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Efficient thin film solar cell technologies, including Cu(In,Ga)(S,Se)2 (CIGS) and CdTe-based cells, have advanced significantly. Yet, environmental concerns and element scarcity fuel the pursuit of alternatives. Copper zinc tin sulfide (Cu(Zn,Sn)(S,Se)2 or CZTS) garners attention for its use of non-toxic, abundant elements. We present a study on CZTS thin film solar cells via low-temperature chemical synthesis. The process involves dissolving Copper (II) acetate, zinc (II) acetate, and tin (II) chloride in 2-methoxyethanol and monoethanolamine to create a metal compound solution. This solution is spin-coated onto molybdenum-coated glass substrates and annealed at 300 °C. The CZTS layer is sulfurized at 400 °C using di-tert-butyl-disulfide (TBDS). Characterization utilized diverse techniques. Scanning electron microscopy (SEM) revealed smoother surfaces post-sulfurization. Optimized compositions, Cu-poor and Zn-rich, vital for enhanced efficiency, were confirmed through energy-dispersive X-ray spectroscopy (EDX). X-ray diffraction (XRD) patterns aligned well with the kesterite phase, with additional phases like ZnS, SnS, SnS2, and CuS detected. X-ray photoelectron spectroscopy (XPS) offered insights into composition and surface contamination. High-resolution scans provided binding energies, validating the film's composition. This study enhances the comprehension and realization of CZTS thin film solar cells, offering a potential avenue for earth-abundant, efficient photovoltaics.

Sulfur, an abundant component of crude oil, causes severe damage to the environment, poses risks to human health, and poisons the catalysts used in combustion engines. Hydrodesulfurization, the conventionally used method, is not sufficient to remove thiophenes like dibenzothiophene (DBT) and other aromatic heterocyclic compounds. The push for “ultra-clean” fuels, with sulfur content less than 15 ppm, drives the need for deep desulfurization. Thus, in conjunction with hydrodesulfurization, efficient and eco-friendly methods of deep desulfurization, like biodesulfurization, are desirable. In biodesulfurization, naturally desulfurizing microorganisms are used, with genetic engineering and biotechnology, to reduce the sulfur content of crude oil to below 15 ppm. In this review, we describe genetic and metabolic engineering approaches reported to date to develop more efficient methods to carry out biodesulfurization, making it a practically applicable reality.

ABSTRACT The hydrogen sulfide (H2S) present in biogas needs to be removed due to concerns about corrosion during transportation, storage, health and safety. One of the existing removal processes is biological, using a biotrickling filter (BTF). In this study, the performance of full-scale BTF for H2S removal under different operating conditions was evaluated. The BTF system was operated for 300 days, during which two spraying regimes (constant and intermittent) and two sources of nitrate (NO3-) as nutrient solution were evaluated (residual effluent from pig farming and synthetic solution prepared with commercial NaNO3). The performance was monitored by the following parameters: removal efficiency (RE), elimination capacity (EC), pH, dissolved oxygen (DO), empty bed residence time (EBRT) and nitrate concentration (NO3-). The results showed an REH2S = 36.3% with an EC= 1.95 gH2S m-3 d-1 for constant spraying, RE= 99.59% and EC= 4.2 gH2S m-3 d-1 for intermittent spraying with residual effluent from pig farming and RE=99.26% and EC= 4.13 gH2S m-3 d-1 with synthetic solution prepared with commercial NaNO3 solution. The results indicate that intermittent spraying provides better efficiency in the removal of H2S from biogas regardless of the nitrate source (effluent or synthetic medium).

Purposes The bimetallic modified Y zeolite is of great importance for the deep removal of thiophene in coking benzene. The influence of metal ion-exchange sequence on the desulfurization performance of zeolite is crucial. Methods A series of bimetallic modified sorbents were prepared by ion-exchange with Cu and Ce. The desulfurization performance of sorbents in thiophene-benzene solutions was evaluated by static adsorption experiments. The physical and chemical properties of sorbents were analyzed by XRD, Py-FTIR, XPS, H2-TPR, and N2 adsorption and desorption techniques. Findings The results show that metal ion-exchange sequence affects the relative crystallinity, ion-exchange degree, metal content, and L acid amount of sorbent. The correlations between the physical, chemical properties and the desulfurization performance of sorbent indicate that the higher the ion-exchange degree, the higher the desulfurization efficiency of sorbent. Meanwhile, the more Cu＋ and Ce4＋ in the sorbent, the more L acid sites formed and the higher its desulfurization efficiency. When Y zeolite is exchanged by Ce first and then Cu, the metal Ce affects the location of Cu and improves reduction performance of Cu. The desulfurization efficiency order of sorbents is CuCeY>CeCuY>Cu-CeY. The desulfurization efficiency of CuCeY is the highest, reaching 97.3%, and its relative crystallinity is the highest and ion-exchange degree is the largest. This work serves as a guide for the preparation of high efficiency desulfurization sorbents.

Abstract A static batch arrangement composed of anti-leak vials coupled to gas chromatography is proposed as a complementary system for performance assessment of biogas desulfurization by adsorption. For testing, a modified commercial activated carbon produced by controlled thermal treatment in the presence of iron(III) species improved biogas desulfurization. The adsorbents showed a superior hydrogen sulfide removal compared to ordinary one. Pseudo-first-order, pseudo-second-order, and Bangham’s kinetic models were used to fit experimental data. All studied samples followed pseudo-first-order model, indicating the predominance of physisorption, and Bangham’s model, confirming that the micropores structure played an important role for gases diffusion and adsorbent capacity. Additionally, the materials were characterized by N2 adsorption–desorption, X-ray diffraction, infrared spectroscopy, scanning electron microscopy and energy-dispersive spectroscopy. The thermal treatment associated with iron impregnation caused significant modifications in the surface of the materials, and the iron species showed two main benefits: an expressive increase in the specific area and the formation of specific adsorption sites for hydrogen sulfide removal. The results reinforce the advantages of iron-modified adsorbents in relation to their non-modified counterparts. The analytical methodology based on the confinement of multiple gases contributes to improving the understanding of the hydrogen sulfide adsorption process using pressure swing adsorption technology. Graphical Abstract

