing acid type, H 2 SO 4 concentration, and particle size did not. The TREE recovery also gradually decreased at higher S/L ratios. The low fraction of Si leached (<4.0%) suggested that the extraction did not significantly alter the crystal structure of the dominant mineral. The leaching kinetics of REEs were fast within the first 10 min, followed by a much slower stage (i.e., 10-120 min). The kinetic modeling results showed that each stage may be controlled by both chemical reaction and diffusion (i.e., mix control). The activation energies for REE leaching using 1 M H 2 SO 4 in the 0-10 min and 10-120 min were determined to be 20.3 and 10.8 kJ/mol, respectively. Finally, the residue re-leaching results suggested that the fast leaching kinetics at the beginning may be explained by the preferential decomposition of metamict allanite rather than the formation of silica gel, while the following slower leaching stage was due to the dissolution of difficult-to-leach REE-bearing minerals such as well-crystallized allanite.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Development of a Flow-through Cell for Ultrasonic Extraction (UE)─Single Particle (SP)─ICP-MS─an Approach for Nano/Microparticle Elemental and Isotopic Analysis

Nanotechnology is a salient part of the scientific landscape, and analytical approaches are rapidly evolving to enable small-scale characterization of nano- and microparticle compositions and impurities. Here, a flow-through sonicating cell was developed for direct particle extraction from a silicon wafer and integrated with an inductively coupled plasma–mass spectrometer (ICP-MS) for subsequent elemental and isotopic characterization of the released particles. Ultrasonic extraction (UE)─single particle (SP)─ICP-MS offers controlled particle mobilization from solid substrates and allows for increased sample throughput by eliminating the need for pre-extraction of particles and decreasing sample preparation steps. Coupling this device to an ICP-MS with a time-of-flight (TOF) mass analyzer, it is possible to distinguish unique isotopic compositions of the particles. Both tungsten and nickel isotopically tagged particles, which were deposited on Si wafers, are presented here with analysis via UE─SP─ICP-MS. This approach could support efforts in the fields of particle synthesis, nuclear safeguards and forensics, environmental monitoring, and semiconductor industries in which the detection of particles from substrates and wafers is critical.

Paul, Molly [ORNL] (ORCID:0009000009672055)↗

Investigation of Electron Extraction and Protection Layers on Cu 2 O Photocathodes

Many semiconductor photoelectrodes used for solar fuel production require the addition of buffer and protection layers to enhance their solar-to-fuel conversion efficiency and long-term stability. For example, Cu 2 O, which is the most efficient oxide-based photocathode but suffers from photocorrosion, has been assembled with various buffer and protection layers to suppress photocorrosion and use more photoexcited electrons for useful reactions such as water reduction to H 2 . However, the abilities of various buffer and protection layers to extract electrons from Cu 2 O have never been directly evaluated. Instead, their abilities were estimated based on the photocurrent for water reduction after adding a hydrogen evolution catalyst on top of them. In these evaluations, as the photocurrent is affected not only by the buffer or protection layer but also by the catalyst, the ability of the buffer or protection layer to extract electrons from Cu 2 O could not be accurately determined or compared. Here, in this study, we demonstrate that 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPOL), whose reduction rate is faster than the photocorrosion rate of Cu 2 O, can be used as an effective electron scavenger to directly evaluate any change caused by a buffer or protection layer in electron-hole separation in Cu 2 O. In particular, we compared the performances of ZnO and TiO 2 layers on Cu 2 O for extracting electrons and suppressing photocorrosion. We also compared the performances of TiO 2 layers prepared by electrodeposition and atomic layer deposition (ALD) to show that the deposition method can make a striking impact on the performance of the same TiO 2 because it can affect the critical characteristics of the layer (e.g., defect levels, conductivity, interfacial atomic arrangements) that govern interfacial charge transfer in multilayer photoelectrodes.

