Sulfur Recovery Research Articles

Construction of Confined Bifunctional 2D Material for Efficient Sulfur Resource Recovery and Hg2+ Adsorption in Desulfurization.

Substantial energy penalty of valuable sulfate recovery restricts the efficiency of wet desulfurization and increases the risk of Hg0 reemission. Although the enhanced sulfite oxidation rate with cobalt-based materials can increase the energy efficiency, inactivation and poisoning of catalyst due to the competition of reactant must be addressed. Here we obtained a superwetting two-dimensional cobalt-nitrogen-doped carbon (2D Co-N-C) nanosheet featuring confined catalysis/adsorption sites for the energy-efficient sulfite oxidation and Hg2+ adsorption. The designed structure exhibits enhanced surface polarity, availability and short reactant diffusion path, thus enabling the significant catalytic TOF value of 0.085 s-1 and simultaneous mercury removal ability of 143.26 mg·g-1. The catalyst nanosheets present regenerating stabilities to improve cost-efficiency. By deployment of the Co-N-C catalysts, a marked reduction of heat penalty up to 69% can be achieved, which makes this catalytic pathway for sulfur resource recovery economically feasible in real industry scenario.

Oxygen Vacancy-Mediated Selective H2S Oxidation over Co-Doped LaFexCo1−xO3 Perovskite

Compared to the Claus process, selective H2S catalytic oxidation to sulfur is a promising reaction, as it is not subject to thermodynamic limitations and could theoretically achieve ~100% H2S conversion to sulfur. In this study, we investigated the effects of Co and Fe co-doping in ABO3 perovskite on H2S selective catalytic oxidation. A series of LaFexCo1−xO3 (x = 0, 0.2, 0.4, 0.6, 0.8, 1.0) perovskites were synthesized by the sol-gel method. Compared to LaFeO3 and LaCoO3, co-doped LaFexCo1−xO3 significantly improved the H2S conversion and sulfur selectivity at a lower reaction temperature. Nearly 100% sulfur yield was achieved on LaFe0.4Co0.6O3 under 220 °C with exceptional catalyst stability (above 95% sulfur yield after 77 h). The catalysts were characterized by XRD, BET, FTIR, XPS, and H2-TPR. The characterization results showed that the structure of LaFexCo1−xO3 changed from the rhombic phase of LaCoO3 to the cubic phase of LaFeO3 with Fe substitution. Doping with appropriate iron (x = 0.4) facilitates the reduction of Co ions in the catalyst, thereby promoting the H2S selective oxidation. This study demonstrates a promising approach for low-temperature H2S combustion with ~100% sulfur yield.

EVALUATION OF THE ELEMENTAL COMPOSITION OF ANTHEMIS TROTZKIANA CLAUS IN THE REGIONS OF WESTERN KAZAKHSTAN

The article presents the results of evaluation studies on the elemental composition of Anthemis trotzkiana Claus plants growing in the Aktobe region in Western Kazakhstan. All selected samples from three populations of a rare plant species for chemical composition were examined by atomic absorption spectroscopy. Evaluation studies of the elemental composition of the vegetative organs of A. trotzkiana have shown that extracts obtained from leaves, roots, and stems of plants can be a promising source of macro- and microelements for pharmacopoeial purposes. Endemism of the species A. trotzkiana, distributed locally in the regions of Western Kazakhstan, requires measures for the rational use of this species.

Rotten Eggs Revaluated: Ionic Liquids and Deep Eutectic Solvents for Removal and Utilization of Hydrogen Sulfide

Hydrogen sulfide (H2S) is highly toxic and one of the problematic impurities in industrial gas streams, calling for H2S removal down to single-digit ppm levels to protect health and environment, and not to harm to the downstream processes. Here, we discuss the recent developments and challenges of current H2S removal technologies. Furthermore, we present a comprehensive review of H2S removal in ionic liquids (ILs), IL-based solvents/adsorbents/membranes, and deep eutectic solvents (DESs) due to their unique advantages. We analyze theoretical studies to better understand the microscopic details behind H2S removal. We discuss new research on IL/DES-based H2S removal processes from an industrial perspective. Finally, we summarize the utilization of H2S in IL/DES-based systems for the recovery of sulfur and hydrogen, and synthesis of value-added chemicals. This review will provide both general and in-depth knowledge of the achievements, difficulties, and research priorities in developing novel ILs/DESs for efficient and sustainable H2S removal and utilization.

Enhanced sulfur recovery and sulfate reduction using single-chamber bioelectrochemical system

The aim of this study was to investigate the feasibility of sulfate removal and elemental sulfur (S0) recovery in the single-chamber bioelectrochemical system (S-BES). The performance of S-BES was compared with that of dual-chamber bioelectrochemical system (D-BES). The S-BES was constructed with graphite felt as the anode and graphite brush as the cathode. The D-BES was constructed with proton exchange membrane as the separator between anode and cathode chambers. With an applied voltage of 1.0 V and 1 g/L acetate as the substrate, the S-BES and D-BES were tested by feeding with 480 mg/L SO42− in the phosphate buffer. Results showed that the maximum current density of 37.6 ± 4.5 mA/m3 was reached in the S-BES, which was higher than that in the D-BES (i.e., 22.2 ± 2.6 mA/m3). The SO42− removal was much higher in the S-BES than in the D-BES (99.5% vs. 57.2%). In the effluent and the electrodes of S-BES, S0 was identified with Raman and X- Ray diffraction analyses. The S0 recovery on the anode was 13.7 times of that on the cathode of S-BES, indicating that S0 was mainly produced on the anode. The measured total S0 recovery reached 67.5% in the S-BES. High relative abundance of Desulfurella (47.1%) and Geobacter (26.1%) dominated the community in the anode biofilm of S-BES. The excellent performance of S-BES may be attributed to the neutral pH in the solution and the synergistic reaction between the anode and cathode. Results from this study should be useful to enhance the S-BES applications in treating wastewater containing sulfate.