A few-layered hexagonal boron nitride nanosheets stabilized platinum nanoparticles (Pt/h-BNNS) is engineered for oxidation-promoted adsorptive desulfurization (OPADS) of fuel oil. It was found that the few-layered structure and the defective sites of h-BNNS not only are beneficial to the stabilization of Pt NPs but also favor the adsorption of aromatic sulfides. By employing Pt/h-BNNS with a Pt loading amount of 1.19 wt% as the active adsorbent and air as an oxidant, a 98.0% sulfur removal over dibenzothiophene (DBT) is achieved along with a total conversion of the DBT to the corresponding sulfones (DBTO2). Detailed experiments show that the excellent desulfurization activity originates from the few-layered structure of h-BNNS and the high catalytic activity of Pt NPs. In addition, the OPADS system with Pt/h-BNNS as the active adsorbent shows remarkable stability in desulfurization performance with the existence of different interferents such as olefin, and aromatic hydrocarbons. Besides, the Pt/h-BNNS can be recycled 12 times without a significant decrease in desulfurization performance. Also, a process flow diagram is proposed for deep desulfurization of fuel oil and recovery of high value-added products, which would promote the industrial application of such OPADS strategy.

The document discusses the importance of designing catalytic desulfurization processes to prepare clean fuels due to the harmful effects of sulfur compounds in fuels on the environment. Various innovative technologies and catalysts are being developed to meet stringent government regulations on sulfur content in transportation fuels. The research highlighted in this special issue showcases diverse approaches to desulfurization, such as enhancing sulfur oxide capture capacity with iron oxide particles on graphene oxide and designing highly efficient nano-catalysts for sulfur removal. These studies contribute to the ongoing efforts to create cleaner and more sustainable fuel options globally. [Extracted from the article]

The geometry of the ladle bottom and the position of stirring paddles during hot metal stirring significantly influence hydrodynamic characteristics, thereby affecting desulfurization efficiency. Water model experiments and hydrodynamic simulations were conducted to investigate the effects of ladle structures and stirrer positions on the flow field and mixing characteristics in hot metal desulfurization. The results indicate that ladles with a spherical-bottom structure effectively reduced the “dead zone” volume in the hot metal flow. In the water model tests, the mixing time for the spherical-bottom ladle was reduced by 22.5% and 20% at different stirring paddle speeds compared to the flat-bottom ladle, facilitating the better dispersion of the desulfurization agents. The hot metal flow velocities in all directions were also superior in spherical-bottom ladles. Under identical conditions, eccentric stirring generated shallower and broader vortices, with the vortex center offset from the stirring shaft axis, thereby minimizing the risk of “air entrainment” associated with high-speed central stirring. During eccentric stirring, the flow-field distribution was uneven, and the polarization of the stirrer was observed in the water model, whereas central stirring revealed a more uniform and stable flow field, reducing the risk of paddle wear and ladle wall erosion. Central stirring exhibits distinct advantages in the desulfurization process, whereas eccentric stirring is exclusively applicable to metallurgical modes requiring a rapid enhancement of bottom flow and localized rapid dispersion of desulfurizing agents.

In quest of a substantial reduction in potentially toxic gas emissions into the air from industrial plants, dry flue gas desulfurization (FGD) systems offer several advantages, such as reduced operational costs, adaptability, ease of use, and the elimination of liquid waste. This study describes the development of a laboratory-scale pilot system for conducting SO2 abatement experiments using a fixed-bed reactor. To validate the experimental setup, the reactor was equipped with a control system for measuring and monitoring relative humidity, temperature, and total flux composition. The study utilized two standards, slaked lime and 13X zeolite, under identical experimental conditions to ensure comparability. This research will significantly advance the understanding of adsorbent materials for capturing low SO2 concentrations by measuring adsorption kinetics and equilibrium data. The findings highlight the impact of distinct morphological, chemical, and crystallographic properties on the efficiency of dry FGD systems.

Two-dimensional (2D) metal monochalcogenides have recently attracted significant interest following the extensive and intensive research into transition metal dichalcogenides (TMDs). However, the formation of transition metal monochalcogenide remains relatively unstudied. Here, we investigate the structural and electronic changes of the MoS2 monolayer by removing the top sulfur layer using low-energy He+ ion sputtering. As a result, the substoichiometric MoSx surface induces semiconducting to the metallic phase transition. Under ambient conditions, the oxidized MoSx surface restores a semiconducting state with narrowed bandgap, p-type conduction, or possibly a semimetallic state. Our findings provide an effective way to form and improve the functionality of Janus TMD monolayers. [ABSTRACT FROM AUTHOR]

An effective one‐pot approach has been devised for the selective synthesis of alkynyl sulfides through the cleavage of C−S bonds in alkynyl sulfonium salts. This method involves a base‐promoted nucleophilic ring‐opening and desulfurization pathway, enabling the efficient preparation of diverse alkynyl sulfide compounds. The reaction demonstrates excellent tolerance to various functional groups and proves applicable to the late‐stage functionalization of bioactive molecules and pharmaceuticals. Moreover, the practicality of this method has been underscored through scale‐up reaction and modification of alkynyl sulfide products. [ABSTRACT FROM AUTHOR]

