Application In Desulfurization Research Articles

Geoenvironmental characterization of orebody variability for application of environmental desulfurization for acid mine drainage risk prevention

Geoenvironmental characterization of orebody variability for application of environmental desulfurization for acid mine drainage risk prevention

Capture of Sulfur Dioxide in Ship Exhaust Gas by Tertiary Amine Absorbents

AbstractSulfur dioxide (SO2) emissions from ship exhausts pose serious health and environmental concerns. Herein, the SO2 absorption and desorption characteristics of tertiary amines with different functional groups were explored under simulated ship exhaust gas conditions. Tertiary amines with electron‐donating groups had superior absorption performance to those with electron‐withdrawing groups, and highly polar absorbents exhibited enhanced SO2 absorption loading. Dimethylaniline (DMA) showed excellent desorption performance, outperforming other absorbents (amino acids, ionic liquids, and deep eutectic solvents) in terms of cyclic capacity. Thus, tertiary amines, especially DMA, can be potentially used for the prevention of SO2 emissions from ship exhausts and other desulfurization applications.

Ionic Liquids as Green and Efficient Desulfurization Media Aiming at Clean Fuel.

With increasingly stringent emission limits on sulfur and sulfur-containing substances, the reduction and removal of sulfur compounds from fuels has become an urgent task. Emissions of sulfur-containing compounds pose a significant threat to the environment and human health. Ionic liquids (ILs) have attracted much attention in recent years as green solvents and functional materials, and their unique properties make them useful alternatives to conventional desulfurization organic solvents. This paper reviews the advantages and disadvantages of traditional desulfurization technologies such as hydrodesulfurization, oxidative desulfurization, biological desulfurization, adsorptive desulfurization, extractive desulfurization, etc. It focuses on the synthesis of ionic liquids and their applications in oxidative desulfurization, extractive desulfurization, extractive oxidative desulfurization, and catalytic oxidative desulfurization, and it analyzes the problems of ionic liquids that need to be solved urgently in desulfurization, looking forward to the development of sulfuric compounds as a kind of new and emerging green solvent in the field of desulfurization.

Environmental sustainability of closed-loop regeneration of NaHCO3 in CO2 utilization-driven desulfurization ash: From the perspective of integrated hybrid life cycle assessment

The closed-loop regeneration of NaHCO3 by treating sodium-based desulfurization ash (SDA) using CO2 in flue gas and ammonia by-products demonstrates an attractive perspective of low-cost sodium-based dry desulfurization (SDD) application. To push generation reuse of desulfurization ash into more practices, taking the application in coking plants as a case, this study first compares the environmental and economic performance of four scenarios of flue gas desulfurization (FGD) and desulfurization ash disposal by integrated hybrid life cycle assessment (IHLCA) with life cycle costing. Compared with process-based LCA, IHLCA captures more environmental impacts through the economic input-output (EIO) system, especially 36.40–67.89% of terrestrial ecotoxicity comes from the EIO system. Based on evaluation results of four scenarios, among the ten environmental impact categories (excluding photochemical oxidation), the SDD scenario with NaHCO3 regeneration by CO2 and ammonia (S2) is not only the most environmentally friendly route, but also has the lowest total hourly operating cost. These are mainly due to the offsetting effect of by-products replacing traditional chemicals on the total impact and avoiding landfill and raw material transportation. Furthermore, sensitivity analysis also shows that when technical parameters change, the environmental and economic performance of S2 still remains the best, except for the case when the NaHCO3 regeneration rate is 60%. The findings will be valuable for the selection and optimization of FGD in coking plants, incineration plants, and others.

Mass transfer enhancement for simultaneous desulfurization and denitrification by a venturi reactor

