Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “PURIFICATION”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 829 records · Page 46
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Adapting LEU-Modified Cintichem Process for Processing Up to 750 Grams of Uranium Targets

Argonne National Laboratory (Argonne) developed a low-enriched uranium (LEU)-modified Cintichem (LMC) process to enable production and purification of fission-produced molybdenum-99 (Mo-99) from LEU foil targets. This separation scheme starts with nitric acid (HNO 3 ) dissolution of irradiated LEU foil targets that yields an approximate final volume of 2 L. The dissolved uranium solution containing fission products, including Mo-99, is then treated by loading the solution on a titania-based recovery column to separate Mo-99 from bulk uranium. After several washing steps, Mo and other fission products are stripped from the titania column using sodium hydroxide (NaOH). The eluate is then acidified using nitric acid and subsequently processed for final purification using the LMC process. Uranium and most fission products are not adsorbed on the titania column but are eluted (i.e., removed using a solvent) during the wash steps; they can be purified and recycled into new uranium targets.

07 ISOTOPE AND RADIATION SOURCES↗
DOE OSTI2023

Multi-Sourced Collaboration for the Production and Refining of Rare Elements and Critical Metals (Final Technical Report)

The project objective was to develop a feasible and cost-effective method for recovering rare earth elements (REEs) and critical materials (CMs) from coal and coal byproducts, resulting in high-purity individually separated REEs and CMs. The targeted REEs included Y, Pr, Nd, Gd, Dy, and Sm, with a purity of over 99.5%, while the CMs included Co, Mn, Ga, Sr, Li, Ni, Zn, and Ge, with a purity of over 90%. The project aimed to design a prototype facility capable of producing 1-3 tonnes/day of high-purity REO mixes. The work was divided into four designated circuits: 1) REE extraction and concentration, 2) REE separation and purification, 3) RE metal production, and 4) CM production. To achieve these goals, the project involved 11 tasks, including technology reviews, research, process flow diagram development, mass balance estimation, and preliminary technical-economic analysis. The project team included researchers from the University of Kentucky, University of Alabama and Virginia Tech as well as process specialists from Argonne National Laboratory. MP Materials provided technical support regarding rare earth markets and processing while Alliance Coal performed resource assessment. The project included a market analysis for Nd/Pr, Tb, Dy, Gd, Y, Co, Mn, Li, Sr, Ga, Ni, Zn, and Ge. These analyses provided insights into the supply and demand trends as well as historic and future projections of market price relative to purity requirements for these elements. Two coal resources were selected for the project: the West Kentucky No. 13 (Baker) Seam and an undisclosed lignite resource in the Illinois coal basin. The estimated quantities of REEs in these resources were calculated based on production samples and drilling data. It was estimated that there is adequate supply for an operation producing one metric ton daily of higher purity mixed rare earth oxides (MREO) for approximately 20 years at a site located in western Kentucky. In Circuit 1, project data was obtained from a pilot heap leach and REE concentration facility. It was concluded that the existing circuit, which generated a MREO concentrate, two types of CM mixed products, and Li- and Sr-containing waters, would be suitable feed for circuits 2-4. Data from the first-of-its-kind coal coarse refuse heap leach pilot pad played a crucial role in estimating reliable elemental concentrations of the pregnant leaching solution (PLS). The average total REE concentration in the PLS was found to be 28.6 ppm. In Circuit 2, several concepts were explored including a novel process referred to as solvent-assisted chromatography (SAC). This concept involved a novel columnar reactor that incorporated multiple mixer/settlers, thereby enabling the operation of counter-flowing aqueous and organic phases. Unfortunately, due to project time constraints, a complete fundamental modeling analysis could not be completed to fully evaluate the technology. Molten salt electrowinning was considered as an alternative for circuit 3 following circuit 2 purification circuit utilizing the novel SAC process. A mass and energy balance of Nd reduction to metal in a fluoride containing molten salt electrolyte was conducted. Comparisons were made with the current state of Asian molten salt electrorefining, and potential improvements in siphoning rare earth metals (REM) from the reactor were presented. A cost estimate was performed for the production of 1 tonne per day, which yielded a total of $2.29 million for the nine electrowinning (EW) cells required. The selected option for circuits 2 and 3 was a plasma distillation process, which initially separates rare earth elements (REEs) from other elements. This is followed by selective electrowinning in various ionic liquids. The selection was made on the basis of thermodynamic modeling and experimental data previously published by a project partner. The combination offers an innovative approach to integrated refining and RE metal production. For Circuit 4, an extensive literature review was conducted for the processing of the CMs. The ultimate decision was to utilize a combined plasma and ionic liquid process as well to produce individual high-purity concentrates of Zn, Ni, Co, Mn, and Mg. A separate flowsheet for Li and Sr was recommended, which would yield carbonates of these elements. Due to the lack of suitable experimental data at this time, a process recommendation could not be provided but several methods have been proposed for consideration. Lastly, a techno-economic analysis (TEA) was conducted to assess the effectiveness of the proposed process for further investigation. The TEA results revealed a capital expense (CapEx) of $737 million and an annual operational expense (OpEx) of $220 million. Due to the selected elements, the hypothetical heap leach pad can produce 1 metric tonne per day of REO equivalent, but a conscious decision was made to only treat targeted REEs, resulting in the production of 0.4 metric tonne of REM. An estimated annual revenue of $90.87 million was projected based on standard market pricing information provided by the funding agency. During the TEA, ten different modules were evaluated for costing purposes. The precipitation circuit was identified as the largest single operational expense, followed by the Mg/Mn process due to the amount of treated metal. In terms of capital expenditures, the heap leach process incurred the highest cost, followed by the Mg/Mn process. The scalability of the plasma process is a crucial consideration since the reactors cannot be scaled beyond the largest demonstrated size due to their reliance on surface area of the slag and vapor phase. The purity estimate for the REEs are generally 98%±2% to produce a metal. The purity level being lower than the project objective was due to the lack of specific experimental data needed to tighten the tolerance of the estimates. Based on literature and previous experience, the CMs are estimated as follows; Ga (95%+, metal), Sr (95%+, carbonate), Li (95%+, carbonate), Ni (98%±2%, metal), Zn (95%+, metal sponge), Ge (95%+, metal), Co (98%±2%, metal), and Mn (98%±2%, metal).

