Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “HCl”

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 433 records · Page 24
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Biosorption of copper from aqueous solutions utilizing agricultural wastes

Abstract The purpose of this study was to determine the copper (Cu) biosorption capacities of several agricultural wastes from aqueous solutions. Samples of agricultural wastes were tested unaltered and after hydrochloric acid (HCl) treatment. Additional parameters tested include sample dose, contact time, particle size, mixing temperature, and the concentrations and pH of the Cu solutions. Desorption studies were performed to determine if the removed Cu could be recovered. In addition, tests were conducted to determine if the agricultural waste samples (AWS) could be reused for additional Cu biosorption cycles. The results of this study demonstrate a wide range of Cu biosorption proficiencies ranging from 0% to 100% removal. The parameters that resulted in higher Cu removal include higher pH and lower Cu solution concentration. Desorption results showed a 58% to 86% Cu recovery rate. Three of the five reused AWS were effective at removing Cu during subsequent trials. Therefore, these AWS types can be reused for additional Cu biosorption cycles. Hence, it is possible that using those AWS for metal treatment could reduce hazardous waste disposal inefficiencies and costs by avoiding disposing of spent AWS following each Cu biosorption cycle.

Rizzuti, Anthony M.↗
DOE OSTI2023

Evaluation of two extraction chromatography resins for scandium and titanium separation for medical isotope production

Scandium-47 ( 47 Sc) can be used in nuclear medicine as a therapeutic-diagnostic, or "theragnostic," radioactive medical isotope for cancer detection and treatment. The 47 Sc isotope can be produced through the photonuclear reaction 48 Ti(γ,p) 47 Sc by irradiating enriched 48 Ti target material. The enriched target material necessary for production is costly; 48 TiO 2 costs ~ $\$$1550/g, and targets can be > 50 g ($\$$77,500) to produce medically relevant amounts of 47 Sc. In order to keep costs low, a highly efficient separation of scandium from bulk titanium is desired, along with efficient methods for recycling the target material. Here this research is focused on evaluating efficient methods for the separation of scandium from bulk quantities of titanium using commercially available diglycolamide-based and hydroxamate-based extraction chromatography resins (DGA resin and ZR resin, respectively). The sorption of 47 Sc and Ti on these resins were investigated at varying concentrations of HNO 3 , HCl, H 2 SO 4 , and HF to explore how they might be used in a large-scale production/processing setting.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
DOE OSTI2023

Determination of distribution coefficients of 41 elements in nitric and hydrochloric acids for actinide resin

The distribution coefficients of 41 elements were determined on Eichrom’s Actinide resin in HCl and HNO 3 solutions of molarities between 0.01 M and 9 M. Herein a separation scheme for these 41 elements was designed utilizing these distribution coefficients that combines the Actinide resin with Eichrom’s TRU resin. Overall, these values improve the ability to create separations targeting specific analytes utilizing Actinide resin.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
DOE OSTI2025

Actinium purification from elemental components of stainless steel and aluminum

Radioisotopes of actinium are valuable because of their potential use in the medical industry. Actinium-225 shows promise for treating disease—like cancer—via targeted alpha therapy (TAT), and the longer-lived actinium-227 is the parent of two radionuclides with potential application in TAT radiopharmaceuticals, thorium-227 and radium-223. Continuing progress in the development of these medical applications requires robust and diverse methods for extracting and purifying actinium from a wide range of matrices. Further, to define the strengths and limitations of separation methods commonly employed in actinium processing, we characterized the performance of ion exchange and extraction chromatographic steps for removing contaminants found in stainless steel (chromium, iron, nickel, and silicon) and aluminum from actinium-227. While AG-MP1 anion exchange resin with HCl (aq) successfully removed iron, cation exchanger AG 50W-X8 removed most other contaminants. The most persistent contaminant was aluminum, which was removed using a DGA Normal extraction resin. These results are presented within the context of applying that methodology toward actinium purification strategies.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Scalable synthesis of nanoporous silicon microparticles for highly cyclable lithium-ion batteries

Nanoporous silicon is a promising anode material for high energy density batteries due to its high cycling stability and high tap density compared to other nanostructured anode materials. However, the high cost of synthesis and low yield of nanoporous silicon limit its practical application. Here, we develop a scalable, low-cost top-down process of controlled oxidation of Mg 2 Si in the air, followed by HCl removal of MgO to generate nanoporous silicon without the use of HF. By controlling the synthesis conditions, the oxygen content, grain size and yield of the porous silicon are simultaneously optimized from commercial standpoints. In situ environmental transmission electron microscopy reveals the reaction mechanism; the Mg 2 Si microparticle reacts with O 2 to form MgO and Si, while preventing SiO 2 formation. Owing to the low oxygen content and microscale secondary structure, the nanoporous silicon delivers a higher initial reversible capacity and initial Coulombic efficiency compared to commercial Si nanoparticles (3,033 mAh/g vs. 2,418 mAh/g, 84.3% vs. 73.1%). Synthesis is highly scalable, and a yield of 90.4% is achieved for the porous Si nanostructure with the capability to make an excess of 10 g per batch. Our synthetic nanoporous silicon is promising for practical applications in next generation lithium-ion batteries.

