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Methods enabling the dechalcogenation of thiols or selenols have been investigated and developed for a long time in fields of research as diverse as the study of prebiotic chemistry, the engineering of fuel processing techniques, the study of biomolecule structures and function or the chemical synthesis of biomolecules. The dechalcogenation of thiol or selenol amino acids is nowadays a particularly flourishing area of research for being a pillar of modern chemical protein synthesis, when used in combination with thiol or selenol-based chemoselective peptide ligation chemistries. This review offers a comprehensive and scholarly overview of the field, emphasizing emerging trends and providing a detailed and critical mechanistic discussion of the dechalcogenation methods developed so far. Taking advantage of recently published reports, it also clarifies some unexpected desulfurization reactions that were observed in the past and for which no explanation was provided at the time. Additionally, the review includes a discussion on principal desulfurization methods within the framework of newly introduced green chemistry metrics and toolkits, providing a well-rounded exploration of the subject. [ABSTRACT FROM AUTHOR]

Excess hypochlorite (ClO−) is harmful to living organisms and can cause various oxidative diseases in the human body. Owing to the toxicity of ClO−, the development of efficient fluorescence sensors to track ClO− is necessary. In this work, we report a novel thiourea‐based fluorescent turn‐on sensor 1‐(9‐ethyl‐9H‐carbazol‐3‐yl)‐3‐(naphthalen‐1‐yl)thiourea (ECNT) for recognizing ClO−. ECNT can detect ClO− with high selectivity, relatively low interference with other analytes, and a significantly fast response time (<1 s) through a desulfurization reaction. The detection limit of ECNT for ClO− is calculated as 5.59 μM. Of note, ECNT is a chemosensor that reacts the fastest with ClO− among the reported thiourea‐based fluorescence turn‐on sensors for detecting ClO−. The response mechanism of ECNT to ClO− is demonstrated through 1H NMR titration, ESI mass, and density functional theory calculations. [ABSTRACT FROM AUTHOR]

In this study, the adsorption of dibenzothiophene sulfone (DBTO) was investigated using clay minerals as adsorbents. Raw bentonite (BR) and raw activated clay (ACR) were impregnated with Fe3+ and Fe6+, creating bentonite-Fe3+ (BF3), bentonite-Fe6+ (BF6), activated clay-Fe3+ (ACF3), and activated clay-Fe6+ (ACF6). The surface functional groups, surface morphology, and surface area of the raw and modified adsorbents were studied through Fourier transform infrared spectroscopy, a scanning electron microscope, and Brunauer, Emmett, and Teller analysis, respectively. Batch experiments on simulated oil were done to test the effect of adsorption time (0.5–24 h), adsorption dosage (0.3–1.5 g), and adsorption temperature (30–50 °C). The results of the experiments showed the suitability of the pseudo-second order kinetic model on the clay adsorbent and sulfone system. This suggests that chemisorption is the rate-limiting step of the reaction. Equilibrium isotherms indicated the adherence of DBTO onto BR and BF3 to the Freundlich model, implying the heterogeneous adsorption of the sulfones onto the adsorbents. The systems of DBTO with BF6, ACR, ACF3, and ACF6 showed a better fit with the Dubinin-Radushkevich model. This denotes that adsorption happens through the filling of sulfones of the micropores on the adsorbent. Lastly, thermodynamic studies revealed the endothermic and non-spontaneous nature of the clay adsorbents and sulfone systems. The experiments showed that the impregnation of Fe3+ and Fe6+ lowered the desulfurization ability of the adsorbents. This could be due to the iron ions being hard acids and the sulfones being soft bases, thus showing lower compatibility than the raw counterparts of the adsorbents. Comparison with related studies showed that the prepared adsorbents, namely BF3 (5.1 mg g−1) and BF6 (6.4 mg g−1), had a higher adsorption capacity than Ni2+-loaded activated carbon (4.9 mg g−1) and activated clay (4.1 mg g−1). The study shows that BR (7.2 mg g−1) is the best-performing adsorbent, which can be set as the direction for future research. This study is a step toward the commercialization of oxidative desulfurization methods. [ABSTRACT FROM AUTHOR]

This study evaluates the efficacy of the Thiopaq bio-desulfurization system at the Daegu Bangcheon-ri Sanitary Landfill in Korea over 1 year focusing on operational insights and microbial dynamics. The system employs sulfur-oxidizing bacteria (SOBs) to convert hydrogen sulfide (H2S) in landfill gas (LFG) into elemental sulfur. Key findings include maintaining over 96% H2S removal efficiency despite operational challenges such as sulfur clogging and foam formation. Significant microbial community shifts were observed, with Thioalkalibacter halophilus remaining robust, Alkalilimnicola ehrlichii declining, and Halothiobacillus kellyi becoming more prominent, especially during new well installations with high thiol (methanethiol) concentrations. Scanning electron microscopy revealed distinct morphological characteristics of bio-sulfur under varying conditions contributing to process optimization. Our results underscore the necessity for continuous monitoring and adaptive management of microbial populations and system parameters to effectively handle fluctuating LFG compositions and operational conditions. This study provides substantial guidance for enhancing LFG quality and bio-sulfur production in large-scale landfills. [ABSTRACT FROM AUTHOR]

The semi-dry nonthermal plasma-induced ozone injection process is a promising desulfurization and denitration method for flue gases emitted from glass melting furnaces. To design a reactor for this process in an actual plant, it is necessary to evaluate the effect of the residence time of the flue gases in the reactor on desulfurization and denitration. In this study, the inner volume of the reactor was vertically divided into ten sections corresponding to the temperature measurement points. The residence time of each section was calculated to determine the residence time in the reactor. The effect of residence time on desulfurization and denitrification was then elucidated. In addition, the nitrite (${\rm{NO}}_{\rm{2}}^{\rm{ - }}$ N O 2 − ) and nitrate (${\rm{NO}}_{\rm{3}}^{\rm{ - }}$ N O 3 − ) ions in the droplets collected in the wastewater tank connected to the bottom of the reactor and in the condensates in the condensers downstream of the reactor were measured to evaluate the nitrogen balance with respect to the removed NOx. [ABSTRACT FROM AUTHOR]

Iron-assisted pyrolysis (Fe-assisted pyrolysis) is a high-efficiency technique to remove sulfur from low-rank coal. However, the sulfur removal mechanism of Fe-assisted pyrolysis did not compressively address. For filling this gap, this study explored the sulfur removal mechanism of diphenyl sulfone during Fe-assisted pyrolysis based on the factor optimization of desulfurization performance. The iron powder under the optimal conditions of Fe-assisted pyrolysis was characterized with X-ray diffractometer (XRD) and X-ray photoelectron spectroscopy (XPS), showing that FeS and some FeS2 were formed on the surface of post-pyrolysis iron powder. Gas chromatography (GC) analysis manifested that the addition of iron powder in the pyrolysis process could considerably reduce the SO2 emission. GC and Fourier transform infrared spectrometer (FTIR) analyses demonstrated that there was C–S bond broken in the diphenyl sulfone structure during Fe-assisted pyrolysis. From the results of thermogravimetry-mass spectrometry (TG-MS), the addition of iron powder in the pyrolysis process could enhance the reaction rate and reduce the temperature required for the reaction. We believe that the results of the present study provided a theoretical basis for a profound understanding of the desulfurization mechanism of Fe-assisted pyrolysis. [ABSTRACT FROM AUTHOR]

