Mixture Of Sulfide Research Articles

Ionic conductivity and thermal stability of lithium salt / potassium bifluoride electrolytes for thermal batteries

The incorporation of potassium bifluoride (KF–HF) as an additive to the lithium-halide electrolyte for thermal batteries was investigated. Different mixtures of lithium fluoride, lithium chloride and lithium sulfide with KF-HF were studied using electrochemical impedance spectroscopy and differential scanning calorimetry. The results from these tests were combined to obtain a better understanding of the relationship between ionic conductivity, melting point, and electrolyte composition. The results indicated that it is feasible to maintain a relatively high ionic conductivity at temperatures lower (250–300 °C) than current thermal battery electrolytes (400–550 °C). Mixtures of lithium fluoride and potassium bifluoride provided the best ionic conductivity at 260 °C. The effect of mixing these lithium halides on the thermal decomposition of the KF-HF was also investigated. It was observed that it can increase decomposition temperature by up to 15 °C while at the same time reduce the melting point of the mixture and increase the ionic conductivity.

Synthesis and study of structure and phase composition in Cu2–xS, SnxSy, ZnS, CuxSnSy and CuZnSnS pellets

Synthesis of pure single-phase Cu2ZnSnS4 (CZTS) has attracted much attention of some laboratories and investigation centers around the world. This is important in order to eliminate secondary phases which are detrimental to the final conversion efficiency of the CZTS solar cells. Pseudo-ternary phase diagram showed the formation of pure CZTS using the mixture of Cu2S, SnS2 and ZnS binary sulfides; nevertheless, the gap is very narrow. An additional problem lies in the effective determination of the CZTS purity, because some secondary phases display similar X-ray diffraction and Raman spectra as those of CZTS. The present work addresses a simple, fast and economical synthesis method for the preparation of some binary, ternary and CZTS pellets, which were prepared from their corresponding co-precipitated powders. These tablets can be used not only as a sputtering target but also as a precursor in a solid-state reaction. Among the various prepared compounds, Cu2−xS–SnxSy–ZnS and CuxSnSy are included and characterized to identify their presence in the CZTS pellets. From the obtained results, the usefulness of co-precipitation as a method to produce highly pure single-phase CZTS is discussed.

Error Estimate for Lidar Measurements of Concentration during Probing of Atmospheric Mixtures of Hydrogen Sulfide and Methane Molecules

A variant of lidar for Raman scattering of light is proposed for installation on a pilotless flying platform. It is shown that for sensing at a laser wavelength of 405 nm and flying altitudes of up to 500 m, gaseous mixtures of molecules of hydrogen sulfide and methane can be measured by this method at concentrations below 1.4·1011 cm–3 over times of 10 s and 1 ms. Results of a numerical solution of the lidar equation for 180° Raman scattering of the gaseous mixture are presented for probing in the atmospheric boundary layer for molecular hydrogen sulfi de and methane at concentrations ranging from 1010–1016 cm–3 with synchronous photon counting employing a flying platform at altitudes up to 500 m.

Oxidative Cross-Coupling of Cysteamine with Secondary Phosphine Chalcogenides: Aspects of Reaction Chemoselectivity

Cysteamine (2-aminoethanethiol) undergoes oxidative cross-coupling with secondary phosphine sulfides and phosphine selenides under mild conditions (room temperature, 2–5 h, CCl4/Et3N) to give products of monocoupling at the amino group (ethylchalcogenophosphinic amides with free SH functions) and dicoupling (l-chalcogenophosphorylamino-2-chalcogenothioethanes) in 72–85% total yield. Under similar conditions, stirring an equimolar mixture of bis(2-phenylethyl)phosphine sulfide (or selenide), 1-butylamine, and 1-butanethiol leads to the chemoselective formation of the corresponding chalcogenophosphinic amides in high yield.