25 ENERGY STORAGE↗
DOE OSTI2021

Assessing the Extractability of Rare Earth Elements from Coal Preparation Fines Refuse Using an Organic Acid Lixiviant

We report that this work is a first-order study to assess the suitability of an organic acid lixiviant to extract rare earth elements (REE) from coal preparation fines refuse sourced from a Pennsylvania mine with a total REE of ~ 300 ppm. The extraction of REE using an organic acid, in this case 0.1 M citric acid and 0.5 M trisodium citrate solution, is compared against 0.5 M (NH 4 ) 2 SO 4 , 1 M HCl, 1.2 M H 2 SO 4 , and 0.5 M ethylenediaminetetraacetic acid (EDTA). Ashing the coal waste material prior to leaching tests with the citrate solution nominally improved REE extraction. Buffered citrate solution recovered 7% of the total REE in the as-received Isabella Fines as compared to 11% in ashed samples, whereas (NH 4 ) 2 SO 4 extracted 5–6%, respectively. EDTA recovered up to 33% of the total REE, most likely due to the higher coordination chelate bond. Mineral acids, however, outperformed the organic acids on ashed material (16–52% REE recovery), suggesting that organic acids may not be a suitable competitive option for REE extraction from these types of feedstocks.

01 COAL, LIGNITE, AND PEAT↗
DOE OSTI2021

Sequentially prepared Mo-V-Based SCR catalyst for simultaneous Hg 0 oxidation and NO reduction

Molybdenum (Mo)-vanadium (V)-based selective catalytic reduction (SCR) catalyst synthesized by the sequential impregnation of Mo and W followed by V was investigated for simultaneous elemental mercury (Hg 0 ) oxidation and nitrogen oxide (NO) reduction in an existing SCR unit with respect to different TiO 2 phases, calcination temperatures, flue gas constituents, gas velocities, and reaction temperatures. Anatase phase TiO 2 and the calcination temperatures of 400 and 500 degrees C resulted in similar to 69% Hg 0 oxidation at 10 ppmv HCl and 350 degrees C. The high calcination temperature of 700 degrees C resulted in TiO 2 phase transformation from anatase to rutile and agglomeration. The modified SCR catalyst prepared with the impregnation sequence of Mo and W followed by V using anatase TiO 2 and calcination temperature 500 degrees C showed similar to 99% Hg 0 oxidation and 87% NO reduction conversions at an NH 3 /NO molar ratio of 0.9 under 350 degrees C and 5,000 hr -1 space velocity in typical sub-bituminous and lignite coal simulated flue gases. Finally, the effects of these parameters and conditions were further investigated using various characterization techniques including BET, TEM, XRD, NH 3 TPD and XAFS.

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

Evaluation of hydroxamate-based resins towards a more clinically viable 44 Ti/ 44 Sc radionuclide generator

For this research, several hydroxamate-based resins were synthesized and tested for use in 44 Ti/ 44 Sc generator systems in small scale experiments (740 kBq 44 Ti). The most promising resin was tested further in larger scale generator studies (37 MBq). This resin displayed impressive retention of 44 Ti over several elutions, and high quantities of 44 Sc were obtained in small volumes of dilute HCl eluents. Initial radiolabeling experiments were conducted and demonstrated the possibility of direct radiolabeling of the generator produced 44 Sc with DOTA.

07 ISOTOPE AND RADIATION SOURCES↗
DOE OSTI2025

Separation of terbium from proton-irradiated gadolinium oxide targets – development of an effective, scalable and automatable process

This work reports an effective and scalable radiochemical separation process for isolating terbium from Gd 2 O 3 . The separation process uses three commercially available extraction chromatography resin columns, has been implemented on a computer-controlled chemistry module, and tested with 100 mg quantities of proton-irradiated nat Gd 2 O 3 . Here, the 4-hour separation procedure isolated radioterbium in 1.3 mL of 0.01 M HCl with 80 ±8% radiochemical yield and a Gd decontamination factor >(1.2 ± 0.3)·10 5 .