The study of catalysts supported by polyoxometalates (POMs) with green oxidative desulfurization activity is an important research topic in oil refining. In this paper, a nano-sized H-β zeolite support was modified by tetraethyl orthosilicate (TEOS) and tetrabutyl titanate (TBOT) to form a microporous–mesoporous structure. On this basis, the modified H-β zeolite was used as a support to load POMs with different structures. The characterization results of Fourier transform infrared (FT-IR) spectroscopy, X-ray powder diffraction (XRD), ultraviolet-visible (UV-vis) diffuse reflectance spectroscopy, scanning electron microscopy (SEM), N2 adsorption–desorption, X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy showed that POMs had been successfully loaded onto the support, and the skeleton structures of POMs and zeolites were maintained. The introduction of POMs significantly improved the ODS performance of bulky organic sulfides, especially benzothiophene (BT). The order of catalytic oxidative desulfurization activity of POMs with different structures was: Keggin > Sandwich ≈ Anderson > monovacant Dawson > Dawson > MoO3. Under the optimum reaction conditions: T = 50 °C, t = 1 h, moil : mcatalyst = 35 : 1, and n(O) : n(S) = 13 : 1, the oxidation conversion of BT and dibenzothiophene over the catalyst supported by phosphotungstic acid (HPW) reached 99.9%. The role of titanium active species, peroxide polyoxometalate, and titanium–silicon composite oxides in improving the oxidative removal of organic sulfides was discussed. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel type of PILs has been fabricated. • PILs integrate the permanent pores of porous solids with the exceptional properties of ILs. • PILs possess high activity and selectivity for the DBT oxidation. • IL moiety serves as an extractant to enrich DBT and creates an electrostatic solvent effect. • UiO-66 moiety serves as a catalysis to handily catalyze the ODS reaction. Developing a highly efficient strategy for the stabilization of the solid-liquid interface is a persistent pursuit for researchers. Herein, porous ionic liquids based on UiO-66 (Zr) porous materials were synthesized and applied to the selective desulfurization catalysis, which integrates the permanent pores of porous solids with the exceptional properties of ionic liquids. Results show that porous ionic liquids possess high activity and selectivity for dibenzothiophene. Experimental analysis and density functional theory calculations revealed that the ionic liquids moiety served as an extractant to enrich dibenzothiophene into the porous ionic liquids phase through the π···π and C H···π interactions. Additionally, the electrostatic solvent effect in the porous ionic liquids contributes to the stabilization solid-liquid interface, which was favorable for UiO-66 moiety to catalytically activate hydrogen peroxide (H 2 O 2) to generate ·OH radicals, and subsequently oxidized dibenzothiophene to the corresponding sulfone. It is hoped that the development of porous ionic liquids could pave a new route to the stabilization of the solid-liquid interface for catalytic oxidation. [ABSTRACT FROM AUTHOR]

Porous Ionic Liquids (PILs) have gained attention but facing challenges in catalysis, especially in liquid‐liquid two‐phase reactions due to limited catalytic sites and hydrophilicity control. This work engineered a Type III PILs (PILS‐M) using zeolitic imidazolate framework‐8 (ZIF‐8) confined phosphomolybdic acid (HPMo) as the microporous framework and N‐butyl pyridine bis(trifluoromethane sulfonyl) imide ionic liquid ([Bpy][NTf2]) as the solvent. The PILS‐M not only combines the advantages of traditional ionic liquids and microporous frameworks, including excellent extraction, high dispersion of catalytically active species, remarkable stability, etc., but also can make the inner surface of ZIF‐8 turned to be hydrophilic that favors the contact between aqueous hydrogen peroxide oxidant and catalytically active sites for the promotion of catalytic performance in reactive extractive desulfurization (REDS) processes of fuel oils. This study demonstrates Type III PILs' potential as catalysts for sustainable chemical processes, offering insights into versatile PILs applications in diverse fields. [ABSTRACT FROM AUTHOR]

In recent years, dibenzyl disulfide (DBDS) in transformer oils has caused many transformer failures around the world, and its removal has attracted more attention. In this work, nine imidazolium-based ionic liquids (ILs) were applied as effective, green desulfurization extractants for DBDS-containing transformer oil for the first time. The results show that the desulfurization ability of the ILs for DBDS followed the order of [BMIM]FeCl4 > [BMIM]N(CN)2 > [BMIM]SCN > [BMIM](C4H9O)2PO2 > [BMIM]MeSO4 > [BMIM]NTf2 > [BMIM]OTf > [BMIM]PF6 > [BMIM]BF4. Especially, [BMIM]FeCl4 ionic liquid had excellent removal efficiency for DBDS, with its S partition coefficient KN (S) being up to 2642, which was much higher than the other eight imidazolium-based ILs. Moreover, the extractive performance of [BMIM]FeCl4 increased with an increasing molar ratio of FeCl3 to [BMIM]Cl, which was attributed to its Lewis acidity and fluidity. [BMIM]FeCl4 ionic liquid could also avail in the desulfurization of diphenyl sulfide (DPS) from model oils. The experimental results demonstrate that π−π action, π-complexation, and Lewis acid−base interaction played important roles in the desulfurization process. Finally, the ([BMIM]FeCl4) ionic liquid could be recycled five times without a significant decrease in extractive ability. [ABSTRACT FROM AUTHOR]

In this study, Erdos (ED) high sulfur coal was selected to investigate the sulfur fixation effect of copper oxide (CuO) on H2S, SO2, COS and sulfur-containing radicals formed during pyrolysis by the gas chromatography (Py-GC) and XPS combined with density functional theory (DFT) calculations. By Py-GC analysis, H2S, COS and SO2 release of ED coal significantly decrease after adding 6% CuO, illustrating CuO can adsorb sulfur-containing radicals and prohibit the generation of these three sulfur-containing gases. The adsorption mechanisms of sulfur-containing radicals produced during coal pyrolysis on different CuO surfaces were investigated by DFT calculations. After optimization, the multi-adsorption configurations of ·S·, ·SH and ·S–S· on different CuO (111, O-terminated 110 and Cu-terminated 110) surfaces can be obtained. According to their highest absolute adsorption energies, the O-terminated CuO (110) surface is more favorable for ·S· and ·SH adsorption rather than other two surfaces, while the Cu-terminated CuO (110) surface for the adsorption of ·S–S· and the co-adsorption of ·S·, ·SH and ·S–S· during coal pyrolysis. Furthermore, ·SH is easily dissociated on the O-terminated CuO (110) surface. The S atoms of ·S· and ·SH are bonded with two Cusuf atoms, and every S atom of ·S–S· combines with one Cusuf on the Cu-terminated CuO (110) surface, leading to the generation of two substances similar to Cu2S and sulfide during co-adsorption. This is very consistent with the apparent appearing peak of Cu2S and remaining peak of sulfide in XPS spectra of CuO-ED char. Thus, these DFT theoretical calculations can testify the experimental results of CuO inhibiting H2S, COS and SO2 to release. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Expressed protein ligation (EPL) provides a powerful tool to access large‐size proteins with precise structures. Existing methods for constructing the critical protein thioester for EPL have predominantly relied on the recombinant intein fusion expressed in Escherichia coli (E. coli). Despite its powerful applications, the expression of thioester derived from eukaryotic protein in E. coli inherently suffers from its limited solubility, the inactivity of intein, premature hydrolysis and low yields. To overcome these obstacles, we present herein the facile one‐flask synthesis of inaccessible protein α‐thioester via a SUMO‐protein‐intein (SPI) sandwich model. The utility of SUMO enhances the protein fusion yield and solubility, prevents premature hydrolysis and simplifies the purification process. The inaccessible protein thioester with internal Cys residues can be readily produced and is compatible with the EPL‐desulfurization protocol used to prepare complex proteins, which is otherwise difficult to obtain using traditional methods. Its utility has been highlighted through the synthesis of human granulocyte colony‐stimulating factor (G‐CSF). [ABSTRACT FROM AUTHOR]