The Keggin‐type P‐Mo‐W polyoxometalate‐based ionic liquids ([VimAm]Br‐POM, POM is PMo6W6O40) were facilely supported on the green fiber (CA) to obtain a kind of bar‐shaped catalyst. The [VimAm]Br‐POM@CA showed an outstanding oxidative desulfurization performance for model oil and real oils with H2O2 as oxidant, mainly due to the dual role of the [VimAm]Br‐POM with the high activity and its excellent dispersion on CA. The dibenzothiophene (DBT) in model oil could be almost completely removed with [VimAm]Br‐POM@CA‐2 in 60 min at 60 °C without adding other extractants, in which [VimAm]Br acts as this role. Meanwhile, the influences of reaction temperature, molar ratio of H2O2/S, catalyst dosage, and different sulfur‐containing compounds were also investigated. Interestingly, the pretty low activation energy (0.1875 kJ/mol) has been achieved, and no significant loss of activity even after being reused for 5 cycles. The combination of IL‐POM and CA is an efficient strategy to obtain a newly kind desulfurization catalyst, with remarkable results on catalytic efficiency and reuse ability at the same time. [ABSTRACT FROM AUTHOR]

This study examined the desulfurization capacity of a high specific surface area activated carbon (AC) and its modifications for real diesel fuel of different sulfur concentrations. Adsorbent's evaluation strategy included desulfurization experiments under batch and continuous conditions. Batch experiments were conducted by a homogeneous stirring of adsorbent and diesel fuel, while for the continuous tests, a fixed bed reactor was used to generate breakthrough desulfurization curves. In the fixed bed reactor's tests, the sulfur removal – considering an initial concentration of about 6 parts per million weight (ppmw) – was substantial for the first 30 ml fuel per gram of adsorbent. For this specific quantity, the total sulfur content of the cumulatively processed fuel was less than 2 ppmw. The batch experimental results are elaborated using a mechanistic kinetic model for batch adsorption considering the total sulfur mass balance. Mass transfer coefficients are derived this way for all the conditions and adsorbents tested. The adsorption equilibrium data from batch experiments are utilized to model the fixed bed experimental results. In this way, mass transfer coefficients for the fixed bed are derived. In any case, the modeling results indicate that sulfur is not the only adsorbate of the process, but other adsorbates act competitively to sulfur, thereby complicating the process. [ABSTRACT FROM AUTHOR]

Zinc‐based sorbents with ordered mesoporous structure were modified with aluminium and the key factors in the preparation were optimized based on the results of desulphurization tests performed in a fixed‐bed reactor with simulated coal gas. It was shown that the sorbents for hydrogen sulphide removal reached an optimum sulphur capacity of 9.14% when prepared under conditions of 10.0 crystalline pH, 30:1 Si:Al molar ratio, 0.32:1 Zn:Si molar ratio, and 1:3 Zn:TAA molar ratio. The sorbent without aluminium was synthesized synchronously as a comparison sample to investigate the effect of aluminium addition on the desulphurization properties. The surface acidity of the sorbents is enhanced by the addition of aluminium, and the sulphur capacity of the aluminium‐doped sorbent is consequently lower compared to that of aluminium‐free sorbent. Nevertheless, the aluminium‐doped sorbent shows a significant advantage in stability of performance over multiple desulphurization–regeneration cycles and reaches an 81% retention rate of sulphur capacity after five desulphurization, while the aluminium‐free sorbent is only 51% in contrast. The characterization results manifest that aluminium enters the carrier skeleton and increases the wall thickness, which alleviates the collapse of the carrier pore channels and the agglomeration of the active components during the desulphurization process. Stable pore structures and highly dispersed active components facilitate the mass transfer in the reaction process after multiple desulphurization. As a result, the aluminium‐doped sorbent exhibits better performance stability in high temperature coal gas desulphurization. [ABSTRACT FROM AUTHOR]

The extensive industrial applications of fuel oil, a critical strategic resource, are accompanied by significant environmental and health concerns due to the presence of sulfur‐containing compounds in its composition, which result in hazardous combustion waste. Extensive research has been conducted to develop technologies for low‐vulcanization fuel production to address this issue. Consequently, the investigation of catalysts for environmentally friendly and safe photocatalytic desulfurization becomes imperative. To that end, we have designed efficient MIL‐101(Fe)/CQDs@g‐C3N4 (MIL101/CDs‐C3N4) Z‐scheme heterojunction photocatalysts with high carrier separation and mobility through a thermal polymerization‐hydrothermal strategy. The high concentration of photogenerated carriers facilitates the activation of oxygen and H2O2, leading to increased production of ROS (⋅O2−, ⋅OH, h+), thereby enhancing the photocatalytic desulfurization (PODS). Additionally, DFT (Density functional theory) calculations were utilized to determine the electron migration pathways of the catalysts and adsorption energies of DBT (dibenzothiophene). Moreover, Gibbs free energy calculations indicated that MIL101/CDs‐C3N4 exhibited the lowest activation energy for oxygen and H2O2. The mechanism of photocatalytic desulfurization was proposed through a combination of theoretical calculations and experimental studies. This study provides guidance for the development of MOF‐based Z‐scheme systems and their practical application in desulfurization processes. [ABSTRACT FROM AUTHOR]

This work unveils a route for a new generation of heterogeneous polyoxometalate (POMs) based catalysts associated to the preparation of hybrid materials as a triad of POMs, mesoporous silica (SBA‐15) and microporous MOF structures (MOF‐808). The prepared catalyst, PMo12@MOF‐808@SBA‐15, with the main active center the phosphomolybdic acid (PMo12), was successfully applied for the desulfurization of a multicomponent fuel. Its oxidative catalytic performance showed to be considerable superior to the isolated POM@MOF and able to be recycled for more catalytic cycles without active loss. The higher catalytic performance seems to be directly related with the preparation of a more amorphous MOF structure within the channels of SBA‐15, in the presence of active POM guests. [ABSTRACT FROM AUTHOR]

In recent years, researchers are looking for ways to reduce the amount of sulfur in kerosene. Therefore, desulfurization of kerosene is considered an important commercial and environmental process. Among the hard and complicated methods available for the desulfurization process, natural zeolites can be a suitable alternative for the desulfurization of oil products due to their economic efficiency, biocompatibility, and natural abundance of oil reserves. In this research, natural zeolite (clinoptilolite) was modified with CuO nanoparticles and used as adsorbent for desulfurization of kerosene. The effect of important parameters such as adsorbent dose, pH of solution and initial adsorbate concentration were investigated. Results indicated the optimum conditions as follows: dose of adsorbent 2 g, pH 10 and the adsorbate dose 200 ppm. Results showed that the modified adsorbent is a suitable, low-cost and good efficiency for the desulfurization process of kerosene. [ABSTRACT FROM AUTHOR]

Boric acid is a dilute or mild acid derived from boron, and it is available in a water-soluble form as a white powder. Strong acids are generally preferred to remove ash and sulfur from coal. However, consumption of these strong acids harms the environment. Therefore, it is necessary to improve the leaching possibilities of weak acids. Also, a combination of beneficiation methods may need to be used to achieve the desired quality and environmental compatibility of coal. In this study, a combination of bioleaching and chemical experiments was employed to eliminate ash and sulfur from Sivas Kangal lignite coal. Initially, bioleaching experiments were conducted on lignites with high ash and sulfur contents by bioreactor with Acidithiobacillus ferrooxidans. Following this, in the second phase of experiments, boric acid leaching was employed to beneficiate Sivas/Turkey lignites through chemical methods. Additionally, the effect of glycerol on the leaching efficiency of boric acid, which is a weak acid, was investigated. Experimental findings have shown that combination methods provide better results in ash and sulfur removal from lignite coal. Finally, a clean coal product with 19.80% ash and 2.89% S content was obtained by combination methods to the lignite coal (46.60% ash and 4.99% S). [ABSTRACT FROM AUTHOR]