Interphase mass transfer is acknowledged as the rate-limiting step of simultaneous desulfurization and denitrification by wet oxidation. For this issue, this study established a venturi reactor to facilitate interphase mass transfer between flue gas and absorbent (NaClO2 solution), and to improve the efficiency of simultaneous desulfurization and denitrification. The effects of flow rate of jet, NaClO2 concentration, initial pH of solution, SO2 and NO volume concentration on the efficiency of desulfurization and denitrification were investigated. The results showed that SO2 can be completely removed at all experimental conditions. The denitrification efficiency decreased as jet flow rate increased from 8.38 L/ min to 12.87 L/min. The denitrification efficiency and overall mass transfer coefficient increased as the NaClO2 concentration increased from 0.01 wt% to 0.025 wt%. When the pH of the absorbent decreased from 9 to 3, the denitrification efficiency was improved significantly. An increasing SO2 volume concentration promoted NO removal efficiency, while SO2 and NO competed to inhibit denitrification at NaClO2 deficiency. The denitrification efficiency firstly increased and then decreased, with an increasing NO volume concentration from 500 to 1700 ppm. This study provides an important theoretical basis for the industrial application of simultaneous desulfurization and denitrification in venturi reactors.

Controllable Synthesis of Titanium Silicon Molecular Zeolite Nanosheet with Short b-Axis Thickness and Application in Oxidative Desulfurization.

Titanium silicon molecular zeolite (TS-1) plays an important role in catalytic reactions due to its unique nanostructure. The straight channel on TS-1 was parallel to the orientation of the short b-axis and directly exposed to the aperture of the 10-member ring with a diameter of 0.54 nm × 0.56 nm. This structure could effectively reduce the diffuse restriction of bulk organic compounds during the oxidative desulfurization process. As a kind of cationic polymer electrolyte, polydimethyldiallyl ammonium chloride (PDDA) contains continuous [C8H16N+Cl-] chain segments, in which the Cl- could function as an effective structure-directing agent in the synthesis of nanomaterials. The chain of PDDA could adequately interact with the [0 1 0] plane in the preparation process of zeolite, and then the TS-1 nanosheet with short b-axis thickness (6 nm) could be obtained. The pore structure of the TS-1 nanosheet is controlled by regulating the content of PDDA. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), N2 physical adsorption analysis, infrared absorption spectrum and ultraviolet-visible spectrum were used to determine the TS-1. The thinner nanosheets exhibit excellent catalytic performance in oxidative desulfurization of dibenzothiophene (DBT), in which the removal rate could remain at 100% after three recycles. Here, the TS-1 nanosheet with short b-axis thickness has a promising future in catalytic reactions.

Synthesis and utilization of polyol-modified high specific surface area Ca(OH)2: an investigation.

Calcium hydroxide (Ca(OH)2) finds widespread use in the petrochemical industry, particularly in flue gas desulfurization applications. However, its conventional usage is limited by its inherently low specific surface area, hampering its efficiency. To address this limitation, this study aims to develop a simple and industrially scalable preparation process for Ca(OH)2 with a high specific surface area, thereby enhancing its effectiveness in various applications. This study aimed to develop a preparation process for making Ca(OH)2 with a high specific surface area, suitable for industry and easy to make. Ca(OH)2 with a specific surface area of 41.555 m2/g was successfully synthesized by incorporating polyols during lime digestion. The prepared high specific surface area Ca(OH)2 is more than five times the specific surface area of ordinary Ca(OH)2. Incorporation of polyols within the lime digestion process induces a reduction in both Ca(OH)2 grain size and particle dimensions, concurrently amplifying the specific surface area and optimizing mass transfer efficiency. Specifically, the desulfurization breakthrough time for Ca(OH)2 subject to a 15% triethanolamine modification was notably extended to 879s, surpassing the desulfurization breakthrough time of unaltered Ca(OH)2 by more than tenfold. Moreover, the modified Ca(OH)2 exhibited remarkable efficacy in neutralizing acidic wastewater. A new approach for the preparation of high-performance Ca(OH)2 is proposed in this study, which could facilitate the industrial production of Ca(OH)2 with high specific surface area.

Diatomite supported bagel-like hydroxylated mesoporous carbon nitride towards the adsorption desulfurization application

