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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 91 records · Page 5
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Effects of fluorinated solvents on electrolyte solvation structures and electrode/electrolyte interphases for lithium metal batteries

Electrolyte is very critical to the performance of the high-voltage lithium (Li) metal battery (LMB), which is one of the most attractive candidates for the next generation high-density energy storage systems. Electrolyte formulation and structure determine the physical properties of the electrolytes and their interfacial chemistries on the electrode surfaces. Localized high-concentration electrolytes (LHCEs) outperform state-of-the-art carbonate electrolytes in many aspects in LMBs due to their unique solvation structure. Types of fluorinated co-solvents used in LHCEs are investigated here in searching for the most suitable diluent for high concentration electrolytes (HCEs). Non-solvating solvents (including fluorinated ethers, fluorinated borate and fluorinated orthoformate) added in HCEs enable the formation of LHCEs with high-concentration solvation structures. However, low solvating fluorinated carbonate will coordinate with Li+ ions and form a second solvation shell or a pseudo-LHCE which diminishes the benefits of LHCE. In addition, it is evident that the diluent has significant influence on the electrode/electrolyte interphases (EEIs) beyond retaining the high-concentration solvation structures. Diluent molecules surrounding the high-concentration clusters could accelerate or decelerate the anion decomposition through co-participation of diluent decomposition in the EEI formation. The varied interphase features lead to significantly different battery-performance. This study points out the importance of diluents and their synergetic effects with the conductive salt and the solvating solvent in designing LHCEs. These systematic comparisons and fundamental insights into LHCEs using different types of fluorinated solvents can guide further development of advanced electrolytes for high-voltage LMBs.

Cao, Xia↗
DOE OSTI2014

Radiolytic Treatment of the Next-Generation Caustic-Side Solvent Extraction (NGS) Solvent and its Effect on the NGS Process

We show in this work that the solvent used in the Next Generation Caustic-Side Solvent Extraction (NGS) process can withstand a radiation dose well in excess of the dose it would receive in multiple years of treating legacy salt waste at the US Department of Energy Savannah River Site. The solvent was subjected to a maximum of 50 kGy of gamma radiation while in dynamic contact with each of the aqueous phases of the current NGS process, namely SRS-15 (a highly caustic waste simulant), sodium hydroxide scrub solution (0.025 M), and boric acid strip solution (0.01 M). Bench-top testing of irradiated solvent confirmed that irradiation has inconsequential impact on the extraction, scrubbing, and stripping performance of the solvent up to 13 times the estimated 0.73 kGy/y annual absorbed dose. Lastly, stripping performance is the most sensitive step to radiation, deteriorating more due to buildup of p-sec-butylphenol (SBP) and possibly other proton-ionizable products than to degradation of the guanidine suppressor, as shown by chemical analyses.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
DOE OSTI2020

Extraction, Scrub, and Strip Test Results for the Salt Waste Processing Facility Caustic Side Solvent Extraction Solvent Sample

An Extraction, Scrub, and Strip (ESS) test was performed on a sample of Salt Waste Processing Facility (SWPF) Caustic-Side Solvent Extraction (CSSX) solvent and salt simulant to determine cesium distribution ratios (D (Cs) ), and cesium concentration in the strip effluent (SE) and decontaminated salt solution (DSS) streams; this data will be used by Parsons to help determine if the solvent is qualified for use at the SWPF. The ESS test showed acceptable performance of the solvent for extraction, scrub, and strip operations. The extraction D (Cs) measured 13.2, exceeding the required value of 8. This value is consistent with results from previous ESS tests using similar solvent formulations. Similarly, scrub and strip cesium distribution ratios fell within acceptable ranges

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2022

Comparing the extraction performance of cyclodextrin-containing supramolecular deep eutectic solvents versus conventional deep eutectic solvents by headspace single drop microextraction