An integrated diagnostic approach to Max Ernst's painting materials in his Attirement of the Bride

Abstract The Attirement of the Bride, painted by Max Ernst in 1940, is permanently on display in the Peggy Guggenheim Collection (PGC) in Venice. Within the framework of a larger study of materials and techniques of works by Ernst at the PGC, researchers carried out a series of non-invasive analyses. A combined approach based on Vis-NIR multispectral imaging, Raman Spectroscopy, X-Ray Fluorescence (XRF), and External Reflection Fourier Transform Infrared Spectroscopy (ER-FTIR), was conducted insitu in the museum galleries. In addition, two micro-samples were analysed with SEM-EDS and μ-Raman. This approach produced vital information on the preparatory drawing, the pentimenti, the pigments, the extenders and the alteration products present in the painting. The results showed also the presence of a white preparatory layer, under the pictorial one and above the canvas, composed by lithopone (a mixture of zinc sulphide and barium sulphate), basic lead carbonate and calcium carbonate. The latter compound is probably present also as an extender. The palette included both traditional and new synthetic, commercial pigments, used as primary colours or in mixtures. Moreover, in several areas of the painting, zinc oxalates have been identified as alteration products and more rarely, zinc metal soaps, which could also be present as additives in the paint tube. These analyses revealed the masterful and innovative painting technique of this pioneer of Surrealism.

Lidar Probing of a Mixture of Hydrogen Sulfide and Methane Molecules in the Atmosphere from a Flying Platform

The results of numerical solution of the lidar equation for the Raman scattering on the molecules of a gas mixture of hydrogen sulfide and methane in the 180° direction when probing the molecules of hydrogen sulfide and methane in the atmospheric boundary layer with concentrations in the range of 1010–1016 cm–3 from a flying platform at altitudes of up to 500 m in the synchronous photon counting mode are presented. It is shown that concentrations of the studied hydrogen sulfide and methane molecules below the level of the maximum permissible concentration (MPC) for such a version of the Raman scattering lidar can be recorded within a measurement time of 10 s when probing at a laser radiation wavelength of 405 nm and a platform flight height in the range of up to 500 m.

Corrosion and Cavitation Erosion Behaviours of Cast Nickel Aluminium Bronze in 3.5% NaCl Solution with Different Sulphide Concentrations

The effect of sulphide (Na2S) concentration (SC) on the corrosion and cavitation erosion behaviours of a cast nickel aluminium bronze (NAB) in 3.5% NaCl solution is investigated in this study. The results show that when the SC exceeds 50 ppm, the hydrogen evolution reaction dominates the cathodic process, and a limiting current region appears in the anodic branch of the polarisation curve due to the formation of a copper sulphide film, which is a diffusion-controlled process. After long-term immersion, the increased mass loss rate of NAB with the sulphide additions of 20 and 50 ppm is attributed to the less protective films, which contains a mixture of copper oxides and sulphides. Moreover, NAB undergoes severe localised corrosion (selective phase corrosion, SPC) at the β′ phases and eutectoid microstructure α + κIII. By comparison, NAB undergoes general corrosion and a copper sulphide film is formed in 100 and 200 ppm sulphide solutions. Cavitation erosion greatly increases the corrosion rate of NAB in all solutions and causes a negative potential shift in 3.5% NaCl solution due to the film destruction. However, a positive potential shift occurs in the solutions with SC higher than 50 ppm due to the accelerated mass transfer of the cathodic process. The cavitation erosion mass loss rate of NAB increases with the increase of SC. The occurrence of severe SPC decreases the phase boundary cohesion and causes brittle fracture under the cavitation impact. The corrosion–enhanced erosion is the most predominant factor for the cavitation erosion damage when the SC exceeds 50 ppm.

An efficient method for removing hydrogen sulfide from natural gas using supersonic Laval nozzle

A new method was proposed for hydrogen sulfide removal from natural gas through the utilization of supersonic flow in a Laval nozzle. For this purpose, a mathematical model was established for the supersonic non-equilibrium condensation flow of the binary methane-hydrogen sulfide mixture. The condensation parameters were numerically calculated and described in detail, and a sensitivity analysis was carried out to investigate the influence of the inlet parameters on the supersonic condensation flow. The results show that when the inlet temperature and pressure were 290K and 5MPa respectively, and the mole fraction of hydrogen sulfide was 15%, the removal efficiency of hydrogen sulfide was 64.83%, which indicates that the use of supersonic separation technology for this application is indeed feasible. It was also found that with the decrease of inlet temperature or the increase of inlet pressure, the nucleation site moved forward (i.e. closer to the throat), and the maximum droplet radius and liquid mass fraction of hydrogen sulfide increased. When the mole fraction of hydrogen sulfide was less than 5%, however, the liquid mass fraction of hydrogen sulfide was almost zero. Therefore, it appears that using a reasonable hydrogen sulfide fraction, a lower inlet temperature, and a higher inlet pressure can promote the supersonic condensation of hydrogen sulfide in the Laval nozzle and improve the efficiency of the removal process. These results suggest that supersonic separation technology can provide an efficient and environment-friendly way to remove hydrogen sulfide from natural gas, thereby reducing emissions.