Adjacent lanthanide separation↗
DOE OSTI2025

48 Ca(p,pn) 47 Ca linac production for the preparation of a 47 Ca/ 47 Sc generator

Here, the production of 47 Sc via the nuclear reaction 48 Ca(p,pn) 47 Ca→(β-, T 1/2 = 4.54 d) 47 Sc and the assembly of a 47 Ca/ 47 Sc generator system has been investigated at Brookhaven National Laboratory. To produce 47 Ca, a pressed nat CaCl 2 target was irradiated with a proton beam at energy on target of 27.5 MeV at Brookhaven Linac Isotope Producer. Irradiated targets were dissolved in water and then acidified with concentrated HCl before separation using extraction chromatography through a diglycolamide (DGA) resin column. After ingrowth, 47 Sc was collected at >90 % with low contamination from both nonradioactive metals and coproduced radionuclides. A total of four 47 Ca/ 47 Sc separations were performed with 6–7 days between the irradiation and the separation to allow the equilibration of the ingrowing 47 Sc.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
DOE OSTI2026

Processing iridium foil targets for the production of radioplatinum isotopes

Dissolving noble metals remains challenging because of their high reduction potentials and tendency to passivate as oxides. This barrier is acute for iridium metal targets used to produce platinum radioisotopes, where post-irradiation processing is costly and hazardous with conventional routes. Here, we report a rapid alkali-fusion method that converts Ir metal directly into chloride media compatible with downstream separations. In the process, an Ir foil is fused with Na 2 O 2 and KCl at temperatures above the KCl melting point; the molten salt enhances heat transfer and facilitates O 2− /Na + transport to the Ir surface, overcoming Ir's oxidation resistance. The fused cake is then cooled and leached in 10 M HCl, yielding Ir in solution without specialized microwave digestion or HF. Pt separation from bulk Ir was evaluated using extraction-chromatography resins. A newly formulated ionic-liquid resin containing Cyphos IL 104 (E104) was compared with two commercial resins (TrisKem TK200 and TK201). All resins achieved >90 % Ir recovery. Pt co-recovery depended on resin chemistry: TK200 recovered 85.9 % Pt, TK201 recovered 54.1 % Pt, and E104 recovered 72.9 % Pt. This study introduces a fast, scalable dissolution route for solid Ir targets and demonstrates resin choices that tune Ir/Pt separation, lowering the barrier to routine production and purification of Pt radioisotopes.

07 ISOTOPE AND RADIATION SOURCES↗
DOE OSTI2022

Tin sensitization and silver activation on indium tin oxide surfaces

Adhesion of electrical contacts on electronic and optoelectronic devices is important for reliable device operation. Sn-sensitization is a widely used process that improves uniformity and adhesion of plated metals to glass and polymer surfaces. Electrically conductive substrates can significantly benefit from improved uniformity, adhesion, and contact resistance to metallic contact layers. In this study, we investigate the process of Sn-sensitization and Ag-activation on indium tin oxide (ITO) surfaces—a dominant transparent conducting oxide used in optoelectronic devices. Here, our results show that ITO films exposed to Sn-sensitization solutions with HCl concentrations below 10 mM effectively modify the surface termination through the process of Sn-sensitization (Sn-bonding at the surface hydroxide sites) without etching the ITO film. However, the subsequent Ag-activation on an ITO surface does not seem to follow the typical response on a glass substrate, suggesting that Ag-activation of an ITO surface is likely limited by the Ag ion size relative to the area density of surface hydroxide sensitization sites.

42 ENGINEERING↗
DOE OSTI2020

Oxidation kinetics of biochar from woody and herbaceous biomass

The goal of this study was to determine oxidation kinetics for biochar produced from fast pyrolysis of various biomass feedstocks. In particular, the role of inherent ash content on the oxidation rate was evaluated. Thermogravimetric analysis (TGA) and fluidized bed combustion experiments were used to explore oxidation kinetics of six fast pyrolysis produced biochars with diverse ash content. Here, the reaction rates varied by a factor of three under chemical kinetic-limited conditions, demonstrating inorganic content impacts oxidation rate. Chemical kinetic rate coefficients were proposed as a function of compositional parameters to determine overall fit and impact. Potassium content was found to have a positive correlation, best describing the differences in the oxidation kinetic rate coefficients. Additionally, feedstocks were subjected to a 1 M HCl acid wash mitigating the catalytic activity of the metals. Acid washed biochars had lower oxidation kinetic rates compared to their unwashed counterparts, indicating the removal of catalytically active metals reduced oxidation rate. Gas composition (CO/CO 2 ) was measured during fluidized bed experiments for both acid-washed and unwashed biochars, which varied between the six biochars. Formation of CO 2 was greatly affected by catalytic metals, finding potassium content to correlate well with a higher percentage of CO 2 formation as compared to CO. Comparison of oxidation rates were made between the two experimental apparatuses to measure the effect of attrition on biochar oxidation.