01 COAL, LIGNITE, AND PEAT↗
DOE OSTI2023

Design of Muon Campus Full Flow Purifier for Varying Operational Conditions and Horizontal Shipping

The Muon Campus g-2 experiment requires stable helium supply at 5 K to the superconducting magnet. After a short period of operations, the pressure drop across the magnet’s flow supply valve increases due to impurities, resulting in reduced excess capacity concurrently with drop in refrigerator expander efficiency. This requires periodic powering down of the magnet to allow for helium valve “flush” to remove accumulated contamination at the valve as well as warming up the refrigerator expander above 80 K to release contamination. A “mobile” purifier is used for this periodic process but only at 10% of total refrigerator flow such that the purification process is extended. After long duration of running, this purification procedure is required almost every two weeks to restore proper liquid helium supply to the magnet. This shows requirement for full flow purifier which can purify impurities from entire Muon Campus refrigerator system and mitigate existing impurities issue and associated experiment downtime.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2023

Development and Testing of an Integrated Acid Mine Drainage (AMD) Treatment and Rare Earth/Critical Mineral Plant

The overall objective of this project was to design, construct, and test a pilot-scale continuous process for efficiently treating acid mine drainage (AMD) while producing rare earth element/critical mineral (REE/CM) concentrates. The process technology evaluated in this project included two distinct operations: 1. an upstream pre-concentration unit that treats raw AMD to environmentally compliant discharge standards while capturing an REE/CM preconcentrate, and 2. a downstream REE purification process that further enriches the pre-concentrate while producing mixed or partially separated rare earth oxides (REOs). The project team members successfully completed all of the proposed goals of the project and advanced the technology readiness levels (TRL) of the constituent operations to TRL 7 for the upstream concentration unit (full-scale system demonstration) and TRL 6 for the downstream purification process (pilot-scale demonstration).