36 MATERIALS SCIENCE↗

Electrochemical Recovery of Rare-Earth Elements from Coal Fly Ash Using Ionic Liquids as both Extractant and Electrolyte

Rare-earth elements (REEs) are critical for medical technologies, electronics, and clean energy. Coal fly ash (CFA), a byproduct of coal combustion, offers a promising alternative REE source. However, efficient extraction and separation of REEs from CFA remain challenging due to the complex composition of CFA. This study introduces a sustainable method for REE recovery using a recyclable ionic liquid, betainium bis(trifluoromethylsulfonyl)imide ([Hbet]- [Tf 2 N]), which serves both as the extractant from CFA and as the electrolyte in electrodeposition. In the first stage, [Hbet][Tf 2 N] preferentially extracts REEs from CFA through leaching. In the second stage, the REE-enriched ionic liquid undergoes electrochemical deposition using amperometry techniques, where REEs are reduced and deposited onto the electrode. The deposition experiments were conducted from −0.5 to −2.0 V vs a Pt quasireference electrode in a three-electrode setup comprising titanium as the working electrode and platinum as both the reference and counter electrodes. Varying the applied potential enabled potential-dependent preferential REE deposition. At −0.5 V, neodymium (Nd) showed preferential recovery, reaching 25% with a separation factor of 37 over other REEs. In contrast, applying a more negative potential increased overall deposition, yielding ∼50% Nd recovery and 10−20% recovery for the remaining REEs. After recovery, the ionic liquid was regenerated and reused for a subsequent electrochemical recovery cycle. Overall, this study demonstrates a feasible approach for REE recovery from CFA waste, with potential to enhance resource utilization within the REE supply chain.

coal fly ash↗

Flow-Assisted Selective Mineral Extraction from Seawater

The sustainable production of critical materials from natural sources requires a paradigm shift away from currently used resource-intensive processes. In this paper, we report a single-step, laminar co-flow method (LCM) that leverages non-equilibrium conditions to selectively extract pure Mg(OH) 2 from natural seawater. Conventional seawater-based Mg extraction involves adding individual or a combination of precipitants to obtain Mg(OH) 2 , but the co-existence of Ca 2+ unavoidably results in CaCO 3 impurities requiring additional purification steps. Here we show that the non-equilibrium conditions in LCM achieved using a microfluidics device and by simply co-injecting a NaOH solution with seawater can result in improved selectivity for Mg(OH) 2 unlike in conventional bulk mixing method. The resulting precipitates are characterized for composition and the process yield and purity are optimized through systematic variations of the reaction time and the concentration of NaOH. This is the first demonstration of LCM for selective separation, and as a one-step process that does not rely on novel sorbents, membranes, or external stimuli, it is easy to scale-up. LCM has the potential to be broadly relevant to selective separations from complex feed streams and diverse chemistries—enabling more sustainable materials extraction and processing.

54 ENVIRONMENTAL SCIENCES↗

Nanomaterial Synthesis Insights from Machine Learning of Scientific Articles by Extracting, Structuring, and Visualizing Knowledge

Nanomaterials of varying compositions and morphologies are of interest for many applications from catalysis to optics, but the synthesis of nanomaterials and their scale-up are most often time-consuming and Edisonian processes. Information gleaned from the scientific literature can help inform and accelerate nanomaterials development, but again, searching the literature and digesting the information are time-consuming manual processes for researchers. To help address these challenges, here we developed scientific article-processing tools that extract and structure information from the text and figures of nanomaterials articles, thereby enabling the creation of a personalized knowledgebase for nanomaterials synthesis that can be mined to help inform further nanomaterials development. Starting with a corpus of ~35k nanomaterials-related articles, we developed models to classify articles according to the nanomaterial composition and morphology, extract synthesis protocols from within the articles’ text, and extract, normalize, and categorize chemical terms within synthesis protocols. We demonstrate the efficiency of the proposed pipeline on an expert-labeled set of nanomaterials synthesis articles, achieving 100% accuracy on composition prediction, 95% accuracy on morphology prediction, 0.99 AUC on protocol identification, and up to a 0.87 F1-score on chemical entity recognition. In addition to processing articles’ text, microscopy images of nanomaterials within the articles are also automatically identified and analyzed to determine the nanomaterials’ morphologies and size distributions. To enable users to easily explore the database, we developed a complementary browser-based visualization tool that provides flexibility in comparing across subsets of articles of interest. We use these tools and information to identify trends in nanomaterials synthesis, such as the correlation of certain reagents with various nanomaterial morphologies, which is useful in guiding hypotheses and reducing the potential parameter space during experimental design.