The carbon nitride (g-C3N4) nanosheets was apt to occur the donor-acceptor (D-A) interaction with the sulfides via the influence of the electronic structure of C atoms in the ring. Accordingly, we implemented an environmental- friendly approach to raise the electropositivity of the C atoms of N atoms in the ring of g-C3N4 through the hydroxylation treatment of hydrogen peroxide(H2O2), and afterwards constructed a bagel-like morphology composite ((HO)x/g-C3N4@DE) by virtue of the calcined combination of hydroxylated mesoporous g-C3N4 and diatomite (DE). The characterization results showed that the substantial mesoporous structure was produced in the formation of (HO)x/g-C3N4@DE composite. The adsorption desulfurization experiments showed that the bagel-like hydroxylated mesoporous (HO)x/g-C3N4@DE had the optimum adsorption capacity of up to 42.2 mg/g for thiophene (TH) and 30.8 mg/g for benzothiophene (BT), respectively. Moreover, the adsorption capacities of the hydroxylated mesoporous (HO)x/g-C3N4@DE were dramatically higher than the individual (HO)x/g-C3N4 (18.92 mg/g for TH and 15.64 mg/g for BT), suggesting that the occurrence of the secondary stacked mesopores in the formation of the (HO)x/g-C3N4 on the surface and macro-porous structure of DE affected the adsorption capacity. Lastly, the adsorption mechanism of the hydroxylated mesoporous (HO)x/g-C3N4@DE was proposed.

Physical mixing of K2CO3/Al2O3 and poly(divinylbenzene) to promote COS removal from blast furnace gas with high humidity at low temperature

Blast furnace gas (BFG) is a high emission and widely used secondary energy source. However, the presence of sulfide in BFG leads to environment pollution. Carbonyl sulfide (COS) is the main (70 %) sulfide in BFG. Catalytic hydrolysis is an important method for COS removal, but the excessive water contained in BFG can significantly inhibit the performance of hydrolysis catalyst. In present work, K2CO3 was loaded on Al2O3 support using wet impregnation method to improve its hydrolysis efficiency. Moreover, a physical mixing method was employed to combine K2CO3/Al2O3 with hydrophobic poly(divinylbenzene) (PDVB) to improve the water resistance of K2CO3/Al2O3. It was found that a simple physical mixture of PDVB with K2CO3/Al2O3 could modulate the local environment of K2CO3/Al2O3, shifting the water-sorption equilibrium on the surface of the catalyst and releasing partial water-covered catalyst surface for hydrolysis. Under the reaction temperature of 90 °C and water vapor content of 34.4 g/m3, the hydrolysis efficiency of COS increased by ∼22.5 % via mixing K2CO3/Al2O3 with PDVB. This approach demonstrates the potential to enhance the hydrolysis efficiency of catalyst for COS removal from BFG with high humidity at low temperature, which is crucial for the practical application of desulfurization of BFG.

The Green Preparation of Mesoporous WO3/SiO2 and Its Application in Oxidative Desulfurization

Recently, supported WO3-based catalysts have been widely used in oxidative desulfurization (ODS) due to their advantages of easy separation, high activity, and being environment-friendly. In this work, supported mesoporous WO3/SiO2 catalysts have been prepared using an incipient-wetness impregnation method with agricultural waste rice husks as both a silicon source and mesoporous template, and phosphotungstic acid as a tungsten source. The effects of different calcination temperatures and WO3 loadings on the ODS performance of samples are studied, and the appropriate calcination temperature and WO3 loading are 923 K and 15.0 wt.%, respectively. The relevant characterization results show that, compared with pure WO3, the specific surface area and mesopore volume of WO3/SiO2 samples are greatly increased. Due to (a) high WO3 loading, (b) high specific surface area, and (c) nanoscale WO3 grains uniformly dispersed on the surface of the mesoporous SiO2 carrier, active sites of WO3/SiO2 catalysts are greatly increased, and their catalytic activities are improved. After the sixth and eighth runs in the ODS of dibenzothiophene and 4,6-dimethyldibenzothiophene, respectively, the WO3/SiO2 catalyst still maintains high catalytic activity (>99.0%) despite the presence of a partial loss of WO3. In addition, with the aid of the UV-Vis technique, the tungsten-peroxo species, the active intermediates in the ODS reaction catalyzed by the WO3/SiO2 catalyst, are captured. Finally, a possible mechanism for the ODS of bulky organic sulfides using the WO3/SiO2 catalyst is proposed.