One of the current challenges is the reduction of sulfur emitted into the atmosphere, usually in the form of sulfur oxides generated by fossil fuel combustion. To achieve this goal, the sulfur content should be reduced in fuel. In this context, vanadium-containing materials based on SBA-15 mesoporous silica supports and two different sources of vanadium were prepared, characterized, and applied as catalysts for oxidative desulfurization (CODS) and extractive oxidative desulfurization processes (ECODSs). The novelty of this work was the comparative study of vanadium-containing materials in two desulfurization systems. The properties of the catalysts, the concentration and state of vanadium species, and their role in the catalytic process were examined by low-temperature nitrogen physisorption, XRD, UV-Vis, XPS, and chemisorption of pyridine combined with FTIR spectroscopy. The catalytic performance of the material prepared using ammonium metavanadate was superior to that of the catalyst obtained using vanadium(IV) oxide sulfate, which was explained by a higher concentration of vanadium species on the surface of the support and their lower oxidation state in the former. Both types of catalysts showed high activity and stability in the ECODS process. [ABSTRACT FROM AUTHOR]

Novel and highly stable nitronyl nitroxide radical (NIT) derivatives were synthesized and coated on the surface of multi-walled carbon nanotubes (MWCNTs) to improve their desulfurization performance. They were characterized by FTIR, UV-vis, SEM, XRD, Raman spectroscopy and ESR. Thiophene in fuel was desulfurized by molecular O2, and the oxidation activity of these compounds was evaluated. At a normal temperature and pressure, the degradation rates of thiophene by four compounds in 4 h can reach 92.66%, 96.38%, 93.25% and 89.49%, respectively. The MWCNTs/NIT-F have a high special activity for the degradation of thiophene, and their desulfurization activity can be recycled for five times without a significant reduction. The mechanistic studies of MWCNTs/NIT composites show that the ammonium oxide ion is the key active intermediate in catalytic oxidative desulfurization, which provides a new choice for fuel oxidative desulfurization. The results show that NIT significantly improves the photocatalytic performance of MWCNTs. [ABSTRACT FROM AUTHOR]

In recent years, TiO2-based catalysts have received extensive attention from researchers for their excellent oxidative desulfurization (ODS) performances. In this paper, a series of mesoporous TiO2/SiO2 catalysts with different TiO2 loadings are prepared, using an incipient wetness impregnation method with agricultural waste rice husk as both the silicon source and mesoporous template and tetrabutyl titanate as the titanium source. The effect of different TiO2 loadings on the ODS performance of the samples is investigated, and the appropriate TiO2 loading is 2.5%. Compared with pure TiO2, the 2.5%TiO2/SiO2 sample exhibits high catalytic activity for oxidative desulfurization. This is, on the one hand, due to the high specific surface area and mesopore volume of the 2.5%TiO2/SiO2 sample. On the other hand, it is due to the uniform dispersion of TiO2 grains with an average diameter of 6.1 nm on the surface of the mesoporous SiO2 carrier, which greatly increases the active sites of the 2.5%TiO2/SiO2 sample, thus improving the catalytic activity of the sample. The recycling performances of the 2.5%TiO2/SiO2 sample are further investigated. The results show that, after fifteen cycles, the 2.5%TiO2/SiO2 sample still maintains high conversions of dibenzothiophene (99.8%) and 4,6-dimethyldibenzothiophene (99.7%) without deactivation. In addition, the 2.5%TiO2/SiO2 sample treated with TBHP aqueous solution is characterized by the technique of UV-Vis, and the Ti-peroxo (Ti-OOtBu) species, the active intermediate for the ODS of bulky organic sulfides, is successfully captured. Finally, a possible reaction mechanism for the ODS process over the 2.5%TiO2/SiO2 sample is proposed. [ABSTRACT FROM AUTHOR]

Unexpectedly facile dearomative intramolecular (4+3) cycloadditions of thiophenes with epoxy enolsilanes, providing sulfur‐bridged cycloadducts, are reported. A total of fifteen thiophene substrates have been found to undergo (4+3) cycloaddition smoothly to produce endo and exo (4+3) adducts in yields of up to 83 % with moderate to good diastereoselectivity. Complete conservation of enantiomeric purity was observed when the optically enriched epoxide was used. The desulfurizing transformations of the sulfur‐bridged skeleton of the cycloadducts provide functionalized 6,7‐fused bicyclic frameworks consisting of 1,3‐cycloheptadiene subunits. Density functional theory calculations reveal the origins of the facile dearomatization of thiophenes in these (4+3) cycloadditions. [ABSTRACT FROM AUTHOR]

Reactive black 5 (RBk5) is a refractory azo dye that constitutes a serious threat to the environment and humans. Herein, natural bornite (Nbo) was utilized to activate persulfate (PDS) for the RBk5 removal. The particle size of the Nbo catalyst was optimized and the RBk5 degradation rate constant that responded positively to the particle size of the Nbo catalyst was exhibited. Then, the operational factors affecting RBk5 removal were comprehensively investigated. With the addition of 1.5 g L−1 Nbo and 1.5 mM PDS, 99.05% of the RBk5 (20 mg L−1) was removed in 150 min compared with 0.46% removal with PDS only, which was caused by the additional reactive oxygen species (ROS) produced by the synergistic action of Fe-Cu bimetallic metal and reductive sulfur species. The Nbo catalyst presented high stability and reusability toward RBk5 removal. Identification of reactive oxygen species revealed that ${\rm SO}_4^{\cdot -}$ SO 4 ⋅ − , ·OH, ${\rm O}_2^{\cdot -}$ O 2 ⋅ − and 1O2 collectively participated in RBk5 removal. Additionally, a possible degradation pathway for RBk5 was proposed, including cleavage of the azo, C–S and S–O bonds, hydroxylation, hydrolyzation, direct oxidation and other pathways. This work developed a highly effective and low-cost natural mineral-based bimetallic sulfide material for PDS activation for the degradation of contaminants and environmental remediation. [ABSTRACT FROM AUTHOR]

This work analyzes vacuum gas oil (VGO) and hydrocracking products of this feed blended with polymethylmethacrylate (PMMA) or polyethylene terephthalate (PET) to clarify the oxygen, nitrogen, and sulfur removal pathways in these complex mixtures. Hydrocracking reactions are conducted in a semi‐batch reactor with a Pt−Pd/HY bifunctional catalyst at 400 °C and 80 bar for 300 min with 10 wt % waste plastic using 0.1 catalyst/feed weight ratio. The samples are analyzed using various techniques, including high‐resolution mass spectrometry, providing an improved, more detailed analytical representation. The results demonstrate the synergistic effect of cofeeding oxygenated plastics to the VGO, altering the preferential reaction pathways of heteroatom‐containing species in the following order: nitrogen, oxygen, and sulfur. We assess the nature of the species from the gathered data, establish plausible reaction mechanisms, and evaluate the catalyst's role. [ABSTRACT FROM AUTHOR]