01 COAL, LIGNITE, AND PEAT↗
DOE OSTI2024

Gas Stopper Developments for Improved Purity and Intensity of Low-Energy, Rare Isotope Ion Beams (Final Technical Report)

This final technical report summarizes the work of the Michigan State University (MSU) team supported by grant # DE-SC0021423 awarded by the Office of Nuclear Physics, Department of Energy. Objectives: The successful fulfillment of the FRIB science mission hinges on ensuring the availability of fast, stopped, and reaccelerated beams consisting of rare isotopes. This project's research and development focus was dedicated to supporting the advancement and creation of a cutting-edge linear gas stopper. The primary aim is to efficiently convert the high-intensity fast beams of rare isotopes provided by FRIB into high-quality, low-energy beams. These beams are essential for conducting stopped beam experiments or for subsequent reacceleration. The overarching goal is to advance technology, aiming to increase the beam rate capability of the linear gas stopper for medium-to-heavy-mass rare isotopes by more than tenfold compared to the currently most effective gas stopper in operation, and to improve the purity of the delivered beams. Project Description: The existing technology employed in gas stopping devices designed for low-energy, rare-isotope beams presents limitations in both the purity of extracted beams and the intensities of injected beams. These limitations are incompatible with the requirements of the recently commissioned rare isotope beam facility, FRIB. Our research and development efforts, aligned with the previously outlined objectives, focused on addressing the most critical aspects for enhancing beam-rate capability and purity. Specifically, advanced particle-in-cell simulations were developed and integrated into a simulation pipeline to explore the efficacy of multi-layer RF carpets on increasing ion transport efficiency with high incoming beam rates that generate space charge fields which can limit it. We also explored the possibility of using a collision-induced-dissociation (CID) gas cell to break up molecular contaminant ions that are generated during the stopping process. A prototype CID gas cell was constructed and tested with beams from an offline ion source, validating the concept with the successful demonstration of breaking of molecular ions. The outcome of this research enabled the formulation a conceptual design for a next-generation linear gas stopping device specifically tailored for FRIB. This device is envisioned to deliver rare-isotope-ion beams at a rate of 10 8 particles per second or higher, accompanied by advancements in purity. Methods employed: This project leverages advancements in technologies initially designed for the Advanced Cryogenic Gas Stopper (ACGS), the current state-of-the-art linear gas stopper, through the use of new simulations and beam purification via collision-induced-dissociation. The methods include: 1. Development of a prototype low-energy, low-pressure CID gas stopper. This prototype features a thin, approximately 20 nm, Si 3 N 4 entrance window designed for dissociating stable and rare-isotope molecular ions. The goal is to enhance beam purification and overall efficiency. 2. Creation of Particle-in-cell (PIC) simulations to assess the advantages of multi-layer RF carpets and multi-point extraction for ion transport efficiency. These simulations rely on the 3DCylPIC package, specifically designed for studying devices of this nature. The goal is to quantify and mitigate ion transport losses due to space charge generated in the stopping process of large numbers of ions. 3. Perform ion transport simulations across an RF carpet using an 8-phase travelling wave and evaluate its performance. Compared to the 4-phase RF carpets used in ACGS, the 8-phase carpets will double the wavelength of the generated traveling wave allowing for larger maximum RF amplitudes that could result in improved ion transport efficiency for high-intensity incoming beams when large space charge fields are present. Impact: Tackling the primary challenges associated with transforming high-energy projectile fragment beams into low-energy beams—specifically, addressing efficiency and purity—holds significant promise for advancing FRIB science. This advancement will particularly impact precision mass measurements, laser spectroscopy of short-lived nuclei, and studies in astrophysics and nuclear reactions using reaccelerated beams. These domains play a crucial role in addressing key questions outlined in the 2023 NSAC long-range plan, spanning nuclear structure, nuclear astrophysics, and fundamental symmetries. Additionally, they contribute to addressing 10 out of the 17 benchmarks identified by the NRC RISAC. The development of a next-generation gas stopping device capable of delivering low-energy, rare-isotope beams at a rate of 10 8 particles per second, or more, with high purity holds the potential to unlock experiments that would otherwise be unfeasible. Furthermore, it is expected to reduce the time required for experiments at FRIB, thereby maximizing scientific output. The research and development activities performed as part of this project bolstered essential competencies at FRIB in beam physics and ion source technologies, provided valuable training opportunities for junior scientists.