Photocatalytic desulfurization of gas condensate using zinc diacetate and cadmium diacetate liquid catalysts

This inquiry studied the application of photocatalytic desulfurization as an effective method for removing sulfur-containing organic compounds from gas condensate extracted from oil wells. To this end, cadmium diacetate and zinc diacetate compounds were prepared as the liquid catalysts. Then their structures were confirmed and their properties were determined by common methods, including FTIR, NMR, and UV. Subsequently, their performances as catalysts were investigated by an optical technique for the desulfurization process. Accordingly, the study used a photoreactor equipped with a 250 W mercury ultraviolet lamp with a maximum wavelength of 365 nm, and investigated and optimized the effect of the ratios of the influencing parameters on the total sulfur removal efficiency. These included the ratios of fuel to photocatalyst, H2O2, and acetonitrile. Ratios of 1:2:3:2 and 1:3:2:1 (fuel: catalyst: oxidant: solvent) of zinc and cadmium diacetate led to 93.5 % and 87.1 % reduction of the total sulfur content, respectively, after 60 min since the exposure process. Also, under sunlight, the total sulfur removal was 67.0 % for the Zn diacetate and 42.0 % for Cd diacetate. Liquid diacetate photocatalysts were successfully recycled over five cycles with only a maximum of 10 % reduction in efficiency. The kinetics of the systems studied were evaluated under optimal conditions and it was found that both systems fit the pseudo-first order model with rate constants of 0.148 min−1 and 0.098 min−1, respectively. In the final step, some physicochemical properties of the desulfurized sample crucial in evaluation of fuel quality were determined under optimal conditions and compared with the properties of the original sample. The results indicated that the liquid photocatalysts used in the experiment increased the quality of the fuel by changing its important indicators by reducing its freezing point in addition to increasing its cetane number.

A green method for the preparation of nitrogen-doped mesoporous carbon and its application in adsorptive desulfurization

Nitrogen-doped porous carbons (NMCs) were prepared using a green method.

The single metal atom (Ni, Pd, Pt) anchored on defective hexagonal boron nitride for oxidative desulfurization.

Single-atom catalysts (SACs) have attracted great attention for various chemical reactions because of their strong activity, high metal utilization ratio, and low cost. Here, by using the density functional theory (DFT) method, the stability of a single VIII-group metal atom (M = Ni, Pd, Pt) anchored on the defective hexagonal boron nitride (h-BN) sheet and its possible application in oxidative desulfurization (ODS) are investigated. Calculations show that the stability of the single M atom embedded in the h-BN surface with B and N vacancies is strikingly enhanced compared to that on the perfect h-BN surface. The catalytic activities of the defective h-BN-supported single metal atom are further studied by the activation of molecular oxygen and subsequent oxidation of dibenzothiophene (DBT). O2 is activated to the super-oxo state with large interaction energies on three M/VN surfaces. However, among the three M/VB surfaces, only Pt/VB performs efficient activation of O2. The oxidation of DBT proceeds in two steps; the rate-determining step is the initial step, in which activated O2 oxidizes DBT to produce sulfoxide. By comparing the energy barrier in the first reaction step, both Ni/VN and Pt/VB are revealed as promising candidates for the ODS reaction.

Robust interaction of ZnO and TiO2 nanoparticles with layered graphitic carbon nitride for enhanced photocatalytic oxidative desulfurization of fuel oil: mechanism, performance and stability.

Sulfur compounds in fuel such as thiophene, benzothiophene and dibenzothiophene are the primary source of SO x emissions, leading to environmental pollution and acid rain. In this study, we synthesized a layered oxygen-doped graphitic carbon nitride (OCN) structure and integrated ZnO and TiO2 nanoparticles onto the OCN surface through a microwave-assisted sol-gel method. The X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) results confirmed a robust interaction between the ZnO and TiO2 nanoparticles and the oxygen-doped g-C3N4 (OCN) surface, as indicated by the formation of C-N-Ti and C-O-Ti bonds. This interaction notably improved the optoelectronic properties of the ZnO-TiO2/OCN composite, yielding increased visible light absorption, reduced charge recombination rate, and enhanced separation and transfer of photogenerated electron-hole pairs. The oxygen doping into the CN network could alter the band structure and expand the absorption range of visible light. The ZnO-TiO2/OCN photocatalyst demonstrated remarkable desulfurization capabilities, converting 99.19% of dibenzothiophene (DBT) to dibenzothiophene sulfone (DBT-O2) at 25 °C, and eliminating 92.13% of DBT from real-world fuel oil samples. We conducted in-depth analysis of the factors impacting the redox process of DBT, including the ZnO ratio, initial DBT concentration, catalyst dosage, stability, and O/S molar ratio. Radical trapping experiments established that ˙O2 -, ˙OH and h+ radicals significantly influence the reaction rate. The obtained results indicated that the ZnO-TiO2/OCN photocatalyst represents a promising tool for future fuel oil desulfurization applications.