The formation of the solid phases CaS, 3CaO.SiO2 and CaO.Al2O3 around the lime particle decreases the efficiency of desulfurization by the kanbara reactor (KR) process. The addition of fluxes reduces the formation of these phases. The addition of Al and Si can also have this effect, depending on the added levels. In this study, different mixtures based on CaO with different levels of fluorspar, sodalite (Nepheline Syenite), and SiO2 and Al2O3 content were studied and used in the desulfurization process of hot metal. These mixtures were added to a bath of liquid hot metal at 1400 °C. All experiments were performed with mechanical agitation. Samples were taken at times of 5, 10, 15, and 20 min, and analyses were performed to evaluate the variation of sulfur over time. The Thermo‐Calc software was used to determine the formed phases, solid fraction, and liquid fraction of the different mixtures. With this data, different values of the Global Desulfurization Factor (FGDeS) were calculated, which was developed to evaluate and predict the efficiency of hot metal desulfurizing mixtures by the KR process. The results of showed that fluorspar was more efficient than sodalite. The FGDeS had a correlation factor (R2) above 0.9 with the desulfurization efficiency. [ABSTRACT FROM AUTHOR]

The recycling and recovery of value-added secondary raw materials such as spent Zn/C batteries is crucial to reduce the environmental impact of wastes and to achieve cost-effective and sustainable processing technologies. The aim of this work is to fabricate reduced graphene oxide (rGO)-based sorbents with a desulfurization capability using recycled graphite from spent Zn/C batteries as raw material. Recycled graphite was obtained from a black mass recovered from the dismantling of spent batteries by a hydrometallurgical process. Graphene oxide (GO) obtained by the Tour's method was comparable to that obtained from pure graphite. rGO-based sorbents were prepared by doping obtained GO with NiO and ZnO precursors by a hydrothermal route with a final annealing step. Recycled graphite along with the obtained GO, intermediate (rGO-NiO-ZnO) and final composites (rGO-NiO-ZnO-400) were characterized by Wavelength Dispersive X-ray Fluorescence (WDXRF) and X-ray diffraction (XRD) that corroborated the removal of metal impurities from the starting material as well as the presence of NiO- and ZnO-doped reduced graphene oxide. The performance of the prepared composites was evaluated by sulfidation tests under different conditions. The results revealed that the proposed rGO-NiO-ZnO composite present a desulfurization capability similar to that of commercial sorbents which constitutes a competitive alternative to syngas cleaning. [ABSTRACT FROM AUTHOR]

Achieving the clean utilization of coal is the priority of the coal industries. This paper proposed an efficient electrochemical technology for coal desulfurization before combustion. It was explored that citric acid can chemically provide enough acidic conditions for desulfurization reactions, and the ultrasonic-enhanced treatment physically helps to remove sulfur from coal due to its cavitation effect and mechanical effect. So the experiments of ultrasound-assisted electrochemical desulfurization using citric acid as the electrolyte solution were conducted. They combined physical and chemical methods to effectively remove sulfur from coal. The optimal operating parameters of the desulfurization effect were achieved by qualitative and quantitative analysis of coal samples(coal slurry concentration of 66 g/L, electrolysis time of 8 h, electrolyte concentration of 1.5 mol/L, electrolysis voltage of 4 V, electrolysis temperature of 30°C, ultrasonic strengthening time of 1 h and ultrasonic intensity of 320 W.). The total sulfur removal efficiency reached 45.09%. The electrolytic desulfurization experiments removed samples' sulfur contents, ash contents, and water. The crystal structures of gypsum, white iron ore, zinc sulfide, and the molybdenite mineral composition were also destroyed for purification. Gaussian simulations showed that C-S bonds and S-S bonds contained in non-thiophene organic sulfur are easier to remove, and S-S bonds are more likely to break than C-S bonds. This study realized the promotion of desulfurization with the ultrasonic wave and citric acid solution. It provides a new idea of synergistic desulfurization and is beneficial to reduce atmospheric sulfur pollution. [ABSTRACT FROM AUTHOR]

Producing an eco-friendly fuel with the least amount of sulfur compounds has been an ongoing issue for petroleum refineries. In this study, bentonite (which is a cheap material and is locally available in abundance) is employed to prepare a nano-silica catalyst with a high surface area to be used for the oxidative desulfurization of kerosene. Two composite catalysts of Fe/silica were supported on CAT-1 (0% HY-zeolite and 100% nano-silica) and CAT-2 (20% HY-zeolite and 80% nano-silica). The activity of the catalysts was evaluated in a batch ODS (oxidative desulfurization) process at temperatures of 30, 60, 90, and 120 °C, a pressure of 1 atm, and a reaction time of 30, 60, 90, and 120 min using 120 L/h of air as the oxidant. The results revealed that the highest total sulfur removal efficiency was 50% and 87.88% for 100% nano-silica (CAT-1) and 80% nano-silica (CAT-2), respectively. The experimental data were then used to construct and validate an accurate mathematical model of the process. The operational parameters for eliminating more than 99% of sulfur and producing eco-friendly fuel were then achieved by using the model. The testing methods for these characterizing materials included X-ray diffraction (XRD), thermal gravimetric examination (TGA), X-ray fluorescence (XRF), and surface area (BET). The outcomes indicated that the addition of HY-zeolite increased the activity of the catalyst (CAT-2 > CAT-1). [ABSTRACT FROM AUTHOR]

A possibility of using aluminum hydroxide, a product of processing of the adsorbent that lost its sorption activity in purification of a polyethylene solution cyclohexane, was demonstrated in the synthesis of aluminum kaolin borate supports for hydrodesulfurization catalysis in oil refining. The influence of typical impurities V, Ti and Na in the composition of the spent adsorbent on the physicochemical and catalytic properties of supports and catalysts was determined. Alumina-kaolin-borate catalyst carriers with the Ti content of approx. 0.2% have been prepared by atomic layer deposition (ALD) of TiCl4 onto the granules. A positive effect of molecular layering with TiO2 has been revealed by temperature programmed reduction and oxidation in combination with hydrodesulphurization activity testing. [ABSTRACT FROM AUTHOR]

An efficient method for the oxidative transformation of thioamides and thioketones to their oxygen analogues with singlet oxygen is reported. Singlet oxygen was produced in situ from the fragmentation of the trans-5-hydroperoxy-3,5-dimethyl-1,2-dioxolane-3-yl ethaneperoxate in the presence of KOH, and it has been explored as an effective oxidant for oxidative desulfurization of thioamides and thioketones. This protocol provides amides and ketones in excellent yields (80–90%) at room temperature under mild conditions. The thioamides reacted very well with this reagent system. The conjugation of neighboring NH and C=S groups appears to enhance yields for thioamides. Further investigation showed that this reagent system is also an efficient system for deprotection of thionoesters to esters. [ABSTRACT FROM AUTHOR]

The desulfurization capacity of top slag in the process of pre-desulfurization of hot metal containing vanadium and titanium was researched. The top slag system of CaO-SiO2-MgO-Al2O3-TiO2-VOx that was formed by blast furnace slag and a CaO desulfurization agent reduced the sulfur in hot metal from 0.08 wt.% to 0.02 wt.%. It was found that the resulfurization of the slag happened in the later periods of the desulfurization process. The vanadium–titanium oxides were both acidic in the desulfurization slag. TiO2 and VOx reacted with the basic oxides to form CaTiO3 and MgV2O4 at 1623 K, which reduced free CaO and was not conducive to top slag desulfurization. The results of calculation showed that the top slag desulfurization accounted for 15% of the total desulfurization. Using the ionic and molecule coexistence theory of slag structure, it is shown that the desulfurization efficiency could be enhanced by adjusting both the amount of desulfurization agent and the composition of the blast furnace slag before pre-desulfurization. [ABSTRACT FROM AUTHOR]