43 PARTICLE ACCELERATORS↗
DOE OSTI2024

Porous Organic Cage Membranes for Molecular Gas Separations (Final Technical Report for DE-SC0021357)

This proposal aims at demonstrating the development of a novel family of membranes, composed of porous organic cages (POC) which offer the possibility of displaying high separation performance for challenging molecular gas separations relevant to natural gas purification, and olefin/paraffin separation. The proposed POCs synthesized in membrane form will display the most desirable properties of polymers (facile processability and flexibility) and inorganic materials (hierarchically ordered pores with molecular sieving properties) leading to highly selective and permeable membranes. POCs should display distinctive structural, compositional, adsorption and transport properties than those of conventional porous materials, opening the doors for a new research direction in membrane science, and gas separations. Our preliminary results demonstrate the feasibility of preparing POC crystals with controlled size, and continuous POC membranes with remarkable high permeances, and separation ability for CO 2 /CH 4 , N 2 /CH 4 and C 3 H 6 /C 3 H 8 separations serving as a solid foundation for our proposed work. Fundamentally, this proposal aims at elucidating separation mechanisms of different gas mixtures related to natural gas composition, and olefin/paraffin separation over porous organic cage membranes. The proposed research will result in fundamental understanding of adsorption and transport properties of industrially relevant gas molecules through novel microporous membranes, and may lead to the development of a cost effective membrane technology for natural gas purification, and olefin/paraffin separation surpassing the conventional benchmark technology distillation. Furthermore, we aim at demonstrating selective water transport through POC membranes, which can be positively impactful in numerous industrial applications in which water is present. The ability to fabricate thin, chemically and mechanically stable POC membranes for societal relevant gas separations constitute a new and distinctive direction in membrane science. Our proposed work aims at addressing some of the challenges recognized in the Research Agenda for Transforming Separation Science . Specifically: (a) advancing understanding of complex mixtures on separation performance; (b) exploring thermodynamic and kinetic mechanisms through the elucidation of separation mechanisms, and (c) study potential stability issues of the membranes to be assessed by evaluating the long term membrane stability and performance at various temperatures and pressures. The team is uniquely qualified to execute the proposed work. The PI has solid expertise in the rational molecular engineering design of porous crystalline membranes for molecular gas separations. The PNNL collaborator has extensive experience in the synthesis, characterization, and functional applications of microporous crystals, with particular emphasis on gas adsorption.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

Regulating Gas Transport in Molecularly Engineered Polymer Membranes (Final Technical Report)

Energy-efficient separation processes are essential for a wide range of applications ranging from clean fuels (e.g., hydrogen purification) and petroleum refining (e.g., natural gas processing) to water purification and carbon capture. Membrane-mediated separations have shown tremendous promise in providing high productivity and high separation efficiency at significantly lower energy consumption, e.g., up to 90% less energy cost than traditional thermally driven processes such as distillation. Polymeric membranes–the dominant separation membrane materials–have yet to reach their full potential due to their limitations in long-term durability (e.g., productivity loss over the period of their lifetime due to physical aging) or insufficient stability under harsh conditions (e.g., high temperature, chemically complex feeds). This research seeks to establish a new paradigm in polymer membrane material design by harnessing crosslinked model networks with well-defined yet finely tailorable microstructure to facilitate fast and selective gas transport and simultaneously enhance membrane stability. Unlike traditional randomly crosslinked polymers, which suffer from structural inconsistencies and consequently suboptimal gas separation performance, crosslinked model network membranes prepared via a precisely controlled end-linking process enables the creation of previously unattainable microstructure tunability, which, in turn, results in versatile crosslinked membranes with high separation performance that meet the needs of various challenging gas separations. Using model network framework as a fundamental tool by applying this concept in diverse polymer categories, this work has led to the development of various innovative crosslinked membrane structures such as unimodal, bimodal and clustered model networks. These advanced crosslinked polymer membranes not only demonstrate exceptional gas separation performance that significantly outperform existing randomly crosslinked membranes, but also possess excellent long-term durability and robust stability under complex operating conditions. From a fundamental perspective, results from this research provide critical mechanistic insights into gas separation in crosslinked polymer membranes, addressing key knowledge gaps and opening new avenues for membrane design to meet various separation needs. The new membrane materials produced from this research enable the use of polymeric membranes for high temperature gas separations, offering substantial energy and cost savings by eliminating the need for repeated cooling-heating cycles in industrial processes.