Study of flow-assisted corrosion (FAC) in a API 5L X-70 steel in a brine-H2S–CO2 system using the rotating cylindrical electrode

Corrosion caused by the mixture CO2/H2S in the transport of hydrocarbons is one of the most important research areas in the energy industry due to the severe problems it produces during the wear and tear of the pipes. Based in previous studies, in the present investigation the corrosion of API 5L X-70 steel in media with CO2 and H2S is studied as well as mixtures of both media, by means of a rotating cylindrical electrode due to the need to know the behavior of corrosion products in metals. The corrosion rate is evaluated at different pressures of H2S and CO2 and at 30 and 60 °C using the potentiodynamic polarization resistance measurements. From the results, it is observed that steel at the conditions of 0.8 bar H2S + 0.2 bar CO2 at 30 °C, yielded the lowest corrosion rate. This behavior is attributed to the fact that when H2S predominates it allows the formation of a greater number of protective layers comprised by a mixture of oxides, sulfides, sulfates and carbonates as corrosion products.

Application of the loop method to the preparation of gas reference material

High-accuracy gas reference material is an important prerequisite to guaranteeing the accuracy of stoichiometry. At present, however, the existing procedures of preparing gas reference material are complicated and time-consuming with high degree of uncertainty, so it is difficult to realize the high-accuracy measurement of gas compositions. In this paper, a loop method of preparing the gas reference material was developed. Then, its uncertainty degree on trace materials and preparation process was assessed and compared with the preparation process of the traditional dilution method. Finally, its weighing value was verified by means of a gas chromatography. And the following research results were obtained. First, the weighing cylinder of traditional preparation methods need a balance of wide range and low precision, so the uncertainty degree in the weighing process is introduced many times by multi-stage dilution. Second, when the loop method is adopted to prepare mixed gas reference material, the preparation can be completed in one step, so the uncertainty degree introduced in the preparation process is decreased by one order of magnitude. Third, by virtue of the loop method, the previously-used preparation procedures are simplified, the consumption of raw material is reduced and the preparation efficiency of mixed gas reference material is increased. Fourth, the loop method has been successfully applied to the preparation of gas reference material of natural gas and sulfide mixtures, and it is promising in more extensive application to realize efficient preparation and accurate valuing of gas reference material. And fifth, a gas chromatography is used to verify the nominal value of mixed gas reference material prepared by the loop method. And it is indicated that the loop method is of strong feasibility and accuracy.

Preparation and effect of complexing agents on ternary FeZnS2 thin films by chemical bath deposition method for photo catalytic degradation of dye molecules

In the present paper the studies on iron zinc sulphide thin films that have been deposited at room temperature on to the glass slides by chemical bath deposition technique using a solution mixture of ferrous sulphate, zinc sulphate, sodium sulphide, EDTA and Leishman stain is reported. Both EDTA and Leishman stain act as complexing agents and are expected to play a main role in the growth of FeZnS2 thin films. The structure of FeZnS2 thin films analysed by X-ray diffraction (XRD) study reveal that the thin films have a multi crystalline feature together with a solid three dimensional appearances at room temperature. The microstructure and the surface texture of the deposited filmsare characterised using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The SEM images show that the deposited films have a fine texture due to the presence of complexing agents. AFM studies revealed that the grain size of the deposited films to be around 80–100 nm with the thickness being approximately uniform. FTIR spectral studies of the thin films were recorded between 400 and 7000 cm−1. FeZnS2 thin films illustrated excellent optical properties with great absorbance in the visible region. The band gap value found to be 2.37–2.77 eV. The Hall Effect measurements show that the FeZnS2 thin films to have a n-type behaviour which exhibits p-type behaviour after the addition of complexing agents which is an ideal condition for solar cell applications. Towards this direction, the photo catalytic activities of FeZnS2 thin films were also assessed by the degradation of crystal violet, malachite green and methylene blue in aqueous solution under sun light irradiation.