This study presented the investigation on the microstructure characteristics and the interaction among asphalt, crumb rubber (CR) and modifiers (softener, activator, and cross-linking agent) of crumb rubber compound modified asphalt (CRCMA) at process phases by microscopic testing techniques. The results showed that CRCMA had excellent rheological properties at high or low-temperature. The softener was only physically mixed with asphalt and did not change the microscopic morphology of the asphalt. The activator can break some of the chemical bonds of CR and promote the desulphurization degradation reaction which makes the asphalt show a large number of small-body type mesh structures and a small amount of chains in microscopic morphology. The crosslinking agent provided a source of sulphur to induce the crosslinking reaction which resulted in an increase in the reticulation of CRCMA. Finally, a modification mechanism model and the evolution mechanisms based on the microstructure characteristics at preparation phases of CRCMA were proposed. [ABSTRACT FROM AUTHOR]

The emission of sulfur compounds during the combustion of coal is the main cause of atmospheric pollution and poses a threat to human health and the ecosystem. Thus, elimination of sulfur compounds from coal before its use is compulsory, and hence, coal desulfurization has become the key solution. In the present study, ultrasonic-assisted oxidative desulfurization of coal was conducted utilizing H2O2 in the presence of choline chloride/Acetic acid (ChCl/AcA) deep eutectic solvents (DESs). Three coal samples from different areas of Punjab were received for the investigation. The DES ChCl/AcA possesses sulfur removal efficiency of up to 58–64% pyritic sulfur, 54–63% sulfate sulfur, and 48–54% total sulfur from different coal samples. In addition to inorganic sulfur removal, a considerable decrease in organic sulfur 38–41% has been obtained using ultrasound-assisted oxidative desulfurization. FTIR study has shown that the treated coal samples have decreased sulfur contents as compared to untreated coal samples along with no significant change in the calorific values. These outcomes open new paths headed for more energy-effective and cleaner coal, utilizing cost-effective DESs. [ABSTRACT FROM AUTHOR]

The impurity sulfur in lead–zinc-bearing hematite–limonite ore mainly exists in the form of galena, sphalerite, pyrite, and natural sulfur, and deep reduction roasting–low intensity magnetic separation does not effectively remove sulfur in a low valence state, which affects the quality of iron ore concentrate. Thereby, the desulfurization mechanism of the oxidative roasting process was investigated via XRD, TG, microscopy, thermodynamics, electron probe micro-analysis–energy-dispersive spectroscopy (EPMA-EDS) analyses. It is noted that hematite–limonite ore contains the valuable components of Fe2O3 (59.72 wt.%), SiO2 (15.43 wt.%), which are 46.32% of total of Fe, with a numerous number of impurities such as S (3.34 wt.%), Pb (1.50% wt.%), Zn (1.25% wt.%), etc. Microscopic identification revealed a complex relationship between hematite, pyrite, galena, sphalerite, and silica inclusions. Therefore, optimal roasting conditions were 60 min and 1050°C, respectively, where the total desulfurization rate was 92.33%, with the desulfurization rate of low valent sulfur reaching 98.64%. Meanwhile, thermodynamic and XRD analyses showed that pyrite was oxidized to ferrous oxide, magnetite, and hematite, etc., sphalerite was oxidized to zinc oxide, while galena was oxidized to lead oxide, and the difficulty of removing products such as PbO·PbSO4, and PbSO4 is noted [ABSTRACT FROM AUTHOR]

The primary energy source in developing countries, including Indonesia, is fossil energy. Therefore, evaluating the environmental impact of coal-fired steam power plants is crucial, but limited. Comprehensive scientific analysis is required to develop appropriate alternative measures. This research aims to analyze the life cycle impact of the coal power plant at the gate, including the coal yard, coal crusher, boiler, turbine, and generator, with the functional unit of 1 kWh of electricity produced. This research provides clear recommendations for mitigating emissions from the main contributing units. The analysis reveals the highest impact in the climate change potential category (1.40 × 10-1 kg CO2 eq/kWh), while the smallest impact was recorded in the Eutrophication potential category (7.55 × 10-4 kg PO4 eq/kWh), with no impact on ozone depletion in the stratosphere. The operation of boiler and generator units (gate hotspots) are the main contributors to climate change impacts, including carbon dioxide (9.25 × 10-2 kg CO2), sulfur dioxide (8.21 × 10-3 kg SO2), and nitrogen dioxide (7.55 × 10-4 kg PO4). Alternative programs that may be implemented to reduce emissions include co-firing and installation of flue gas desulfurization and low NOx burner. The findings of this research provide guidance for developing a policy framework to promote more environmentally friendly coal power plants, thereby achieving greater energy sustainability. [ABSTRACT FROM AUTHOR]

This study converted pig dung (PD) with garlic (Allium sativum) peel extract (GPE) to adsorbents (dried pig dung (DPD), activated carbon DPD (ACDPD) and GPE impregnated DPD (EDPD) and GPE impregnated ACDPD (EACDPD)), applied in the removal of Dibenzothiophene (DBT) from diesel. The four adsorbent samples (DPD, EDPD, ACDPD and EACDPD) were used for the removal of Dibenzothiophene (DBT) through batch desulfurization process at different experimental condition (dosage: 100 to 500 mg; time: 30 to 120 min and temperature: 25 to 50 °C) and appropriately characterized. EACDPD proved to be an adsorbent that can be employed for the desulfurization of diesel. The optimum equilibrium condition was achieved at 90 min for the removal of 67.76% of DBT applying a dosage of 178 mg, temperature of 45 °C and agitation of 260 rpm for the desulfurization process. The kinetic of the desulfurization process was best described by pseudo second order rate expression while the best isotherm model that best fitted the desulfurization data was Temkin model. The removal of DBT from diesel and its adsorption on EACDPD was an endothermic reaction with estimated change in enthalpy and entropy of 34.41 kJ/mol and 68.69 J/mol K respectively. Characterization showed transformation to the surface of the modified adsorbent (EACDPD) after chemical, thermal and impregnation from amorphous to plat like with improvement in micropore and mesopore of the adsorbent (EACDPD) while it was deduced that the presence of Mg and Zn in EACDPD enhance removal of DBT from diesel. This research is applicable in sustainable development goals (SDG) 7 and 11 respectively.Article Highlights: Pig Dung was thermally and green modified for the removal of removal of Dibenzothiophene (DBT) from oil. Optimal condition for the removal efficiency of produced adsorbents was presented Reusability potential of the produced adsorbent in removal of DBT was established. [ABSTRACT FROM AUTHOR]

A new landfill-gas-to-biomethane process prescribing decarbonation/desulfurization via gas–liquid membrane contactors and siloxane absorption using Selexol are presented in this study. Firstly, an extension for an HYSYS simulator was developed as a steady-state gas–liquid contactor model featuring: (a) a hollow-fiber membrane contactor for countercurrent/parallel contacts; (b) liquid/vapor mass/energy/momentum balances; (c) CO2/H2S/CH4/water fugacity-driven bidirectional transmembrane transfers; (d) temperature changes from transmembrane heat/mass transfers, phase change, and compressibility effects; and (e) external heat transfer. Secondly, contactor batteries using a countercurrent contact and parallel contact were simulated for selective landfill-gas decarbonation/desulfurization with water. Several separation methods were applied in the new process: (a) a water solvent gas–liquid contactor battery for adiabatic landfill-gas decarbonation/desulfurization; (b) water regeneration via high-pressure strippers, reducing the compression power for CO2 exportation; and (c) siloxane absorption with Selexol. The results show that the usual isothermal/isobaric contactor simplification is unrealistic at industrial scales. The process converts water-saturated landfill-gas (CH4 = 55.7%mol, CO2 = 40%mol, H2S = 150 ppm-mol, and Siloxanes = 2.14 ppm-mol) to biomethane with specifications of CH4MIN = 85%mol, CO2MAX = 3%mol, H2SMAX = 10 mg/Nm3, and SiloxanesMAX = 0.03 mg/Nm3. This work demonstrates that the new model can be validated with bench-scale literature data and used in industrial-scale batteries with the same hydrodynamics. Once calibrated, the model becomes economically valuable since it can: (i) predict industrial contactor battery performance under scale-up/scale-down conditions; (ii) detect process faults, membrane leakages, and wetting; and (iii) be used for process troubleshooting. [ABSTRACT FROM AUTHOR]