Visible‐light assisted a very simple and mild protocol for photocatalytic oxidative transformation of thioamide to amide group has been realized in cyclic system. For this purpose 5‐arylalkylidene‐rhodanine derivatives were chosen as model substrates to afford thiazolidine‐2,4‐diones. Light mediated reactions are intrinsically beneficial, since activation occurs by cleanest energy source light. Here K2S2O8 is used as terminal oxidant which does not leave any hazardous and corrosive waste to discard after the reaction fostering the practices of green chemistry. This is the first report of conversion of thioxo group in rhodanine derivatives into the corresponding oxygen analogue by visible light photo‐catalytic method. The reaction was very general since various 5‐arylalkylidene‐rhodanines underwent the reaction smoothly affording high product yields. Moreover, the broadness of this protocol was further established by applying this reaction on other systems like 3,4‐dihydropyrimidine‐2(1H)‐(thio)ones. [ABSTRACT FROM AUTHOR]

The desulfurization process of fuels is a requirement due to environmental pollution. Different techniques are used in the desulfurization process such as adsorption desulfurization. In this work, aminated chitosan and functionalized carbon nanotube were used to prepare adsorbent nanocomposite and as a model sulfur-containing aromatic compound, dibenzothiophene (DBT) was employed. Fourier transform infrared spectroscopy, scanning electron microscopy and tunneling electron microscopy, and the N2 adsorption–desorption isotherm techniques were used for the characterization of the synthesized nanocomposite. The microscopic images revealed the structure of the adsorbent was mesoporous with a pore diameter of about 21 nm. The desulfurization study was conducted by batch adsorption experiments in various mass-loaded adsorbents, contact time, concentration, and temperatures for thermodynamic and kinetic behavior of adsorbents. The results showed adsorption capacity and removal efficiency of DBT were 36.4 mg/g and 64.1%, respectively. The best-fitted kinetic and isotherm models were obtained to be the pseudo-second-order model and Frendulich model, respectively. Also, by comparing the pristine nanocomposite (pristine chitosan) desulfurization results with functionalized ones, it showed a 20% enhancement in adsorption capacity by an increase in amine group numbers. According to the results of this study, this novel nanocomposite has the potential to be used in the adsorption desulfurization process. [ABSTRACT FROM AUTHOR]

A study was carried out on the quality of the cobalt carbonate raw material and heat treatment conditions on the activity of Co-Mo and Ni-Mo hydrotreating catalysts for a mixed diesel fraction. The relevant properties of the impregnation solution are the purity of the cobalt carbonate starting material and the synthesis temperature. A Raman spectroscopic method was proposed for monitoring the cobalt carbonate quality. Heat treatment of the catalyst was found to affect its activity. The optimal ultimate calcination temperatures for the Co-Mo and Ni-Mo catalysts were found to be very different. [ABSTRACT FROM AUTHOR]

NiMoS/TiMg and NiWS/TiMg nanocatalysts were synthesized, characterized by various techniques and tested in the hydrodesulphurization (HDS) of dibenzothiophene (DBT). TiMg mixed oxides containing 5, 10 or 15 wt% of MgO were prepared by sol–gel and then used as catalyst supports. A constant atomic ratio of Ni/(Ni + M) = 0.5 was kept for all the catalysts (M = Mo or W). The catalysts were first prepared by sequential-wet impregnation. Then, after an ex-situ sulfidation process, they were characterized by high resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD), and physisorption of N2 following the BET method. The presence of MgO in the NiMoS/TiMg and NiWS/TiMg catalysts resulted in an enhancement in the HDS activity of DBT. In addition, their HDS activities were higher than those observed in the NiMoS/Ti and NiWS/Ti catalysts. Furthermore, higher HDS activity was found for the NiMoS/TiMg compared with their NiWS/TiMg catalysts counterpart. [ABSTRACT FROM AUTHOR]

Catalytic oxidative desulfurization (ODS) using titanium silicate catalysts has emerged as an efficient technique for the complete removal of organosulfur compounds from automotive fuels. However, the precise control of highly accessible and stable-framework Ti active sites remains highly challenging. Here we reveal for the first time by using density functional theory calculations that framework hexa-coordinated Ti (TiO6) species of mesoporous titanium silicates are the most active sites for ODS and lead to a lower-energy pathway of ODS. A novel method to achieve highly accessible and homogeneously distributed framework TiO6 active single sites at the mesoporous surface has been developed. Such surface framework TiO6 species exhibit an exceptional ODS performance. A removal of 920 ppm of benzothiophene is achieved at 60°C in 60 min, which is 1.67 times that of the best catalyst reported so far. For bulky molecules such as 4,6-dimethyldibenzothiophene (DMDBT), it takes only 3 min to remove 500 ppm of DMDBT at 60°C with our catalyst, which is five times faster than that with the current best catalyst. Such a catalyst can be easily upscaled and could be used for concrete industrial application in the ODS of bulky organosulfur compounds with minimized energy consumption and high reaction efficiency. [ABSTRACT FROM AUTHOR]