09 BIOMASS FUELS↗
DOE OSTI2026

Mobility of heavy rare earth elements in magmatic-hydrothermal systems: Experimental determination of DyPO 4 solubility in supercritical fluids

Dysprosium (Dy) is part of the heavy rare earth elements (REE) and a critical component in the production of high-performance super magnets used in wind turbines, electric vehicles, and other green technologies. The HREE phosphate, xenotime, is commonly associated with hydrothermal systems, where the mobility, fractionation, and deposition of REE are controlled by the stability of aqueous complexes and solubility of REE minerals which depend on temperature, pressure, and fluid composition (salinity, pH, and ligand availability). Here, we conducted a series of synthetic DyPO 4 solubility experiments in NaCl-HCl-bearing aqueous solutions (pH of 2 at 25 °C) from 500 to 700 °C and 1.5 kbar using externally heated pressure vessels. DyPO 4 displays a strong prograde solubility with temperature across all studied fluid salinities (0–0.5 m NaCl). The DyPO₄ solubility isotherms at 500 °C, 600 °C, and 700 °C show a complex relationship with salinity where DyPO₄ solubility is highest (39.2–1552 ppm at 500–700 °C) in 0 m NaCl solutions, decreases strongly (21–331 ppm at 500–700 °C) in the 0.06 m NaCl solutions and remains relatively constant in the 0.25 m (42.8–248 ppm) and 0.5 m NaCl (40.2–124 ppm) solutions. Thermodynamic modeling suggests that pH increases as a function of temperature and salinity, and controls solubility due to the stability of chloride complexes (i.e., DyCl +2 and DyCl 2 + ) at 500–600 °C, transitioning to hydroxyl complexes (i.e., Dy(OH) 3 0 ) dominating at 700 °C and relatively alkaline pH. Comparison with NdPO 4 solubility data indicates that the light REE in monazite is significantly more soluble than the heavy REE in xenotime in saline fluids at high temperature (500–700 °C), implying efficient light/heavy REE fractionation in supercritical fluids. The lower solubility of DyPO 4 relative to NdPO 4 suggests that at high temperatures, acidic (pH 2–4), low-salinity (∼5 wt% NaCl) fluids will favor the precipitation of xenotime over monazite as it will cool from 700 °C to below 500 °C. These observations align with paragenetic mineral assemblages in NYF pegmatites (e.g., Baveno, Italy), where xenotime commonly immobilizes heavy REE during the high-temperature hydrothermal stages.

58 GEOSCIENCES↗
DOE OSTI2020

Extraction chromatography of 225 Ac and lanthanides on N,N-dioctyldiglycolamic acid /1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide solvent impregnated resin

The alpha-emitter 225 Ac (t 1/2 = 9.92 d) is currently under development for targeted alpha-particle therapy of cancer, and accelerator production of 225 Ac via proton irradiation of thorium targets requires robust separations of 225 Ac from chemically similar fission product lanthanides. Additionally, the lanthanide elements represent critical components in modern technologies, and radiolanthanides such as 140 Nd (t 1/2 = 3.37 d) also have potential application in the field of nuclear medicine. The ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Bmim][NTf 2 ]), combined with the diglycolamide extractant, N,N-dioctyldiglycolamic acid (DODGAA), was adsorbed on macroporous resin support to produce a solvent impregnated resin (SIR) that was investigated for separations of 225 Ac and lanthanides. The equilibrium distribution coefficients (Kd) of the rare earth elements (Sc(III), Y(III), Ln(III)), 225 Ac(III), Th(IV), and U(VI) on the prepared DODGAA/[Bmim][NTf 2 ]-SIR were determined from batch adsorption experiments in HCl and HNO 3 media. The DODGAA/[Bmim][NTf2]-SIR exhibited preferential uptake of the heavier lanthanide elements while allowing for the separation of the lighter lanthanides. Column separations utilizing the DODGAA/[Bmim][NTf 2 ]-SIR were effective at separating the lighter lanthanides from each other, and separating 225 Ac from a mixture of lanthanides, 213 Bi, and 225 Ra without the need for additional complexing agents.