02 PETROLEUM↗
DOE OSTI2025

Ensuring High-Purity Liquid Argon for the LBNF FDC: Collaborative Cryogenics Research Between UNICAMP and Fermilab

Ensuring High-Purity Liquid Argon for the LBNF FDC: Collaborative Cryogenics Research Between UNICAMP and Fermilab R. Doubnik1, M. Adamowski1, F. de M. Blaszczyk1, A. Hahn1, D. Montanari1, R. Mrowca1, Z. West1, C. Adriano2, T. P.M. Alegre2, D. Correia2, A. A. B. Machado2, E. Segreto2, R. G. Gonçalves3, E. M. Assaf6, J. M. Assaf3, D. Cardoso3, M. B. Fontes4, H. Da Motta4, D. Noriler5, P. J. G. Pagliuso2. 1 Fermi National Accelerator Laboratory, PO Box 500, Batavia IL 60510, United States. 2 “Gleb Wataghin” Institute of Physics, UNICAMP, Campinas-SP, 13083-859, Brazil. 3 CPqMAE - Research Center on Advanced Materials and Energy, Federal University of São Carlos (UFSCar), São Carlos, 13565-905, Brazil. 4 The Brazilian Center for Research in Physics (CBPF), Rio de Janeiro-RJ, 22290-180, Brazil. 5 School of Chemical Engineering, UNICAMP, Campinas-SP, 13083-859, Brazil. 6 São Carlos Institute of Chemistry, University of São Paulo, São Carlos-SP, 13566-590, Brazil. Email: rdoubnik@fnal.gov Abstract. The Long-Baseline Neutrino Facility (LBNF) located at the Sanford Underground Research Facility (SURF) in Lead, South Dakota, hosts the Deep Underground Neutrino Experiment (DUNE). This experiment employs cryostats containing nearly 70,000 metric tons of high-purity liquid argon (LAr). Ensuring LAr purity is critical for achieving the required electron lifetime, which directly impacts the experiment’s signal-to-noise ratio. The Horizontal Drift (HD) detector demands an electron lifetime exceeding 3 ms within its 3.5 m drift, equivalent to less than 100 parts-per-trillion (ppt) Oxygen contamination, while the Vertical Drift (VD) detector requires over 6 ms electron lifetime within its 6.0 m drift, corresponding to less than 50 ppt Oxygen contamination. To mitigate Nitrogen (N2) quenching of scintillation light, N2 contamination must remain below 1 ppm, as higher levels can result in up to a 20 % loss of light. The Brazil State University of Campinas (UNICAMP) significantly contributes to LBNF FDC through the development of argon purification and regeneration systems for HD and VD cryostats. UNICAMP designed and constructed the Purification Liquid Argon Cryostat (PuLArC), a small-scale test facility holding approximately 90 liters of LAr. Tests using PuLArC demonstrated that 1.2 kg of Li-FAU zeolite could reduce N₂ contamination from 20-50 ppm to 0.1-1.0 ppm within 1-2 hours. Tests at Fermilab’s Iceberg cryostat (2,596 liters) confirmed scalability, with 3 kg of Li-FAU reducing N₂ contamination from ~5 ppm to <1 ppm over 96 hours cycles without active circulation. This presentation will detail the research methods, test setups, and results, showcasing the potential of Li-FAU as an alternative to Molecular Sieve 4A for large-scale LAr systems. This advancement enhances DUNE's precision and demonstrates the impact of international collaboration on cryogenic research.