Using a simple acid-base neutralization method, a Ch-PW solid catalyst was synthesized by mixing choline hydroxide (ChOH) and phosphotungstic acid (HPW) at a 2:1 molar ratio in an aqueous solution. This catalyst was combined with a 20 wt.% potassium peroxymonosulfate (PMS) solution, using acetonitrile (ACN) as the extraction solvent to create an extraction catalytic oxidative desulfurization system. The optimal desulfurization conditions were determined through response surface methodology, targeting the highest desulfurization rate: 0.99 g of Ch-PW, 1.07 g of PMS, 2.5 g of extraction solvent, at a temperature of 50.48 °C. The predicted desulfurization rate was 90.79%, compared to an experimental rate of 93.64%, with a deviation of 3.04%. A quadratic model correlating the desulfurization rate with the four conditions was developed and validated using ANOVA, which also quantified the impact of each factor on the desulfurization rate: PMS > ACN > Ch-PW > temperature. GC-MS analysis identified the main oxidation product as DBTO2, and the mechanism of desulfurization in this system was further explored. [ABSTRACT FROM AUTHOR]

A binuclear dioxomolybdenum catalyst [(MoO2Cl2)2(L)] (1) (with L (1S,2S)-N,N′-bis(2-pyridinecarboxamide)-1,2-cyclohexane) was prepared and used as catalyst for the desulfurization of a multicomponent model fuel containing the most refractory sulfur compounds in real fuels. This complex was shown to have a high efficiency to oxidize the aromatic benzothiophene derivative compounds present in fuels, mainly using a biphasic 1:1 model fuel/MeOH system. This process conciliates catalytic oxidative and extractive desulfurization, resulting in the oxidation of the sulfur compounds in the polar organic solvent. The oxidative catalytic performance of (1) was shown to be influenced by the presence of water in the system. Using 50% aq. H2O2, it was possible to reuse the catalyst and the extraction solvent, MeOH, during ten consecutive cycles without loss of desulfurization efficiency. [ABSTRACT FROM AUTHOR]

TiO2-Al2O3 supports with different incorporation methods of titania were synthesized via three methods: impregnation (TA-I), co-precipitation (TA-CP), and co-precipitation–hydrothermal treatment (TA-HT). And the NiMoP catalysts prepared on the corresponding supports were evaluated for hydrodesulfurization (HDS) reactions. The results demonstrated that the Ti atoms in TA-I are attached to alumina through hydroxyl groups, while the Ti atoms in TA-CP and TA-HT can be dispersed in the alumina skeleton. Variations in the incorporation modes of TiO2 affect the support properties, consequently influencing the nature of the active metal on the supports. The Ti atoms dispersed in the Al2O3 skeleton allow an increase in the basic hydroxyl groups. Meanwhile, TiO2 in TA-CP and TA-HT can absorb hydrogen molecules and be partially reduced. Furthermore, metal species supported on the TA-CP and TA-HT are more easily reduced and better dispersed. For the NiMoP catalysts prepared with TA-CP and TA-HT, the Ti element promotes the sulfidation degree of Mo, besides shortening the average (Ni)MoS2 slab. The catalysts prepared with TA-CP exhibited superior activity for 4,6-DMDBT hydrodesulfurization. This can be ascribed not only to the relatively high sulfidation degree of Mo and proportion of the NiMoS active phase but also to the well-dispersed (Ni)MoS2 slabs. Moreover, the Ti4+ ions dispersed in the Al2O3 skeleton can be partially reduced to act as electron donors, enhancing the metallic character of the S layers in MoS2, which facilitates the improvement of the hydrogenation desulfurization activity. [ABSTRACT FROM AUTHOR]

To effectively reduce SO2 emissions, flue gas desulfurization methods are widely used in coal‐fired power plants. In desulfurization, the dry sorbent injection (DSI) technology has the advantages of high desulfurization efficiency, simple operation, convenient adjustment, and low initial investment. Here, a pilot‐scale experimental system was designed and built to investigate the desulfurization characteristics of the DSI technology. The influence of the residence time of the desulfurizer, the reaction temperature, the stoichiometric ratio of the desulfurization reaction, the particle size of the desulfurizer, the inlet SO2 concentration, the dust concentration, and the water vapor content in the flue gas on the desulfurization efficiency at low SO2 concentrations was studied by injecting NaHCO3 into the pipeline. The desulfurization efficiency can be significantly improved by reducing the desulfurizer particle size or increasing the water vapor content in the flue gas at low SO2 concentration. An empirical formula describing the dependence of the desulfurization efficiency on experimental parameters is given. [ABSTRACT FROM AUTHOR]

It is crucial for recycling scrap steel to effectively remove impurities such as sulfur and oxygen, which directly determine the characteristics of inclusions in steel liquid. This study attempts to investigate the effect of Al concentration on the cleanliness of x% Al–7CrSiMnMoV steel by directly smelting scrap steel. Impurities such as sulfur and oxygen, as well as alloying elements in steel, are investigated. Also, the evolution characteristics of inclusion in the x% Al–7CrSiMnMoV steel are evaluated. The results show that the oxygen concentration in steel liquid gradually decreases; however, the sulfur concentration in steel liquid first increases and then decreases as the aluminum concentration increases from 0.026% to 0.58%. A high‐cleanliness 0.58% Al–7CrSiMnMoV steel with sulfur and oxygen concentrations of 0.0015% and 0.0018%, respectively, can be obtained. Additionally, the high Al–Ca–Mg–O and high Ca–Al–Mg–O contain S composite inclusions, and a small amount of fine Mn(Ca)S inclusions first form the high‐Al–Ca–Mg–O composite inclusions with an aluminum concentration of 0.026%, then form the high‐Al–Mg–O, Al–Mg–O‐wrapped Mn(Ca)S, and a large number of fine MnS inclusions with an aluminum concentration of 0.11%; eventually, it forms Al–Mg–O‐wrapped CaS as the Al concentrations continuously increase. [ABSTRACT FROM AUTHOR]