A headspace single drop microextraction (HS-SDME) method coupled with high performance liquid chromatography was developed to compare the extraction of eighteen aromatic organic pollutants from aqueous solutions using cyclodextrin-based supramolecular deep eutectic solvents (SUPRADESs) and alkylammonium halide-based conventional deep eutectic solvents (DESs). Different derivatives of beta-cyclodextrin (β-CD) were employed as hydrogen bond acceptors (HBA) in SUPRADESs and the extraction performance investigated. SUPRADES comprised of the 20 wt% native β-CD HBA provided the highest enrichment factors of analytes compared to SUPRADESs comprised of other derivatives of β-CD (random methylated β-cyclodextrin, heptakis(2,3,6-tri-O-methyl)-β-cyclodextrin, and 2-hydroxypropyl β-cyclodextrin). In addition, native β-CD and its derivatives were dissolved in the neat DESs and their effect on the extraction of analytes examined. Dissolution of 20 wt% native β-CD in the choline chloride ([Ch + ][Cl - ]):2Urea DES resulted in a significant increase in the extraction efficiencies of target analytes compared to the neat [Ch + ][Cl - ]:2Urea DES. Under optimum conditions, the extraction method required a solvent microdroplet of 6.5 μL, 1000 rpm stir rate, 30% (w/v) salt concentration, and a temperature of 40 °C. The tetrabutylammonium chloride: 2 lactic acid DES resulted in the highest enrichment factors while the [Ch + ][Cl - ]:2Urea DES had the lowest for most of the analytes among the evaluated solvents. The method provided limits of detection (LODs) down to 35 μg L -1 . Finally, the developed method was applied for the analysis of spiked tap and lake water, where relative recoveries ranging from 83.7% -119.7% and relative standard deviations lower than 19.2% were achieved.

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

Integrated Approach to CO 2 Capture and Conversion to Cyclic Carbonates under Solvent- and Additive-Free Conditions Utilizing the CO 2 Capture Solvent EEMPA

An integrated CO 2 capture and conversion to materials (IC 3 M) implementation utilizing a CO 2 capture solvent is an efficient approach to reduce the amount of CO 2 in the atmosphere while producing value-added chemicals. In this work, we demonstrate that the advanced water-lean CO 2 capture solvent, N-(2-Ethoxyethyl)-3-morpholinopropan-1-amine (EEMPA), can catalyze the cycloaddition reaction between CO 2 and propylene oxide to produce the value-added chemical propylene carbonate in an IC 3 M fashion. When excess propylene oxide is used relative to EEMPA, yields as high as 75% with 85% selectivity toward propylene carbonate can be achieved under solvent-free conditions without the need of additives/cocatalysts. The reaction temperature (120 °C) is comparable to that used in the thermal regeneration of the capture solvent under industrial conditions. Formation of an undesired amino alcohol side product was observed, but it may be reversible or avoidable with continued research despite the unsuccessful initial attempts. Finally, we show that this can be applied to other epoxides for the production of various cyclic carbonates.

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

Axial H-Bonding Solvent Controls Inhomogeneous Spectral Broadening, While Peripheral H-Bonding Solvent Controls Vibronic Broadening: Cresyl Violet in Methanol

The dynamics of the nuclei of both a chromophore and its condensed-phase environment control many spectral features, including the vibronic and inhomogeneous broadening present in spectral line shapes. For the cresyl violet chromophore in methanol, we here analyze and isolate the effect of specific chromophore–solvent interactions on simulated spectral densities, reorganization energies, and linear absorption spectra. Employing both chromophore and its condensed-phase environment control many spectral features, including the vibronic and inhomogeneous broadening present in spectral line shapes. For the cresyl violet chromophore in methanol, we here analyze and isolate the effect of specific chromophore–solvent interactions on simulated spectral densities, reorganization energies, and linear absorption spectra. Employing both force field and ab initio molecular dynamics trajectories along with the inclusion of only certain solvent molecules in the excited-state calculations, we determine that the methanol molecules axial to the chromophore are responsible for the majority of inhomogeneous broadening, with a single methanol molecule that forms an axial hydrogen bond dominating the response. Furthermore, the strong peripheral hydrogen bonds do not contribute to spectral broadening, as they are very stable throughout the dynamics and do not lead to increased energy-gap fluctuations. We also find that treating the strong peripheral hydrogen bonds as molecular mechanical point charges during the molecular dynamics simulation underestimates the vibronic coupling. Including these peripheral hydrogen bonding methanol molecules in the quantum-mechanical region in a geometry optimization increases the vibronic coupling, suggesting that a more advanced treatment of these strongly interacting solvent molecules during the molecular dynamics trajectory may be necessary to capture the full vibronic spectral broadening.