Status of the URAN array for detection of EAS neutron component

First prototypes of PRISMA-32 neutron detectors based on the ZnS (Ag) scintillator demonstrated the perspectives of their application for detection of neutrons in extensive air showers. Detected thermal neutrons are generated due to interactions of the hadronic component with the nuclei of the atmosphere or the matter surrounding the detector and carry important information about the energy of primary particles. A mixture of zinc sulfide with natural boron (ZnS + B2O3) is used in the URAN setup. Detectors of the URAN array are located on the roofs of NEVOD and neighboring laboratory buildings; the area of each detector is 0.36 m2. The array consists of independent clusters of 12 detectors in each and is united by a central station of collection and processing of information. Two new clusters of the array were put into operation in 2017, synchronization with other NEVOD setups (NEVOD-EAS array and NEVOD-DECOR-SCT) was provided, and collection of experimental data was started with the area of about 103 m2. The first events of the EAS with neutrons have been registered and data on the temporal distribution of EAS neutrons have been obtained.

Enhancing the performance of sulfurized polyacrylonitrile cathode by in-situ wrapping

Sulfurized Polyacrylonitrile (S-PAN) has garnered extensive attention as cathode materials for LiS batteries in recent years because of its advantages such as high sulfur utilization efficiency, high Coulombic efficiency and low self-discharge rate. However, it is difficult to effectively balance the conflict between a high S loading (> 45wt%) and cycling stability for S-PAN. In this work, we employed an in situ wrapping method to improve the cycling performance of high-S-content S-PAN. Compared with the unwrapped S-PAN, the capacity retention ratio of the wrapped S-PAN cathode increased from 38% to 62% after 100cycles at 0.25C. The analyzed results suggested that the wrapping layer on the high-S-content S-PAN may compose a mixture of sulfide, inorganic LiBxOy and some organic compounds.

A Numerical Study on the Effect of Temperature and Composition on the Flammability of Methane–Hydrogen Sulfide Mixtures

ABSTRACTThe growing demand of natural gas inspires existing and new projects in topographical areas where the hydrocarbon extraction meets severe safety challenges due to the presence of hydrogen sulfide (H2S) in natural gas, i.e. sour gas. Indeed, the combined effect of flammability and toxicity of such gases has the critical potential to increase the hazard level in the industrial installation, thus aggravating the consequences for human and assets.In this work, a detailed kinetic model was validated and adopted to estimate the laminar burning velocity and the flammability limits of sour gas at different initial temperatures, within the range 250–325 K, equivalence ratio from 0.4 to 2.5, and content of H2S up to 15%v/v with respect to methane. For larger amount of the acid, almost negligible variations of the burning velocity of the mixtures have been observed, even if slight variations are detected either at lean (decrease) or rich (increase) conditions. On the contrary, flammability limits results show also that the addition of H2S has a strong relevance on safety parameters, more specifically for the upper flammability limit.

Лидарное зондирование смеси молекул сероводорода и метана в атмосфере с летающей платформы

The back scattering Raman lidar equation for the gas mixture of the hydrogen sulfide and the methane molecules numerical solution results are presented at the hydrogen sulfide and methane molecules remote sensing in the atmospheric boundary layer with the concentration in the range of 1010 cm-3 … 1016 cm-3 from the flying platform at the heights up to 500 m in the synchronous photon counting lidar mode. It has been shown that the studied hydrogen sulfide molecules concentration at the level of 1,4 1011 cm-3 can be registered during measurement time duration of 10 s and the methane molecules concentration of 7,6 1015 cm-3 - during measurement time of 1 ms for such a lidar variant at the 405 nm laser radiation wavelength and the platform flight altitude up to 500 m.

Error estimation of the hydrogen sulfide and methane molecules mixture in the atmosphere lidar sensing concentration measurements

Error estimation of the hydrogen sulfide and methane molecules mixture in the atmosphere lidar sensing concentration measurements

Adaptation of granular sludge microbial communities to nitrate, sulfide, and/or p-cresol removal.

Effluents from petroleum refineries contain a toxic mixture of sulfide, nitrogen, and phenolic compounds that require adequate treatment for their removal. Biological denitrification processes are a cost-effective option for the treatment of these effluents, but the knowledge on the microbial interactions in simultaneous sulfide and phenol oxidation in denitrifying reactors is still very limited. In this work, microbial community structure and macrostructure of granular biomass were studied in three denitrifying reactors treating a mixture of inorganic (sulfide) and organic (p-cresol) electron donors for their simultaneous removal. The differences in the available substrates resulted in different community assemblies that supported high removal efficiencies, indicating the community adaptation capacity to the fluctuating compositions of industrial effluents. The three reactors were dominated by nitrate reducing and denitrifying bacteria where Thiobacillus spp. were the prevalent denitrifying organisms. The toxicity and lack of adequate substrates caused the endogenous decay of the biomass, leading to release of organic matter that maintained a diverse although not very abundant group of heterotrophs. The endogenous digestion of the granules caused the degradation of its macrostructure, which should be considered to further develop the denitrification process in sulfur-based granular reactors for treatment of industrial wastewater with toxic compounds.