Carbon nanosheets composited with MgO/CaO prepared by one-step co-pyrolysis strategy for efficient H2S oxidation at room temperature

Carbon nanosheets have promising application in desulfurization but are challenged by high cost and cumbersome preparation process. In this work, carbon nanosheets composited with CaO and MgO (MgxCay/C) were fabricated by one-step co-pyrolysis of magnesium gluconate and calcium gluconate. This carbon nanosheets material enables the efficient room temperature H2S oxidation in a moist atmosphere. The characterization results indicate that this co-pyrolysis strategy produces defect-rich carbon nanosheets with uniformly distributed oxides nanoparticles for the adsorption and activation of H2S as well as O2. Significantly, numerous nanoholes with a size of 5–20 nm are obtained on the carbon nanosheets, which serve as S storage space to form S polymer resistant to further oxidation, inhibiting the formation of H2SO4 and its subsequent consumption of active components. As a result, the Mg1Ca9/C shows a tremendous H2S capacity of 858.5 mg/gcat.. In addition, the processes of H2S oxidation over the MgxCay/C and its deactivation are also detailly illustrated. This study contributes to providing a low-cost and facile preparation approach for carbon nanosheets in desulfurization and other diverse applications.

Molecular modeling of 1-butyl-3-methylimidazolium based ionic liquids for potential applications in the desulfurization of diesel fuel

The sulfur compounds in diesel fuel produce harmful environmental pollutants during combustion. Hydrodesulfurization (HDS) is the most common technique to reduce the sulfur content of diesel fuel but cannot effectively remove aromatic sulfur compounds to produce ultra-low-sulfur diesel. Ionic liquids (ILs) show potential as alternative solvents for extractive desulfurization to be implemented after a conventional HDS process, but the mechanism is not well understood. This work focuses on using a combination of molecular simulation free energy calculations and detailed structural analysis to better understand the molecular-level interactions between dibenzothiophene and seven common imidazolium-based ILs. The free energy calculations suggest that the ILs interact differently with thiophene and dibenzothiophene. No specific interactions were observed between the anion and dibenzothiophene; varying the anion showed no remarkable differences in the observed interactions. It was determined that interactions between dibenzothiophene and the cation were more significant; π-π stacking between the imidazole ring and thiophene ring plus favorable electrostatic interactions between the alkyl chain and benzene rings were observed. The primary goal of this work is to use molecular simulations to complement current experimental research to identify suitable ILs for potential extractive desulfurization applications.

Mapping the knowledge domain of microbial desulfurization application in fuels and ores for sustainable industry.

Direct application of high-sulfur fuels and ores can cause environmental pollution (such as air pollution and acid rain) and, in serious cases, endanger human health and contribute to property damage. In the background of preserving the environment, microbial desulfurization technologies for high-sulfur fuels and ores are rapidly developed. This paper aims to reveal the progress of microbial desulfurization research on fuels and ores using bibliometric analysis. 910 publications on microbial desulfurization of fuels and ores from web core databases were collected in this work, spanning 39 years. Through 910 retrieved documents, collaborative networks of authors, institutions and countries were mapped by this work, the sources of highly cited articles and cited documents were statistically analyzed, and keyword development from different perspectives was discussed. The results of the study provide a reference for microbial desulfurization research and benefit environmental protection and energy green applications.