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

Determination of transition metal ions in fossil fuel associated wastewaters using chelation ion chromatography

Here, this study outlines the development and subsequent validation of a method using chelation ion chromatography (CIC) pretreatment followed by traditional ion chromatography (IC) and post column UV/vis detection to measure transition metals in fossil fuel wastewaters, such as oil & gas (O&G) brines and coal mine drainage (CMD) waters. Measurement of transition metals is often an important characterization step in the research of environmental and energy systems. IC represents one way to measure these metals with the advantages of being versatile, simple and relatively low cost compared to other analytical methods. However, high concentrations of alkali and alkaline earth metals present in fossil fuel wastewaters will decrease IC detectability of transition metals in these waters. In this study, a CIC method was developed for the analysis of transition metal ions (Fe 3+ , Cu 2+ , Ni 2+ , Zn 2+ , Co 2+ , Mn 2+ , and Fe 2+ ) in fossil fuel associated wastewaters such as Appalachian CMD and O&G wastewaters from the Permian and Bakken shale basins in the United States. CIC system incorporated an on-line chelator column (e.g., the MetPac CC-1) with high selectivity for transition metals over alkali and alkaline earth metals for salt matrix removal prior to transition metal separation and detection. Additional method developments also included acidifying all samples to 2% v/v HCl and using gradient elution rather than isocratic. The recoverability of transition metals in simple salt solutions commonly found in CMD and brine samples (e.g. NaCl, Na 2 SO 4 , CaCl 2 ) using CIC was evaluated and compared to that using traditional IC. Our results found that the CIC system significantly improved transition metal recoveries for samples in 10,000 mg/L CaCl 2 matrix, reaching 87%-108% recovery for all analytes, as opposed to 2-323% recovery in traditional IC. The limits of detection in this study achieved 10.09 – 161.2 μg/L, comparable to reported values in similar IC studies. The developed method was also verified with certified water samples, resulting in 89% - 111% recoveries in samples with higher analyte concentrations (i.e. >4x the LoDs). The developed method achieved 87% -112% recoveries for most analytes in CMD samples and 72%-138% recoveries for Bakken shale samples, relative to ICP-MS values. Overall, the current IC method can be a very good screening tool for fast and cheap analysis for transition metals at mg/L level, to facilitate selection of samples for more detailed ICP-MS analysis.

01 COAL, LIGNITE, AND PEAT↗
DOE OSTI2024

Development of a SnO 2 -based 44 Ti/ 44 Sc generator for medical applications

Towards application of 44 Sc for diagnostic nuclear medicine, a 44 Ti/ 44 Sc generator based on an inorganic resin has been evaluated. Unlike other radionuclide generators used for medical applications, the long-term retention of the parent 44 Ti is vital due to its long half life. In this work, tin dioxide (SnO 2 ), a robust inorganic-based resin, has been synthesized and used as the stationary phase for a 44 Ti/ 44 Sc generator. The sorption behavior of 44 Ti/ 44 Sc was tested on SnO 2 with varying acids, concentrations, and times. Preliminary batch study results showed >88 % 44 Ti retention to the resin at lower acid concentrations (0.05 M HNO 3 and 0.05 M HCl). A pilot generator was evaluated for a year, demonstrating 85.3 ± 2.8 % 44 Sc elution yields and 0.71 ± 0.14 % 44 Ti breakthrough in 5 M HNO 3 . Based on capacity studies, a 7.4 MBq (200 µCi) upscaled generator system was constructed for further evaluation of the SnO 2 resin stability and the efficacy of the eluted 44 Sc for radiolabeling. 44 Sc could be regularly eluted from this generator in 5 M HNO 3 with an overall average radiochemical yield 84.7 ± 9.5 %. Post-elution processing of the 44 Sc with DGA-normal resin removed all 44 Ti present and allowed for high 44 Sc-DOTA labeling yields of 94.2 ± 0.5 %. Overall, SnO 2 has been shown to be a viable material for a 44 Ti/ 44 Sc generator.

07 ISOTOPE AND RADIATION SOURCES↗
DOE OSTI2023

Influence of native oxide film on corrosion behavior of additively manufactured stainless steel 316L

The influence of the native oxide film on passive film properties and localized corrosion of additively manufactured SS 316L was studied in 1 wt% HCl by XPS characterization, electrochemical polarization curves, and post-test morphology analysis by SEM. Increased Cr oxidation kinetics was observed in the as-polished sample with the native oxide film resulting in formation of an overall more protective and compact film compared to the cathodically-activated sample. Electrochemical analysis showed that corrosive attack varied between dislocation cell boundaries to cell interiors depending on the initial surface state and polarization conditions. In conclusion, a corrosion mechanism is proposed to explain this variation.

36 MATERIALS SCIENCE↗