Doubnik, Roza [Fermilab]↗
DOE OSTI2025

Helium recovery system at IB3a

The increasing need for optimal and sustainable use of cryogenic resources to support Fermilab’s scientific mission has highlighted the necessity of improving the Laboratory’s helium management practices. An assessment of cryogenic test facilities identified the Technical Division’s Industrial Building 3a (IB3A) as a key site requiring upgrades to integrate a helium recovery system. The IB3A facility is essential for characterizing and testing superconductors, cables, and coils for various R&D projects, including the US High-Luminosity LHC Accelerator Upgrade Project (AUP), Mu2e, and other external collaborations. Currently, the facility relies on 500 L helium Dewars and vents the vaporized helium directly into the atmosphere, leading to significant helium loss. Given the non-renewable nature of helium, recovering and reusing this resource is critical for the sustainability of Fermilab’s operations. To address this challenge, a project has been initiated to connect IB3A to an existing helium purification station and refrigeration system located in another building via a dedicated pipeline pass over the roof of several buildings. This solution will enable the efficient capture of vented helium, its transfer to the purification station, and subsequent liquefaction for reuse in future operations. The project includes a detailed design phase, specifying the pipeline route, flow control mechanisms, and integration with the existing cryogenic infrastructure, followed by phased implementation and commissioning. By implementing this pipeline connection and upgrading IB3A, Fermilab aims to significantly reduce helium waste, lower operational costs, and align with its commitment to sustainability. This initiative provides a model for resource-efficient cryogenic operations and reinforces the Laboratory’s capacity to support its science mission for the long term.

Porwisiak, D. [Fermilab]↗
DOE OSTI2025

Bacterial Biomining Rare Earth Elements in Abandoned Coal Mine Drainage: Solubilization and Sequestration

Bacteria can be used to biomine rare earth elements (REEs) domestically from abandoned coal-mine drainage (AMD) solids. Pennsylvania has ~11,000 abandoned mines, with ~500 AMD passive remediation systems that precipitate AMD REE rich solids onsite. In passive systems, REEs, co-precipitate with manganese (Mn), accumulating as solids that can produce a valuable leachate when resolubilized. REEs like lanthanum (La) are used in battery technology. Microbial metabolic changes that co-resolubilize Mn and REEs could result in an affordable release process that does not require chemical additives and the select sequestering of REEs like La allow for the selective purification from a mixed REE composition. Currently, the microbial mechanisms that contribute to mass REE resolubilization and selective sequestration are poorly understood. We have isolated bacteria (Bacillus mycoides JR07 and Bacillus pseudomycoides KB7) that solubilize Mn oxide, La oxide, and AMD solids by acidogenesis. We have determined that isolates JR07 and KB7 solubilize the La from AMD PRS solids by their production of organic acids. Preliminary results show methylotrophic bacterial isolate B3 can take up soluble La(III), giving an avenue to purification of La from a rich REE leachate. Determining the microbial metabolism and genes involved in the mass resolubilization of REEs and selective biomining of La(III) is crucial to optimize the biomining of AMD solids. Our work addresses the growing need to develop novel REE recovery methods from domestic sources.

microbiology↗
DOE OSTI2025

Van de Graaff Irradiation Studies of Oxygen Sensor and Hydrated Zirconia Sorbent

Commercial-scale production of Mo-99 demands a facility-wide assessment of radiation-induced degradation across process equipment, instrumentation, and purification media. Key factors— total ionizing dose, dose rate, radiolysis-driven chemistry, thermal loads, activation, and any neutron-related effects—should inform material selection, shielding, and component layout. Purification materials (sorbents, resins, filters, seals, housing) require particular attention to ensure that irradiation does not alter selectivity or capacity, generate fines, or introduce leachables that could compromise Mo-99 purity or downstream Tc-99m generator performance. Dose mapping, accelerated irradiation testing, and studies of extractables/leachables together provide the basis for setting maintenance, calibration, and replacement intervals and for qualifying materials that retain mechanical integrity, chemical compatibility, and radiopurity over their service life.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Microbial Biomining for the Release and Recovery of Rare Earth Elements in Abandoned Coal Mine Drainage