Steel quality, to a large extent, is controlled by ladle refining reactions. The understanding of such reactions can help to prevent the formation of unwanted phases and improve the overall high‐temperature process control. A new approach, namely, the multioxide inclusion kinetic model has been recently developed to simulate steel–inclusion reactions in liquid steel. The coupling of this kinetic model with a multicomponent, multiphase steel–slag reaction interface model leads to an overall model framework to predict the evolution of steel, slag, and inclusion composition. The current work shows the application of the model to simultaneous deoxidation and desulphurization during ladle refining of Si–Mn‐killed steel. The model shows good performance with industrial data. It is demonstrated that for ladle refining practices, silica‐rich slags should be strictly used with basicity (CaO/SiO2) between 1 and 1.2 and with Al2O3 content less than 5 wt%. Additional simulations are also carried out to reveal the capability of the model to aid in online process control. Finally, certain limitations of the current model are discussed. [ABSTRACT FROM AUTHOR]

A new method for the preparation of hydrodesulfurization catalysts based on the mechanochemical treatment of molybdenum under cryogenic conditions was proposed. The results of direct one-stage mechanochemical grinding of molybdenum at 77 K in gaseous media of He and H2 and in liquid N2, as well as in the presence of solid Ar, are reported. The physicochemical properties of the cryopowders and their catalytic activity in the model hydrodesulfurization reactions of dibenzothiophene and diesel fraction were examined. [ABSTRACT FROM AUTHOR]

The Feixianguan gas reservoir in northeast Sichuan is a high to ultra-high sulfur content reservoir. Based on the analyses of the geology of the Feixianguan formation and the difficulties in drilling fluid operation, a desulfurization measure is presented for field operation with oil based drilling fluids. High performance desulphurizing agents are first selected through laboratory experiment, and studies on the compounding of these agents are conducted to develop a compound desulphurizing agent. Evaluation of the performance of the compound desulphurizing agent to remove sulfur at elevated temperatures shows that the compound desulphurizing agent containing 3%YT-3+3%CLC-2 and 3%JD-2 has percent H2S prevention of 99.14% and percent H2S removal of 100%. The zinc-based desulfurizing agent in the formula reacted with H2S in the drilling fluids to produce insoluble chemical ZnS. The triazine and alcohol ether amide desulfurizing agents mainly remove H2S through fast and irreversible physical and chemical reactions. This desulfurization technology has been successfully applied on the well Po-005-X4 and the well Po-002-H5 when drilled into the high sulfur content Feixianguan formation, no H2S has been detected during drilling and during circulation after tripping for degassing, and the S2− content of the drilling fluid is zero throughout the whole drilling operation. The successful field operation fully demonstrates that the technology has a significant desulfurization performance and can meet the requirements of drilling high sulfur wells. [ABSTRACT FROM AUTHOR]

A machine learning model was developed to predict the desulfurization process during the Kanbara reactor hot metal treatment. Compared with other algorithms, the LR algorithm model exhibited the smallest error in current calculations, which was used to predict the final S content with various operation parameters. The final S content in the hot metal obviously rose from 0.001% to higher than 0.003% with the increase of the initial S content from 0.03% to 0.06%, while it decreased from 0.003% to below 0.001% with the increase from desulfurizer addition from 4 kg/ton to 7 kg/ton. The final S content changed little with the increase of C content, Mn content, and rotation speed. The feature selection using RReliefF algorithm was conducted to evaluate the correlation between inputted parameters and outputted final S content. The addition of desulfurizers was beneficial to improve the desulfurization efficiency, while it obviously increased desulfurization costs. The longer desulfurization time lowered the S content, while it resulted in higher desulfurization costs due to the refractory erosion and electric power consumption. [ABSTRACT FROM AUTHOR]

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The quality of bauxite resources in China is deteriorating, and the high-grade bauxite resources are depleting day by day, the resource problem has become an important problem for the development of China's aluminum industry, and the high sulfur and high iron bauxite, which has not yet been exploded on an industrial scale, belongs to the difficult-to-use resources, and it has a huge potential industrial value, and it is of great theoretical and practical significance to carry out the basic research on desulfurization and removal of iron from high sulfur and high Hon bauxite. For the comprehensive development and utilization of high sulfur and high iron bauxite in Guangxi, a systematic test of desulfurization and Hon removal from bauxite was carried out by using the process of "suspension oxidation roasting-reduction roasting-magnetic separation", and the transformation of mineral phases in the roasting process was studied by using the methods of X-ray diffraction analysis (XRD), chemical phase analysis, and X-ray photoelectron spectroscopy (XPS), etc. The test was carried out on the basis of "suspension oxidation roasting-reduction roasting-magnetic separation" . The results showed that the main sulfur containing and iron-containing mineral is pyrite, the process of "suspension oxidation roasting-reduction roasting-magnetic separation" can simultaneously realize the efficient removal of sulfur and the enrichment and separation of Hon. Under the conditions of suspension oxidation roasting with roasting temperature 700 °C, roasting time 40 min, O2 concentration 40%, and the total gas volume 600 mL/min, an oxidized roasting product with S, of 0.396% and desulfurization rate of 98.10% can be obtained. Suspension reduction roasting was then carried out under the conditions of roasting temperature 550 °C, roasting time 20 min, CO concentration 20%, total gas volume 600 mL/min, and magnetic Held strength 150 kA/m, which resulted in an iron ore concentrate with TFe grade of 54.79% and aluminum-rich ore with St of 0.248%, TFe grade of 4.37% and Al2O3 content of 75.27%. This technology substantially increases the Al2O3 content of high sulfur high iron bauxite, which is conductive to the subsequent dissolution of bauxite and achieves the technical goal of desulfurization and removal of iron to raise aluminum content. This process provides a new technical way for the efficient utilization of this kind of difficult--to-process to select high sulfur high iron bauxite resources. [ABSTRACT FROM AUTHOR]