Experimental study of sulfur solubility in silicate–carbonate melts at 5–10.5 GPa

Sulfur solubility in Ca–Mg–Fe silicate–carbonate melt was experimentally determined at 5–10.5 GPa and 1400–1600 °C. Melt was produced by reaction between natural carbonates (calcite and magnesite) and San Carlos olivine (XFo ~ 0.9), which was used as a container, and equilibrated with either Fe-Ni sulfide liquid under reducing conditions (in the presence of graphite) or CaSO4 liquid under oxidizing conditions (Re–ReO2 buffer). To overcome the problem of the presence of sulfide droplets within the silicate–carbonate melt and to reverse the equilibrium, two sample configurations were employed: (1) a carbonate–sulfide mixture placed in the center of the olivine container and (2) sulfide placed in the olivine container and carbonate initially positioned outside the container near the wall of the external Pt capsule. In the former case, silicate–carbonate melt with suspended sulfide melt droplets infiltrated through the olivine capsule, and the two melts were separated owing to their different physical properties. In the latter case, silicate–carbonate melt migrated through thin fractures in the olivine container to come into contact with sulfide. The results of the two experimental series constrained the solubility of sulfide S in silicate–carbonate melt at 0.02–0.10 wt%. The S-solubility increases with increasing FeO content in the melt and is less sensitive to pressure, temperature and other compositional parameters. The solubility of S in the presence of the Re–ReO2 buffer is much higher (up to 2–3 wt%) and dominated by S6+. The obtained results indicate that S is relatively inert during carbonate mantle metasomatism under reduced conditions, but can be transported under oxidizing conditions.

VUV Photodeposition of Thiol-Terminated Films: A Wavelength-Dependent Study.

Photoinitiated chemical vapor deposition (PICVD) has become attractive for selective and specific surface functionalization, because it relies on a single energy source, the photons, to carry out (photo-) chemistry. In the present wavelength (λ)-dependent study, thiol (SH)-terminated thin film deposits have been prepared from gas mixtures of acetylene (C2H2) and hydrogen sulfide (H2S) via PICVD using four different vacuum-ultraviolet (VUV) sources, namely, KrL (λpeak = 123.6 nm), XeL (λpeak = 147.0 nm), XeE (λpeak = 172.0 nm), and Hg (λ = 184.9 nm) lamps. Different λ influence the deposition kinetics and film composition, reflecting that photolytic reactions are governed by the gases' absorption coefficients, k(λ). Thiol concentrations, [SH], up to ∼7.7%, were obtained with the XeL source, the highest reported in the literature so far. Furthermore, all films showed islandlike surface morphology, regardless of λ.

ELIMINACIÓN BIOLÓGICA DE MEZCLAS DE AMONIO, FENOL, ISÓMEROS DE CRESOL Y SULFURO EN UN REACTOR DE LOTE SECUENCIADO

The kinetic and metabolic ability of a nitrifying sludge to simultaneously oxidize ammonium and mixtures of phenol, p-cresol, m-cresol, o-cresol, and sulfide was evaluated throughout the operation cycles of a sequencing batch reactor (SBR). In the nitrifying SBR, it was possible to remove ammonium (150 mg N/L) by nitrification, mineralize the mixtures of phenolic compounds (up to 120 mg C/L), and oxidize sulfide (15 mg S/L) to sulfate. The addition of mixed phenolic compounds and sulfide into the reactor provoked a decrease in specific rates of the nitrifying processes, however, the use of SBR system allowed a decrease of the inhibitory effects along the cycles. The sludge showed a metabolic adaptation to consume the mixtures of phenolic compounds and sulfide throughout the cycles with increasing specific rates of removal. The obtained results showed that the nitrifying SBR can be used for the treatment of wastewaters contaminated with ammonium, mixtures of phenolic compounds, and sulfide.