36 MATERIALS SCIENCE↗

Impact of Water Extraction on Malonamide Aggregation: A Molecular Dynamics and Graph Theoretic Approach

Solution structure in liquid-liquid extraction affects the efficacy of separation; however, even for simplified organic phases, structural characterization and attribution of aggregation to intermolecular interactions are fundamental challenges. We investigate water uptake into organic phases for two malonamides commonly applied to actinide and lanthanide separations. Extracted water induces reorganization of the amphiphilic extractant molecules, although we find this rearrangement is not strongly manifested in small-angle X-ray scattering making it challenging to probe without methods such as atomistic simulation. Using a graph theoretic approach to define hydrogen bonded water/malonamide aggregates from molecular dynamics simulations, we find evidence of a characteristic aggregate size by water number that results from geometric accommodation of the surrounding malonamide molecules. Furthermore, this implies a degree of size selectivity inherent to these water-in-oil aggregates. Conversely, we find no evidence of a characteristic size of the aggregates with respect to their malonamide number. By defining a separate graphical representation of self-association of the amphiphilic malonamides, we quantify how water affects the local and nonlocal topology of the malonamide network, providing a basis for characterization of the structure and impact of polar solutes in increasingly complex organic phases.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Rational Construction of Porous Metal–Organic Frameworks for Uranium(VI) Extraction: The Strong Periodic Tendency with a Metal Node

Although metal-organic frameworks (MOFs) have been reported as important porous materials for the potential utility in metal ion separation, coordinating the functionality, structure, and component of MOFs remains a great challenge. Herein, a series of anionic rare earth MOFs (RE-MOFs) were synthesized via a solvothermal template reaction and for the first time explored for uranium(VI) capture from an acidic medium. The unusually high extraction capacity of UO2 2 + (e.g., 538 mg U per g of Y-MOF) was achieved through ion-exchange with the concomitant release of Me 2 NH 2 + , during which the uranium(VI) extraction in the series of isostructural RE-MOFs was found to be highly sensitive to the ionic radii of the metal nodes. That is, the uranium(VI) adsorption capacities continuously increased as the ionic radii decreased. Finally, in-depth mechanism insight was obtained from molecular dynamics simulations, suggesting that both the accessible pore volume of the MOFs and hydrogen-bonding interactions contribute to the strong periodic tendency of uranium(VI) extraction.

36 MATERIALS SCIENCE↗

An integrated in vivo/in vitro framework to enhance cell-free biosynthesis with metabolically rewired yeast extracts

Cell-free systems using crude cell extracts present appealing opportunities for designing biosynthetic pathways and enabling sustainable chemical synthesis. However, the lack of tools to effectively manipulate the underlying host metabolism in vitro limits the potential of these systems. Here, we create an integrated framework to address this gap that leverages cell extracts from host strains genetically rewired by multiplexed CRISPR-dCas9 modulation and other metabolic engineering techniques. As a model, we explore conversion of glucose to 2,3-butanediol in extracts from flux-enhanced Saccharomyces cerevisiae strains. We show that cellular flux rewiring in several strains of S. cerevisiae combined with systematic optimization of the cell-free reaction environment significantly increases 2,3-butanediol titers and volumetric productivities, reaching productivities greater than 0.9 g/L-h. We then show the generalizability of the framework by improving cell-free itaconic acid and glycerol biosynthesis. Our coupled in vivo/in vitro metabolic engineering approach opens opportunities for synthetic biology prototyping efforts and cell-free biomanufacturing.

59 BASIC BIOLOGICAL SCIENCES↗