To investigate the macroscopic mechanical properties and failure evolution mechanism of desulfurization gypsum–fly ash fluid lightweight soil, a microscale numerical model using PFC2D (Particle Flow Code) was constructed. Uniaxial compression tests were conducted to determine the microscopic parameters of the model, extracting information on the discrete fracture network type, quantity, age, and particle displacement trend. The crack morphology and propagation evolution of desulfurization gypsum–fly ash fluid lightweight soil were explored, and the destructive properties of desulfurization gypsum–fly ash fluid lightweight soil material were evaluated through energy indicators. The research findings suggest that the discrete element numerical model effectively simulates the stress–strain curve and failure characteristics of materials. Under uniaxial compression conditions, microcracks dominated by shear failure occur in the initial loading stage of desulfurization gypsum–fly ash fluid lightweight soil, with a through crack dominated by tensile failure appearing once the load exceeds the peak stress. The dissipated energy evolution in the flow state of desulfurization gypsum–fly ash fluid lightweight soil is relatively gentle, leading to delayed cracking after surpassing the peak stress point. [ABSTRACT FROM AUTHOR]

Silicic acid solution, which is prepared from water glass followed by extraction with tetrahydrofuran (THF), is focused on an environmentally friendly and inexpensive source of silica. In this study, we aimed the preparation of bulk porous silica with low environmental impact and cost, and desulfurization of its supported ZnO was investigated. Bulk porous silica was prepared by the condensation of silicic acid/THF in the presence of Pluronic P123. Suitable condition was investigated for the formation of crack-free bulk body with high surface area and reproducibility under the molar ratio of H2O/Si and Si/Pluronic P123 on 121 and 100, respectively. From nitrogen adsorption–desorption measurements, this bulk porous silica was categorized into micro–mesoporous silica. Moreover, Pluronic P123 was extracted and recycled. Bulk porous silica-supported 15 wt% ZnO was prepared by the impregnation of ZnCl2 followed by calcination in air. The desulfurization ability was 8.7 mg/g. Highlights: Micro–mesoporous silica bulk bodies were prepared using silicic acid derived from water glass. Pluronic P123 was recycled and micro–mesoporous silica could be prepared by using recycled Pluronic P123 with high reproducibility. Bulk micro–mesoporous silica-supported ZnO showed a desulfurization ability. [ABSTRACT FROM AUTHOR]

When SO2 and NO2 are simultaneously absorbed into limestone slurry, the SO32- (including HSO3-) ions formed by the hydrolysis of SO2 enhance the absorption rate of NO2. However, NO2 absorption decreases due to the oxidation of SO32- in the presence of O2. To address this issue, simultaneous absorption was performed by adding organic additives: formic, acetic, propionic acid, monoethanolamine (MEA), diethanolamine (DEA), and triethanolamine (TEA). These limestone slurries were denoted FS, AS, PS, MS, DS, and TS, respectively. As the acidity of the organic acid increases, SO32- oxidation inhibition also increases. Accordingly, the denitrification rate of the slurries with added organic acid was in the order of PS < AS < FS. SO32- oxidation inhibition by the ethanolamine additives increased with the number of 2-hydroxyethyl. The denitrification rate within 50 min of reaction was in the order of MS < TS < DS, which is attributed to the basicity and SO32- oxidation inhibition by ethanolamine. The denitrification rate after 50 min of the reaction was in the order of MS 32- oxidation inhibition and degradation due to the CO2 absorption rate. [ABSTRACT FROM AUTHOR]

Seawater electrolysis for the production of fuels and chemicals involved in onshore and offshore plants powered by renewable energies offers a promising avenue and unique advantages for energy and environmental sustainability. Nevertheless, seawater electrolysis presents long-term challenges and issues, such as complex composition, potential side reactions, deposition of and poisoning by microorganisms and metal ions, as well as corrosion, thus hindering the rapid development of seawater electrolysis technology. This review focuses on the production of value-added fuels (hydrogen and beyond) and fine chemicals through seawater electrolysis, as a promising step towards sustainable energy development and carbon neutrality. The principle of seawater electrolysis and related challenges are first introduced, and the redox reaction mechanisms of fuels and chemicals are summarized. Strategies for operating anodes and cathodes including the development and application of chloride- and impurity-resistant electrocatalysts/membranes are reviewed. We comprehensively summarize the production of fuels and chemicals (hydrogen, carbon monoxide, sulfur, ammonia, etc.) at the cathode and anode via seawater electrolysis, and propose other potential strategies for co-producing fine chemicals, even sophisticated and electronic chemicals. Seawater electrolysis can drive the oxidation and upgrading of industrial pollutants or natural organics into value-added chemicals or degrade them into harmless substances, which would be meaningful for environmental protection. Finally, the perspective and prospects are outlined to address the challenges and expand the application of seawater electrolysis. [ABSTRACT FROM AUTHOR]

Manganese dioxide is a promising adsorbent which can be used to remove SO2 from diesel exhaust gases through dry flue gas desulfurization. In addition, MnO2 is active in moderate temperatures and produces manganese sulfate as a valuable byproduct. Therefore, obtaining kinetic parameters of this reaction is important in process design of emitted SO2 removal in various industrial units. We used the random pore model to investigate the kinetics of this non-catalytic gas–solid reaction for the first time. To obtain the degree of the reaction; the reaction rate constant; activation energy; and diffusion coefficient of SO2 in the product layer (DP), several experiments were conducted using isothermal thermogravimetry. Operating conditions of experiments were between 300 and 500 °C and SO2 concentrations between 0.1 and 0.8 vol%. It was confirmed that the reaction follows a first-order model, and activation energy was obtained to be 84.8 kJ mol−1. The diffusion of gas inside the product layer was considered to be a function of solid conversion and temperature and its parameters were estimated. The model results were compared with experimental at data various operating conditions. The results of random pore model matched very well with experimental conversion-time data with an average absolute relative deviation of about 2.36%. [ABSTRACT FROM AUTHOR]

Soybean straw (SS) enriched nitrogen-containing functional groups was used as a raw material to prepare biochar by combining CO2 and ultraviolet (UV) modification, which had high adsorption performance on SO2 and dichloromethane (DCM). The response surface methodology (RSM) was used to investigate the effects of retention time, flow rate of CO2, and activation temperature on the adsorption performance of biochar. On the basis of this, further UV modification was carried out, and the dynamic adsorption curves were fitted by using the Yoon-Nelson and Thomas models. The results showed that the optimal activation condition for preparing the desulfurized biochar was activation temperature of 788 ℃, CO2 flow rate of 400 ml/min, retention time of 57 min, UV modification temperature of 100 ℃, and time of 12 h, while that of the DCM removal biochar was activation temperature of 783 ℃, CO2 flow rate of 550 ml/min, retention time of 47 min, UV modification temperature of 200 ℃, and time of 12 h, and the adsorption values of SO2 and DCM at this time were 100.181 mg/g and 75.598 mg/g, respectively. Compared with the pyrolysis carbon (PC), the modified biochar had larger specific surface area, richer pores, and better adsorption performance. [ABSTRACT FROM AUTHOR]