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

Nitroxide Radical Polymer–Solvent Interactions and Solubility Parameter Determination

Redox-active polymers such as macromolecular nitroxide radicals have been studied as electrode materials for organic batteries and electronics. Polymer–solvent interactions are essential to processing and device performance, but macromolecular nitroxide radical–solvent interactions are currently not well described. In this work, the Hildebrand and Hansen solubility parameters of poly(2,2,6,6-tetramethylpiperidinyloxy-4-yl methacrylate) (PTMA), oxidized PTMA (PTMA + ), and PTMA’s precursor (PTMPM) are determined using both experimental and group contribution methods for the first time. This work indicates that the hydrogen-bonding Hansen solubility parameter (δ h ) and the solubility sphere radii (R) provide the best prediction of the macromolecular radical’s interaction with solvents. From these solubility parameters, the group contribution values for the nitroxide and oxoammonium cation were then calculated. It is shown that this information allows for the prediction of polymer–solvent interactions for other nitroxide-based macromolecular radicals. Lastly, the discovered solubility parameters are used to predict PTMA electrode formulations for batteries that outperform controls.

36 MATERIALS SCIENCE↗
DOE OSTI2016

Probing effect of solvent concentration on glass transition and sub-T{sub g} structural relaxation in polymer solvent mixtures: The case of polystyrene-toluene system

A novel experimental method for the analysis of volume relaxation induced by solvents in glassy polymers is presented. A gravimetric technique is used to evaluate the isothermal solvent mass uptake at controlled increasing/decreasing solvent pressure at constant rate. Fundamental properties of the solvent/polymer system can be obtained directly, and models can be applied, combining both nonequilibrium thermodynamics and mechanics of volume relaxation contribution. The fundamental case of polystyrene and toluene mixtures are thus accounted for, and various experimental conditions have been explored, varying the temperature, and spanning over different pressure increase/decrease rates. The results obtained allowed to evaluate the isothermal second order transition induced by solvent sorption, as well as the determination of the effect of the pressure rate. Therefore, this work proposes a new standard for the characterization and the understanding of the relaxational behavior of glassy polymers.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2017

Hierarchical calibration and validation framework of bench-scale computational fluid dynamics simulations for solvent-based carbon capture. Part 2: Chemical absorption across a wetted wall column: Original Research Article: Hierarchical calibration and validation framework of bench-scale computational fluid dynamics simulations

Part 1 of this paper presents a numerical model for non-reactive physical mass transfer across a wetted wall column (WWC). In Part 2, we improved the existing computational fluid dynamics (CFD) model to simulate chemical absorption occurring in a WWC as a bench-scale study of solvent-based carbon dioxide (CO 2 ) capture. In this study, to generate data for WWC model validation, CO 2 mass transfer across a monoethanolamine (MEA) solvent was first measured on a WWC experimental apparatus. The numerical model developed in this work can account for both chemical absorption and desorption of CO 2 in MEA. In addition, the overall mass transfer coefficient predicted using traditional/empirical correlations is conducted and compared with CFD prediction results for both steady and wavy falling films. A Bayesian statistical calibration algorithm is adopted to calibrate the reaction rate constants in chemical absorption/desorption of CO 2 across a falling film of MEA. The posterior distributions of the two transport properties, i.e., Henry's constant and gas diffusivity in the non-reacting nitrous oxide (N 2 O)/MEA system obtained from Part 1 of this study, serves as priors for the calibration of CO 2 reaction rate constants after using the N 2 O/CO 2 analogy method. Finally, the calibrated model can be used to predict the CO 2 mass transfer in a WWC for a wider range of operating conditions.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2019

Membrane assisted continuous production of solvents with integrated solvent removal using liquid-liquid extraction

The aim was to demonstrate an industrially relevant pilot scale integrated process to produce butanol and other solvents from lignocellulosic sugars produced with AVAP® biomass fractionation technology from southern pine wood. The concentrated sugars were concurrently fermented using genetically engineered Clostridium acetobutylicum to n-butanol, acetone, isopropanol and ethanol in continuous membrane assisted cell recycle fermentation with steady-state solvent productivity exceeding 10 g/L/h. The solvents from the cell free permeate were recovered with extractant of butyl butyrate in a continuous liquid-liquid extraction column and aqueous product (raffinate) along with unused sugars, nutrients, and metabolic intermediates were recycled back to the fermentors. The total solvent yield approached 0.30 g/g sugars.