Ionic liquids based on metal halide complex salts and their applications in extractive desulfurization of liquid fuel: A review

In this review, different types of sulfur compounds (thiols, sulfides, benzothiophenes, etc.) present in liquid fuel can be conveted by combustion to sulphur dioxide, which is a prevailing source of environmental pollution, so many countries proposed standard S-content to lower than 10 ppm. Although, hydrocracking process produce low-sulfur content, but still needs more desulfurization, researches have done using many technologies, among that were: A: Adsorptive desulfurization (ADS), through adsorptive over such surfaces. B: Oxidative Desulfurization (ODS), using an oxidant agent to convert sulfure into form can be removed. C: Hydrodesulfurization process (HDS), which is most efficient than other methods to remove organo sulfur (aliphatic and aromatic). D: Bio desulfurization (BDS), employed microorganisms to remove sulfur atom from organic S-compounds and can be environmental friendly. E: Extractive desulfurization (EDS), is a prosses using solvent as liquid- liquid extraction. The above technologies faced some disadvenges such as nature of volatile molecular solvent coupled with limitation of loss solvent, difficult of extraction regeneration, environmental pollution and costly, as required industrial unit operation at high temperature and pressure beside the expensive of hydrogen gas and catalysts. Therefore, it has been a challenge research investigation to explore a new deep extractive desulfurization methods. Among these treatments was using ionic liquids (ILS) which composed of heterocyclic organic cation (imidazolium, pyridinium, etc.) and different inorganic anions my be applied to decrease temperature, non-toxic, chemical stability, environmental friendly as green solvent, so, (ILS) used for many applications and deep eutectic desulfurization among that. Recently, studies showed that metal contains ionic liquids for extractive sulphur removal have a high influence and ability for sulphur removal than metal free (ILS) , which may be a good solvent in separation and removal of aromatic sulphur from fuel. The Fe, Co, Ni, Zn, Cu, etc. metals halides were used with organic cation to form complexes salts. The mechanism was investigated that the metal (ILS) have almost good extraction ability explained by the complexation of metal moiety with sulfur compounds.

From Genes to Bioleaching: Unraveling Sulfur Metabolism in Acidithiobacillus Genus.

Sulfur oxidation stands as a pivotal process within the Earth's sulfur cycle, in which Acidithiobacillus species emerge as skillful sulfur-oxidizing bacteria. They are able to efficiently oxidize several reduced inorganic sulfur compounds (RISCs) under extreme conditions for their autotrophic growth. This unique characteristic has made these bacteria a useful tool in bioleaching and biological desulfurization applications. Extensive research has unraveled diverse sulfur metabolism pathways and their corresponding regulatory systems. The metabolic arsenal of the Acidithiobacillus genus includes oxidative enzymes such as: (i) elemental sulfur oxidation enzymes, like sulfur dioxygenase (SDO), sulfur oxygenase reductase (SOR), and heterodisulfide reductase (HDR-like system); (ii) enzymes involved in thiosulfate oxidation pathways, including the sulfur oxidation (Sox) system, tetrathionate hydrolase (TetH), and thiosulfate quinone oxidoreductase (TQO); (iii) sulfide oxidation enzymes, like sulfide:quinone oxidoreductase (SQR); and (iv) sulfite oxidation pathways, such as sulfite oxidase (SOX). This review summarizes the current state of the art of sulfur metabolic processes in Acidithiobacillus species, which are key players of industrial biomining processes. Furthermore, this manuscript highlights the existing challenges and barriers to further exploring the sulfur metabolism of this peculiar extremophilic genus.

3D printing of the multifunctional fixed-bed reactor and matched 3D-CeO2/ATP monolithic adsorbent for adsorption desulfurization

The construction of monolithic adsorbents can promote the potential industrial application for adsorption desulfurization of fuel. Herein, the 3D-CeO2/ATP monolithic adsorbents were successfully constructed through a 3D printing strategy, possessing superior adsorption desulfurization performance of more than 85 % sulfur removal under optimized adsorption reaction conditions at room temperature. Combined with the 3D-printed multifunctional fixed-bed reactor, the reaction process capable of adsorption-elution was designed for continuously realizing the deep adsorption of sulfide in fuel and the resource recovery of high-value sulfide products. The structure and physicochemical property of 3D-CeO2/ATP monolithic adsorbents were analyzed by series of characterizations, and the adsorption and elution mechanism were investigated in detail. The results reveal that the monolithic adsorbent with the internal staggered honeycomb structure was compared with that of the traditional in-line structure in terms of adsorption performance and computational fluid dynamics (CFD) fluid simulations, reflecting the advantages of 3D printing in structural forming to enhance mass transfer for promoting the adsorption process. Moreover, the 3D-printed monolithic adsorbents exhibit exceptional mechanical stability and good circulation performance, reaching the requirements for potential industrial application.