Microbes can be used for biomining rare earth elements (REEs) from abandoned coal-mine drainage (AMD) solids. Domestically Pennsylvania has ~11,000 abandoned mines, with ~500 AMD passive remediation systems (PRSs) that precipitate REE rich solids. In passive systems, REEs, co-precipitate with manganese (Mn), accumulating as a valuable leachate when resolubilized. REEs like lanthanum (La) are used in battery technology. Microbial metabolism that co-resolubilize Mn and REEs could result in an affordable release process that does not require the addition of hazardous chemical additives. Microbial sequestering of La can be used for selective purification from a mixed REE composition. Currently, the microbial mechanisms that contribute to mass REE resolubilization and selective sequestration are poorly understood. We have isolated bacteria (Bacillus mycoides JR07 and Bacillus pseudomycoides KB7) that solubilize Mn oxide, La oxide, and AMD solids by acidogenesis. Preliminary results show methylotrophic bacterial isolate B3 can take up soluble La, which may have a potential application in the purification of La from a mixed REE leachate. Determining the microbial metabolism and genes involved in the REE resolubilization and selective biomining of La is crucial to optimize the biomining of AMD solids. Our work addresses the growing need to develop novel REE recovery methods from domestic sources.

microbiology↗
DOE OSTI2026

Progress Towards Synthesis of Uranium Chloride Fuel Salts Using Zinc Chloride

Reliable, scalable methods for producing high-purity actinide chloride salts are needed to support molten salt reactor fuel development and deployment. This report describes the continued development and demonstration of a bench-scale chlorination and purification apparatus using a zinc chloride-based method for synthesizing uranium chloride fuel salts. In this approach, uranium metal is chlorinated by ZnCl2 to produce LiCl-KCl-UCl3. Reaction with three aliquots of added uranium metal was used to generate a target uranium concentration of 30 wt %. While this concentration was chosen for initial testing of the apparatus and method, the final uranium concentration is not limited to 30 wt %. The zinc metal generated in the reaction forms an immiscible layer that was removed by volatilization at moderately high temperatures. Electrochemical measurements confirmed the removal of zinc and applied sensing methods indicated the uranium concentration to be approximately 25 wt %. These initial results demonstrate that the bench-scale chlorination apparatus is an effective platform for the synthesis and purification of uranium chloride salts using ZnCl2. This method shows promise for application to industry-relevant salt systems such as NaCl-UCl3. Further development is recommended to optimize reagent loading, zinc removal, and avoid possible U-Zn alloy formation.

Dulovic, Stephanie↗
DOE OSTI2022

Quantum algorithms from fluctuation theorems: Thermal-state preparation

Fluctuation theorems provide a correspondence between properties of quantum systems in thermal equilibrium and a work distribution arising in a non-equilibrium process that connects two quantum systems with Hamiltonians H 0 and H 1 = H 0 + V. Building upon these theorems, we present a quantum algorithm to prepare a purification of the thermal state of H 1 at inverse temperature β ≥ 0 starting from a purification of the thermal state of H 0 . The complexity of the quantum algorithm, given by the number of uses of certain unitaries, is $\mathcal{O}$ (e β(ΔA - w l )/2 ), where ΔA is the free-energy difference between H 1 and H 0 , and w l is a work cutoff that depends on the properties of the work distribution and the approximation error ϵ > 0. If the non-equilibrium process is trivial, this complexity is exponential i β∥V∥, where ∥V∥ is the spectral norm of V. This represents a significant improvement of prior quantum algorithms that have complexity exponential in β∥H 1 ∥ in the regime where ∥V∥$\ll$ ∥H 1 ∥. The dependence of the complexity in ϵ varies according to the structure of the quantum systems. It can be exponential in 1/ϵ in general, but we show it to be sublinear in 1/ϵ if H 0 and H 1 commute, or polynomial in 1/ϵ if H 0 and H 1 are local spin systems. The possibility of applying a unitary that drives the system out of equilibrium allows one to increase the value of w l and improve the complexity even further. To this end, we analyze the complexity for preparing the thermal state of the transverse field Ising model using different non-equilibrium unitary processes and see significant complexity improvements.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2022

Implementation of a Practical Teaching Course on Protein Engineering

Protein Engineering is a highly evolved field of engineering aimed at developing proteins for specific industrial, medical, and research applications. Here, we present a practical teaching course to demonstrate fundamental techniques used to express, purify and analyze a recombinant protein produced in Escherichia coli—the enhanced green fluorescent protein (eGFP). The methodologies used for eGFP production were introduced sequentially over six laboratory sessions and included (i) bacterial growth, (ii) sonication (for cell lysis), (iii) affinity chromatography and dialysis (for eGFP purification), (iv) bicinchoninic acid (BCA) and fluorometry assays for total protein and eGFP quantification, respectively, and (v) sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) for qualitative analysis. All groups were able to isolate the eGFP from the cell lysate with purity levels up to 72%. Additionally, a mass balance analysis performed by the students showed that eGFP yields up to 46% were achieved at the end of the purification process following the adopted procedures. A sensitivity analysis was performed to pinpoint the most critical steps of the downstream processing.