09 BIOMASS FUELS↗
DOE OSTI2020

Synthesis of porous organic cage CC3 via solvent modulated evaporation

We demonstrate a Humidity Modulated Solvent Evaporation (HMSE) approach to promote the nucleation and growth of CC3 crystals. This approach relies on the gradual evaporation of dichloromethane (solvent) from a diluted concentration of CC3 precursors deposited on aluminum foil. The slow solvent evaporation allowed enough time for the organization and formation of CC3 porous organic cage. The solvent diffusion rate was modulated by the relative humidity in the system. The slow kinetics implied during the development of CC3 phase, allowed the formation of CC3 crystals. HRTEM, SAED, SEM, and XRD patterns were used as pivotal characterization techniques to follow and confirm the formation of CC3 crystals.

porous organic cages, modulated evaporation, cryst↗
DOE OSTI2025

Solvent-Free Melt-Processed Cathode Mitigates Li Anode Instability in Polymer-Based Solid-State Batteries

Solvent-free manufacturing of battery components is a promising alternative to traditional slurry processing for reducing the cost and environmental impact. In this work, we used twin-screw melt extrusion to fabricate a polymer-based high voltage composite cathode. The melt-processed cathode is dense (near zero porosity) and thick (65 μm) and has high active material loading (80 wt %). The active particles are distributed uniformly throughout the melt-processed cathode, unlike the traditional slurry-cast cathode, which exhibits inhomogeneous particle distribution. In the melt-processed cathode, polymer and carbon form separate phases, whereas in the slurry-cast cathode they blend into a single phase. Due to these structural differences, the melt-processed cathode shows smooth charge–discharge profiles, while the slurry-cast cathode shows noisy charging and soft-shorting behavior. In conclusion, this work highlights that twin-screw extrusion as a scalable, solvent-free manufacturing method is advantageous in producing uniform cathodes, which mitigates anode instability.

25 ENERGY STORAGE↗
DOE OSTI2017

Effect of HEH[EHP] impurities on the ALSEP solvent extraction process

In solvent extraction processes, organic phase impurities can negatively impact separation factors, hydrolytic performance, and overall system robustness. The resulting inconsistent performance can affect the process-level viability of a separation concept, and thus knowledge of the impurities present, their effects on the process, and how to remove them are vital. Deleterious impurities may be introduced into a system from reagent synthesis, or result from degradation via radiolysis and hydrolysis during use. In this work, the acidic extractant, 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP])—proposed for application in extractive processes aimed at separating trivalent minor actinides from lanthanides and other fission products—is characterized with respect to its common impurities and their impact on Am(III) stripping in the Actinide Lanthanide SEParation (ALSEP) system. Furthermore, to control impurities in HEH[EHP], existing purification technologies commonly applied for the acidic organophosphorus reagent were assessed and a new chromatographic purification method specific to HEH[EHP] is presented.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Density of Next-Generation Caustic-Side Solvent Extraction Solvent

This report recommends the appropriate modifier concentration to employ in the Next Generation Solvent (NGS) to be used in the Salt Waste Processing Facility (SWPF) at the Savannah River Site for removal of cesium from legacy tank waste. The Next Generation Caustic-Side Solvent Extraction (NG-CSSX) process employing the NGS is a marked improvement over the original Caustic-Side Solvent Extraction (CSSX) process, as it provides more effective removal of cesium from highly alkaline radioactive wastes and concentrates this removed cesium into an aqueous solution that is easy to vitrify for final disposal. Considerable effort has been devoted to optimizing the chemistry and process conditions of both systems, and their effectiveness has been demonstrated at the pilot scale at the Modular CSSX Unit (MCU). Due to the success of the demonstration and pilot-scale tests, the Salt Waste Processing Facility (SWPF) has been built to process larger volumes of waste with the CSSX process. To accelerate the waste-processing rate of the SWPF beyond its design throughput, plans call for the replacement of the CSSX process by the NG-CSSX process. To implement the NG-CSSX process in equipment optimized for CSSX, adjusting the density of the NGS to match the CSSX solvent density of 0.851 ± 0.0008 g/mL is considered advisable to obtain comparable hydraulic performance. Toward this objective, the density of the NGS has been measured at different temperatures and modifier concentrations to determine that a concentration of 0.650 M Cs-7SB modifier provides the best match for the desired density.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2023

The Compatibility of Tefzel™ and Viton™ B with Caustic-Side Solvent Extraction Solvents

The Salt Waste Processing Facility (SWPF) plans to switch from the current Caustic-Side Solvent Extraction (CSSX) solvent to the Next Generation Solvent-Phase II (NGS-Phase II). SRNL was requested to evaluate the compatibility between polymeric materials of construction at SWPF and NGS-Phase II solvent. The work presented here concentrated on two materials of interest: Tefzel™ and Viton™ B.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