Aluminum is an important metal material in people's modern life, and bauxite is the main raw material for the production of aluminum. With the continuous development of domestic aluminum industry, the demand for bauxite resources is increasing year by year. However, the quality of domestic bauxite resources is poor, the supply is insufficient, and the degree of external dependence of bauxite is high, which brings a serious threat to the supply security of aluminum resources in China and restricts the sustainable development of China's aluminum industry. In order to cope with the scarcity of high-quality bauxite resources in China, the development of complex and difficult-to-process bauxite resources, such as high sulfur and high iron bauxite, is crucial to ensuring the strategic security of China's bauxite resources. China has a large amount of complex bauxite resources, such as high-sulfur and high-iron bauxite, which is more than 1.5 billion tons, accompanied by other strategic metal resources, which is urgently needed to be efficiently developed and advanced technology is used to realize the industrial application of this kind of typical poor and miscellaneous bauxite. Excessive sulfur and iron impurities in bauxite will have non-negligible effects on the process of aluminum extraction by Bayer process, such as corroding equipment and pipes, increasing alkali consumption and red mud, affecting the quality of alumina and so on. Therefore, starting with the present situation and characteristics of high-sulfur and high-iron bauxite resources in China, the current research progress of desulphurization and iron removal process of high-sulfur and high-iron bauxite has been summarized. The main desulfurization technologies such as flotation desulfurization, perorating desulfurization, biological desulfurization and physical iron removal, chemical iron removal and biological iron removal are summarized. The industrial application level of various processes is discussed and several typical examples of industrial application of high-sulfur and high-iron bauxite are given. It will provide theoretical support for the development and utilization of complex bauxite resources in China, make effective use of difficult-to-process aluminum resources, reduce China's dependence on foreign aluminum resources, and improve the supporting force of bauxite resources. [ABSTRACT FROM AUTHOR]

Dense-phase-tower desulfurization technology is an emerging semi-dry flue-gas desulfurization ash process, i.e., the flue gas is allowed to enter the desulfurization tower from the bottom up and, at the same time, is sprayed with a desulfurizing agent that undergoes an acid–base reaction with the flue gas in the ascent process. The calcium sulfite and calcium sulfate produced by the reaction and the part of the desulfurization agent that is not involved in the reaction will enter the subsequent dust removal system, and what is retained is the by-product desulfurization ash. This desulfurization ash contains a large amount of calcium sulfite, which leads to its unstable nature; it is easily oxidized and expands in volume, and, if used in the field of building materials, it will lead to cracking and other problems, so it is difficult to effectively use it. In order to solve this problem, XRF, XRD, and iodometric and other analytical methods were used to determine the specific composition of desulfurization ash, and the muffle furnace and vertical tube furnace were used to study the thermal oxidative modification of calcium sulfite in desulfurization ash, to investigate the effects of the oxygen content, reaction temperature, medium flow rate, and chloride content on the oxidation of calcium sulfite, and to analyze the thermodynamics in the high-temperature oxidation reaction. The results showed that the oxidation rate of calcium sulfite increased with higher reaction temperatures. Increased oxygen content promoted the oxidation rate, particularly at low oxygen levels. The oxidation rate of calcium sulfite correlated positively with the medium flow rate until a rate of 75 mL·min− was reached. At a reaction temperature of 420 °C and a gas flow rate of 85 mL·min−1, the oxidation conversion efficiency exceeded 89%. Chloride content significantly reduced the oxidation rate of calcium sulfite, although this inhibition weakened at temperatures above 500 °C. Kinetic analysis suggested that the oxidation reaction of calcium sulfite predominantly occurred below 500 °C. These findings have both theoretical and practical implications for the thermal oxidation treatment and disposal of desulfurization ash. [ABSTRACT FROM AUTHOR]

KR (Kanbara Reaction) desulfurization slag is a solid waste that is not sufficiently utilized. This is because the KR desulfurization slag contains 1–2.5% sulfur, which is directly used in steel smelting to increase the sulfur content in molten steel. Therefore, the possibility of oxidation desulfurization of KR desulfurization slag was studied in this study. Experiments were conducted to investigate the possibility of removing sulfur from used KR (Kambara Reaction) slag with oxidation. The KR slag samples were treated with oxidative desulfurization in the oxygen partial pressure range of 0.05 bar–1.00 bar, with a gas flow rate ranging from 2 L min−1 to 6 L min−1, and at a temperature of 1420 °C. X-ray diffraction (XRD), an infrared carbon sulfur analyzer, and scanning electron microscopy–energy dispersive X-ray spectrometry (SEM–EDS) analysis were used to reveal the oxidative desulfurization mechanism of KR desulfurization slag. At low oxygen pressure ( P O 2 < 0.20 bar), the desulfurization rate of slag oxidized for 120 min increased with the increase in oxygen partial pressure. At high oxygen pressure ( P O 2 ≥ 0.20 bar), the desulfurization rate of slag samples did not change with the change in oxygen partial pressure, and the desulfurization rate was higher than 93.5%. At low oxygen pressure ( P O 2 < 0.20 bar), the residual sulfur in the slag after oxidation still existed in the slag as the CaS phase. At high oxygen pressure ( P O 2 ≥ 0.20 bar), the residual sulfur in the slag oxidized from the CaS phase to the 11CaO·7Al2O3·CaS phase in the slag. The sulfur removal rate was directly correlated with the slag surface area and the flow rate of the reaction gas, and it increased with an increase in both surface area and gas flow rate. [ABSTRACT FROM AUTHOR]