We report a mechanistic investigation of an aromatic dithioimide (2SS) displaying puzzling yet efficient photochemistry in ether solvents. Perplexingly, 2SS dissolved in ether solvents in a sealed and degassed vial was photochemically converted to the corresponding diimide (2OO), as determined by 1H NMR following product extraction. With no external sources of oxygen in the sample, could the oxygen in 2OO be from the ether itself? To study this unprecedented proposition, we attempt to uncover the ether's involvement in this reaction. As seen by laser‐flash photolysis, 2SS appears to first react with the solvent from its singlet excited state. Following the reaction by NMR under rigorously oxygen‐ and water‐free conditions led to the identification of a photoreductive pathway that quantitatively transformed one thione into a methylene to yield 2SH2. Subsequent oxidation of 2SH2 or irradiation of 2SS under air proved that molecular oxygen was indeed necessary to observe an oxidative pathway leading to 2OO, ruling out the initially proposed involvement of an ether oxygen. An explanation of 2SS desulfurization was further revealed through the study of solvent by‐products by GC‐MS analysis. Supported by DFT calculations, a mechanism is proposed to involve a chain reaction initiated by photochemically generated ether radical. [ABSTRACT FROM AUTHOR]

A study was carried out on the effect of the nature of the support, composition of the active phase, and heat treatment conditions on the activity of trimetallic Ni‑Co‑Mo catalysts in the hydrotreating of a mixed diesel fraction. Temperature‑programmed desorption was used to show the effect of the amount and strength of the acid sites of the support on the activity of catalysts with the same elemental composition. We established the nickel‑to‑cobalt as well as phosphorus‑to‑molybdenum ratios in these trimetallic hydrotreating catalysts corresponding to the greatest desulfurization and minimum formation of polycyclic aromatic hydrocarbons in the hydrogenate. [ABSTRACT FROM AUTHOR]

The desulfurization of carbons modified with SO2 was studied as a dispersion in boiling cyclohexane (81°C) using activated carbon (mAC) and graphene oxide (mGO), modified by SO2. The steady‐state species in the carbon matrix after the catalytic reduction of SO2 was considered a trisulfane. For mAC, there was a burst of a sulfur species identified as S2 by UV spectrum with a maximum at 217 nm (εM at 217 nm = 2.56 × 103) that showed a second‐order decay of absorbance with kS2 = 47.29 M‐1·sec‐1 (ΔG354‡= 18.1 kcal·mol‐1). The product was postulated to be S4. No other consecutive reaction was observed because of the possible adsorption of S4 in the carbon matrix. The desulfurization of mGO was shown by XPS and the kinetics were a second‐order decay up to 16 min (kS2= 18.41 M‐1·sec‐1; ΔG354‡= 18.8 kcal·mol‐1) followed by a second‐order increase of absorbance with kS4 = 3.84 M‐1·sec‐1 (ΔG354‡= 19.9), where the product showed a double maximum at 260‐285 nm typical of S8. These results are consistent with a mechanism of consecutive thermodynamically favorable dimerizations of S2 and S4 and with the desulfurization mechanism that has been previously postulated. [ABSTRACT FROM AUTHOR]

This study investigated a new method for controlling the emission of fine particles through heterogeneous condensation. Specifically, the research focuses on the application of single-tower double-cycle desulfurization technology in the wet flue gas desulfurization process. The establishment of a supersaturation environment necessary for heterogeneous condensation was achieved by reducing the temperature of desulfurization slurry in the oxidation zone. Numerical simulations were used to study the distribution of the supersaturation degree and fluid dynamics characteristics in the desulfurization tower after the cooling of desulfurization slurry. Furthermore, the impact of single-tower double-cycle technology on the removal efficiency of fine particles was examined. The results of the numerical simulations indicate that cooling the desulfurization slurry in the absorption zone could establish a supersaturated vapor environment, with the supersaturation degree and region increasing as the slurry temperature decreases. Under typical operating conditions, a temperature drop of approximately 8~10 °C was found to be most suitable for the desulfurization slurry. Moreover, lowering the temperature of the desulfurization slurry in the absorption zone increases the supersaturation degree from 0.93 to 1.85. Additionally, the use of single-tower double-cycle desulfurization technology is shown to significantly enhance the removal efficiency of fine particles, particularly those within the particle size range of 0.1~1 μm. Ultimately, this method could increase the removal efficiency of fine particles from 39.9% to 57.9%. [ABSTRACT FROM AUTHOR]

Coal is still a great source of energy, but its high sulfur content causes environmental pollution and problems in its processing. This study used a method of combined oxidation and alkali leaching to desulfurize low-grade, high-sulfur Lakhra coal at different ranges of temperature, alkali concentration, leaching time, partial pressure of oxygen, and agitation speed. The optimum values for the leaching reaction were observed to be an alkali (NaOH) concentration of 0.8 mM, a leaching time of 1.5 h, an oxygen partial pressure of 150 psi, and an agitation speed of 800 rpm. The ash content of the coal initially increased at higher values of reaction time and temperature, and then became saturated at a certain peak. The raw coal was characterized for ultimate and proximate analysis, and the product was characterized for ash content and total sulfur content. [ABSTRACT FROM AUTHOR]

Marine bacteria contribute substantially to cycle macroalgae polysaccharides in marine environments. Carrageenans are the primary cell wall polysaccharides of red macroalgae. The carrageenan catabolism mechanism and pathways are still largely unclear. Pseudoalteromonas is a representative bacterial genus that can utilize carrageenan. We previously isolated the strain Pseudoalteromonas haloplanktis LL1 that could grow on ι-carrageenan but produce no ι-carrageenase. Here, through a combination of bioinformatic, biochemical, and genetic analyses, we determined that P. haloplanktis LL1 processed a desulfurization-depolymerization sequential pathway for ι-carrageenan utilization, which was initiated by key sulfatases PhSulf1 and PhSulf2. PhSulf2 acted as an endo/exo-G4S (4-O-sulfation-ß-D-galactopyranose) sulfatase, while PhSulf1 was identified as a novel endo-DA2S sulfatase that could function extracellularly. Because of the unique activity of PhSulf1 toward ι-carrageenan rather than oligosaccharides, P. haloplanktis LL1 was considered to have a distinct ι-carrageenan catabolic pathway compared to other known ι-carrageenan-degrading bacteria, which mainly employ multifunctional G4S sulfatases and exo-DA2S (2-O-sulfation-3,6-anhydro-a-D-galactopyranose) sulfatase for sulfate removal. Furthermore, we detected widespread occurrence of PhSulf1-encoding gene homologs in the global ocean, indicating the prevalence of such endo-acting DA2S sulfatases as well as the related ι-carrageenan catabolism pathway. This research provides valuable insights into the enzymatic processes involved in carrageenan catabolism within marine ecological systems. [ABSTRACT FROM AUTHOR]