Gomes, Luciana (ORCID:0000000289921097)↗
DOE OSTI2023

Polymeric Membranes for H2S and CO2 Removal from Natural Gas for Hydrogen Production: A Review

Natural gas, an important source of hydrogen, is expected to be crucial in the transition to a hydrogen-based economy. The landscape of the gas processing industry is set to change in the near future with the development of highly acidic sour gas wells. Natural gas purification constitutes a major share of the gas separation membrane market, and the shift to low-quality sour gas wells has been mirrored in the trends of membrane material research. Purification also constitutes the major portion of the cost of natural gas, posing implications for the cost of hydrogen production. This review provides an update on the current state of research regarding polymeric membranes for H2S removal, along with CO2 separation, from natural gas that is used for hydrogen production via steam methane reforming. The challenges of adapting polymeric membranes to ternary H2S/CO2/CH4 separations are discussed in detail. Key polymeric materials are highlighted, and the prospects for their application in H2S removal from natural gas are evaluated. Finally, the growing interest in H2 production from H2S is discussed. Advances in the membrane industry and the emergence of new membrane materials may significantly improve the commercial viability of such processes.

Rao, Shraavya↗
DOE OSTI2022

Identification of Exported Plasmodium falciparum Proteins That Bind to the Erythrocyte Cytoskeleton

Plasmodium proteins are exported to the erythrocyte cytoplasm to create an environment that supports parasite replication. Although hundreds of proteins are predicted to be exported through Plasmodium export element (PEXEL)-dependent and -independent mechanisms, the functions of exported proteins are largely uncharacterized. In this study, we used a biochemical screening approach to identify putative exported P. falciparum proteins that bound to inside-out vesicles prepared from erythrocytes. Out of 69 P. falciparum PEXEL-motif proteins tested, 18 bound to inside-out vesicles (IOVs) in two or more independent assays. Using co-affinity purifications followed by mass spectrometry, pairwise co-purification experiments, and the split-luciferase assay, we identified 31 putative protein–protein interactions between erythrocyte cytoskeletal proteins and predicted exported P. falciparum proteins. We further showed that PF3D7_1401600 binds to the spectrin-binding domain of erythrocyte ankyrin via its MESA erythrocyte cytoskeleton binding (MEC) motif and to the N-terminal domains of ankyrin and 4.1R through a fragment that required an intact Plasmodium helical interspersed sub-telomeric (PHIST) domain. Introduction of PF3D7_1401600 into erythrocyte ghosts increased retention in the microsphiltration assay, consistent with previous data that reported a reduction of rigidity in red blood cells infected with PF3D7_1401600-deficient parasites.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2019

Defining Processing Times for Accelerator Produced 225Ac and Other Isotopes from Proton Irradiated Thorium

During the purification of radioisotopes, decay periods or time dependent purification steps may be required to achieve a certain level of radiopurity in the final product. Actinum-225 (Ac-225), Silver-111 (Ag-111), Astatine-211 (At-211), Ruthenium-105 (Ru-105), and Rhodium-105 (Rh-105) are produced in a high energy proton irradiated thorium target. Experimentally measured cross sections, along with MCNP6-generated cross sections, were used to determine the quantities of Ac-225, Ag-111, At-211, Ru-105, Rh-105, and other co-produced radioactive impurities produced in a proton irradiated thorium target at Brookhaven Linac Isotope Producer (BLIP). Ac-225 and Ag-111 can be produced with high radiopurity by the proton irradiation of a thorium target at BLIP.

07 ISOTOPE AND RADIATION SOURCES↗