Red gypsum (RG) is an industrial waste generated from the titanium dioxide process produced. For the low-cost and high-benefit utilization of RG, calcium sulfate (CaS) was prepared from recycled RG. Rod-like gypsum crystals with a rough surface, uniform size, 1 µm in diameter and 5 µm in length, were obtained, when the as-prepared CaS was divided into three equal portions and one portion was added at each interval of 2 h to neutralize the simulated acidic wastewater. CaS was prepared from RG to neutralize acidic wastewater to produce silicon-enriched RG for the next cycle. High silica residue (HSR) was obtained after 6 cycles. The effect of calcined temperature on the desulfurization of HSR was investigated. The sulfur content in the residue decreased by 97% after calcined at 1200 ℃ for 2 h. According to GB/T 12957-2005 "Industrial waste residue activity test method for cement admixture", the activity index of desulfurized HSR was 90%, which it can be used as a cementing material. [ABSTRACT FROM AUTHOR]

Preparation technology and functional modification research progress of nonwoven air filter materials were summarized. Preparation methods of nonwoven air filter material were described, including needle punching, meltblown and electrospinning. The problems existed in different nonwoven technology were analyzed. The functional modification of nonwoven air filter materials were discussed, such as antibacterial, formaldehyde removal, denitrification, desulfurization and high temperature resistance. It is considered that the future development direction is to prepare green and high-efficiency nonwoven air filtration materials by optimizing the technology flow and adjusting the fabric structure. [ABSTRACT FROM AUTHOR]

In recent years, due to the rapid growth of mankind's demand for energy, harmful gases (SOx) produced by the combustion of sulfur-containing compounds in fuel oil have caused serious problems to the ecological environment and human health. Therefore, in order to solve this hidden danger from the source, countries around the world have created increasingly strict standards for the sulfur content in fuel. Adsorption desulfurization technology has attracted wide attention due to its advantages of energy saving and low operating cost. This paper reviewed the latest research progress on various porous adsorption materials. The future challenges and research directions of adsorption materials to meet the needs of clean fuels are proposed. [ABSTRACT FROM AUTHOR]

A static batch arrangement composed of anti-leak vials coupled to gas chromatography is proposed as a complementary system for performance assessment of biogas desulfurization by adsorption. For testing, a modified commercial activated carbon produced by controlled thermal treatment in the presence of iron(III) species improved biogas desulfurization. The adsorbents showed a superior hydrogen sulfide removal compared to ordinary one. Pseudo-first-order, pseudo-second-order, and Bangham's kinetic models were used to fit experimental data. All studied samples followed pseudo-first-order model, indicating the predominance of physisorption, and Bangham's model, confirming that the micropores structure played an important role for gases diffusion and adsorbent capacity. Additionally, the materials were characterized by N2 adsorption–desorption, X-ray diffraction, infrared spectroscopy, scanning electron microscopy and energy-dispersive spectroscopy. The thermal treatment associated with iron impregnation caused significant modifications in the surface of the materials, and the iron species showed two main benefits: an expressive increase in the specific area and the formation of specific adsorption sites for hydrogen sulfide removal. The results reinforce the advantages of iron-modified adsorbents in relation to their non-modified counterparts. The analytical methodology based on the confinement of multiple gases contributes to improving the understanding of the hydrogen sulfide adsorption process using pressure swing adsorption technology. [ABSTRACT FROM AUTHOR]

In order to improve the oxidative desulfurization (ODS) performance of MOF materials, an effective way is to convert a microporous MOF into a hierarchical porous MOF (HP-MOF) by utilizing the linker selective retention strategy. Herein, UiO-66 with the introduction of an unstable linker ligand (dihydro-1,2,4,5-tetrazine-3,6-dicarboxylate, dhtz) can selectively remove dhtz ligands to form HP-MOF (HP-UiO-66-dhtz) through heat treatment at high temperature. While maintaining the original structure of UiO-66, HP-UiO-66-dhtz features mesopores and abundant Lewis acid sites, showing excellent ODS performance for diphenylthiophene (DBT). [ABSTRACT FROM AUTHOR]

HKUST-1 is a well-known copper-based metal-organic framework (MOF), promising to be used in separation processes, however its industrial usage remains confined due to its difficult handling and low mechanical stability when in powder form. In this work, we have synthesized and analyzed the mechanical properties of novel HKUST-1 shaped composites based on methylcellulose (MC) and poly(vinyl formal) (PVMF), using a simple and inexpensive extrusion technique. The composites were characterized using different techniques, such as Fourier transform infrared (FTIR) spectroscopy and powder X-ray diffraction (PXRD) analysis, which demonstrated that their structure and crystallinity were not compromised by the shaping process. Their mechanical properties were investigated by compressive strength measurements and scanning electron microscopy (SEM). The composite with methyl cellulose showed good mechanical resistance, with an average crushing strength value of 40 N. Nitrogen sorption measurements showed that the specific surface area reduction due to the shaping process for HKUST@MC was only 8.6%. The greater hydrolytic stability after heat activation of HKUST@MC compared to that of the pure MOF was also verified. The adsorptive capacity of HKUST@MC towards organosulfur compounds found in sour gas was evaluated in a desulfurization test using a realistic multicomponent gas mixture. HKUST@MC exhibiting a high efficiency to adsorb organosulfur outperformed the benchmark sulfur adsorbent Norit RGM 3 in the adsorption of ethanethiol and dimethyl disulfide. Therefore, in this work we present a technically feasible and cost-effective method to produce a novel HKUST-1 shaped composite with good mechanical and water resistance properties preserving the MOF porosity and gas adsorption properties. [ABSTRACT FROM AUTHOR]

A highly efficient oxidative desulfurization composite catalyst NH2‐Uio‐66‐Mo has been prepared and applied in the catalytic oxidative desulfurization. It was elucidated that Mo6+ could increase the oxygen vacancies and active sites on the catalyst and increase the pore size of UiO‐66. Meanwhile, the removal rate of dibenzothiophene (DBT) reached 99.2 % after 60 min under optimal conditions and remained above 90 % after 5 cycles, showing the composite catalyst's remarkable catalytic performance and satisfactory reusability NH2‐UiO‐66‐Mo. In addition, kinetic studies revealed that the desulfurization process can present a pseudo‐first‐order kinetic process. The apparent activation energy was 10.6 kJ/mol. Finally, in combination with oxides, possible oxidation pathways were identified. [ABSTRACT FROM AUTHOR]