Aiming at the problems of large lag and inertia in the PH control system of gypsum wet desulfurization in thermal power units, this paper proposes a cascade multi-step feed forward predictive control strategy based on proportional integral derivative (PID). Firstly, the paper establishes mechanism model through the transfer function of PH value influence factor to ensure a strong correlation between the control system parameters and the PH value; Secondly, based on the traditional PID control strategy, the paper introduces cascade and multi-step feed forward control mechanisms to solve the strong inertia of the control system; Then, the three-step predictive value of SO2 content in raw flue gas based on long short term memory network (LSTM) is introduced as the feed forward value, so as to better eliminate system lag characteristics and track the PH setting value; Finally, the simulation experiment is carried out using the desulfurization data of the plant. The simulation results show that, compared with the traditional PID and cascade PID control strategies, the control strategy proposed in this paper achieves more accurate and stable control of the PH value of desulfurization slurry in thermal power units, and improve the desulfurization efficiency. [ABSTRACT FROM AUTHOR]

According to international standards, motor fuels require limits on the content of sulfur, benzene, aromatic and olefinic hydrocarbons. Achieving these standards requires the development of new, active, and selective catalysts alongside advancement in technologies for deep hydrotreating and hydroprocessing. Therefore, this study aimed to investigate tetradecane and diesel oil fraction hydroprocessing using modified zeolite-based Ni(Co)-Mo(W)/Al2O3-ZSM-5 catalysts under varying processing conditions. The novelty is attributed to the synthesis of new catalysts based on ZSM-5 type zeolite, modified with metals Ni(Co)-Mo(W) and active additives of rare earth metals and phosphorus. The results showed that after hydrotreating diesel oil fraction on KT-3 catalyst, the pour point and sulfur level decreased from -27 to -57°C and 0.141 to 0.059% respectively, while the yield of the liquid phase was 92.2%. The lowest residual sulfur content (0.005%) was observed on KT-4 catalyst at 400°C. Based on electron microscopic examinations, modified zeolite-based catalysts were distributed in a highly dispersed manner, and the metal components in the active phase were primarily in the oxidized state, generating associate clusters on the surface. The dispersion, structure, and state were influenced by the characteristics of catalyst components. In conclusion, modified zeolite-based catalysts had multifunctional properties, facilitating hydrocracking, hydroisomerization, hydrodesulfurization, and dehydrogenation reactions concurrently. [ABSTRACT FROM AUTHOR]

The paper summarizes the results of numerous works performed by the employees of the Pobuzky Ferronickel Plant, the Department of Electrometallurgy of the USU of Science and Technology (Dnipro), RPC "Technosplavy" under the leadership of Mykhailo Hasyk, academician of NASU. A technology of low iron recovery has been implemented at the plant, which allows producing high-percentage black ferronickel, containing 30-50 % Ni, and almost hundredth fractions of carbon and silicon, directly in electric furnaces. The thermodynamic features of out-of-furnace ladle desulfurization of ferronickel with soda are considered. A complex technology has been developed and implemented, which involves mixing black ferronickel with a reduced silicon and carbon content (up to 0.01 %) and a high nickel content (over 50 %) produced in one furnace with an alloy from another furnace with a low nickel concentration (10-17 %) and a high concentration of silicon and carbon, which are so necessary for desulfurization with soda in a ladle. The developed and proposed technological schemes for the enrichment of electric furnace slags using the "wet" technology and refining slags using the "dry" technology make it possible to recycle about 1,200 tons of nickel per year, or to extract 31.6 % and 94.65 % of nickel from the slags, respectively. [ABSTRACT FROM AUTHOR]

Experiments were carried out in Si-killed high carbon steels with an innovative and cost effective approach, coke dust as a slag de-oxidation agent to reduce reducible oxides quantity and also its activity in the slag to improve desulfurization efficiency. The flux addition practice was also modified by increasing lime addition compared to synthetic slag, in order to increase the activity of CaO throughout the LF refining process. Various parameters such as the amount of carryover slag, melting point, electrical conductivity, viscosity, activity of FeO, CaO of ladle slag were calculated and its effect on desulfurization efficiency was studied in detail. Finally, an optimized slag composition was suggested using an error function. Industrial trials demonstrated a reduction in reducible oxide content from 5 to 1.5% and the maintenance of an increased CaO activity throughout the refining process improved desulfurization efficiency from 38% to greater than 50%. [ABSTRACT FROM AUTHOR]

Removal of sulfur compounds from transportation fuels is a requirement in the worldwide effort to reduce emissions from transportation fuels. Refineries use the hydrodesulfurisation (HDS) process to reduce sulfur compounds in fuels. However, the HDS process requires high hydrogen pressure and temperature, making it costly. An alternative to the HDS process is oxidative desulfurisation via solvent extraction, which requires low-temperature operating conditions. In this regard, deep eutectic solvents (DESs) are attractive for researchers to desulfurise transportation fuels via solvent extraction due to their low-cost. In our study, DESs were synthesised using phenylacetic acid (PAA) and salicylic acid (SAA) as hydrogen bond acceptors (HBAs) and tetraethylene glycol (TTEG) as hydrogen bond donor (HBD) in the mole ratio of 1:2. DESs were characterised by using Fourier transform infrared (FTIR) spectroscopy. Physicochemical properties of DESs, such as density, viscosity and refractive index, were also measured. The synthesised DESs were used to extract organosulfur compounds from model fuel and actual diesel. An oxidation study was carried out for model fuel and diesel, followed by solvent extraction using these synthesised DESs. The extraction efficiency for PAA/TTEG(1:2) and SAA/TTEG(1:2) was achieved as 50.16% and 38.89% for model fuel at a temperature of 30°C using a solvent to feed ratio of 1.0 while for diesel, it was 38% and 37%. However, it increased to 77%, 68% and 54%, 73%, respectively, for PAA/TTEG(1:2) and SAA/TTEG(1:2) when the feedstocks were oxidised. These results showed better extraction performance of DES PAA/TTEG(1:2) than that of SAA/TTEG(1:2) at low temperature 30°C using combined extractive catalytic oxidative desulfurisation. Hence, the DES synthesised using SAA and TTEG in the molar ratio of 1:2 works better as an extraction solvent for removing organic sulfur compounds from fuels at low temperatures. [ABSTRACT FROM AUTHOR]

Sulphur compounds and mercaptans in gas condensate cause corrosion problems, poison catalysts in catalytic processes, and have adverse environmental impact through SOx emission upon combustion. Therefore, it is essential to remove sulphur and mercaptan from gas condensate to standard levels. In this study, the oxidative desulphurization (ODS) process in the presence of a cobalt phthalocyanine sulfonamide‐based catalyst was investigated. The homogeneous catalyst containing 23 wt.% active material was used and optimum operating conditions of temperature, volume ratio of caustic to gas condensate, caustic concentration, and solvent amount were determined to decrease sulphur content to less than 500 ppm and mercaptan to less than 200 ppm. The catalyst consumption in all experiments was kept constant at a minimum level (0.01 g/400 mL gas condensate). Results showed that this catalyst improved the reaction rate in the lower temperature and lower caustic to feed ratio and lower caustic concentration. The maximum sulphur removal was obtained at 5°C and 4 vol.% of caustic to gas condensate ratio at 16.7 wt.% of caustic concentration. Moreover, this catalyst improved sulphur removal from the gas condensate to about 5% compared to caustic sweeting without catalyst. Sulphur compounds had higher solubility in acetone rather than methanol, and sulphur removal by acetone was 96% while it was 91% for methanol. Finally, the economical and acceptable solvent for sulfoxides removal was methanol with 5% volume fraction. [ABSTRACT FROM AUTHOR]