Application of Wedge Flowmeter in Sulfur Recovery Unit

Application of Wedge Flowmeter in Sulfur Recovery Unit

The Mechanism of the Effect of Pre-Magnetized Butyl Xanthate on Chalcopyrite Flotation

In this work, we applied the technology of magnetic treatment to the flotation of chalcopyrite. The mechanism of the effect of pre-magnetized butyl xanthate on chalcopyrite flotation was studied using monomineral flotation tests, adsorption tests, conductivity tests, Fourier transform infrared spectroscopy (FTIR), etc. The monomineral flotation test results showed that, after the magnetization pretreatment of butyl xanthate solution, the chalcopyrite flotation recovery was increased by nearly two percentage points, and the dosage was reduced by 4–10 mg/L at the same recovery. The adsorption, FTIR, dissolved oxygen, and conductivity test results all showed that the magnetization pretreatment increased the dissolved oxygen content and promoted the oxidation of butyl xanthate to double xanthate with better selectivity to chalcopyrite. An electrochemical analysis showed that the magnetization pretreatment of butyl xanthate reduced the corrosion potential and corrosion current density of chalcopyrite surface and inhibited the self-corrosion process of chalcopyrite surface. The flotation test results of actual copper sulfide ore showed that pre-magnetized butyl xanthate could increase the copper recovery of copper concentrate by 3.06 percentage points and the sulfur recovery of sulfur concentrate by nearly 3 percentage points, and effectively reduce the mutual content of copper and sulfur concentrates.

Anoxic treatment for thiosulfate separation from formate containing dithionite industrial effluent and electrochemical sulfur recovery

The present work deals with utilization of formate present in the dithionite industrial effluent for thiosulfate separation and electrochemical sulfur recovery. In anoxic treatment, Pseudomonas aeruginosa and Proteus mirabilis were used for formate utilization and thiosulfate reduction. The organisms utilized sodium formate as a carbon source and thiosulfate as a terminal electron acceptor, it degraded the organic compounds fully present in the effluent. Thiosulfate got reduced to sulfide or hydrogen sulfide, where thiosulfate reduction was insignificant. Impact of iron surface on anoxic thiosulfate reduction was also investigated in the present study. An electrochemical two chambered membrane cell was used to recover sulfur from the biogenic sulfide electrolyte. Three different types of surface pattern (flattened, twisted and cylindrical) of Ti-TiO2/IrO2/RuO2 coated mesh anodes were used to comparing the sulfide to sulfur conversion process. Rotating cylindrical mesh electrode gave maximum sulfur recovery efficiency (96%) when compared to twisted (91%) and flattened (61%) electrodes. In this process, excess sodium hydroxide was also recovered at the catholyte during biogenic sulfide oxidation.

Simplified Structural Analysis and Design Procedures for Sulfur Recovery Units

AbstractThis paper presents cost-effective guidelines for practicing engineers to design, evaluate, or review the structural design of the sulfur recovery unit (SRU) used in refineries. Extensive e...

The recovery of sulfur as ZnS particles from sulfide-contained wastewater using fluidized bed homogeneous crystallization technology

Sulfide wastewater that is anthropogenically generated from industrial activities is highly corrosive, hazardous, and harms the natural ecosystem. This study uses a novel fluidized-bed homogeneous crystallization (FBHC) method to remove sulfide ions from an aqueous solution. Zinc is used as a precipitant to crystallize ZnS homogeneously in the FBHC reactor to reduce the sludge, which is commonly produced in a conventional chemical precipitation process. The optimal pH value, [Zn2+]0/[S2-]0 M ratio, sulfide cross-sectional surface loading (L, kg-S/m2.hr), and hydraulic retention time (HRT) for the system are established, to optimize the sulfur removal efficiency. The maximum crystallization ratio and the total removal efficiency for sulfur are 97.7% and 98.8%, respectively, at pH = 5.4, a [Zn2+]0/[S2-]0 M ratio of 1, a cross-sectional surface loading of 2.2 kg-S/m2.hr, and an HRT number of 6 with an initial sulfur concentration of 320 mg/L. The solid products are collected and identified as zinc sulfide (wurtzite) using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS).

Understanding of Correlation between Electronic Properties and Sulfur Tolerance of Pt-Based Catalysts for Hydrogen Oxidation.

Renewable power-derived green hydrogen distributed via natural gas networks is considered one of the viable routes to drive the decarbonization of transportation and distributed power generation, while a trace amount of sulfur impurities is one of the key factors that affect the durability and life cycle expense of proton-exchange membrane fuel cells (PEMFCs) for end users. Herein, we explore the underlying effect of sulfur resistance for Pt-based hydrogen oxidation reaction (HOR) electrocatalysts devoted to high-performance and durable PEMFCs. Two typical electrocatalysts, Pt/C with pure Pt nanoparticles (NPs) and PtCo/C with Pt3Co-alloy-core-Pt-skin NPs, were investigated to demonstrate the structure-property relation for Pt-based electrocatalysts. It was revealed that the PtCo/C demonstrated alleviated sulfur poisoning with the adsorption rate constant reduced by 21.7% compared with Pt/C, and the desorption of the adsorbed sulfur was also more favorable with Pt-S bond decomposition temperature lowered by approximately 25 °C. Characterization indicated that sulfur was predominantly adsorbed in the edge mode for PtCo/C, but in a comparable edge and bridge mode for Pt/C, which caused the strengthened Pt-S binding by the chelation effect for Pt/C. The lowered d-band center of surface Pt for PtCo/C, tuned by electron transfer from Co to Pt and Pt lattice strain, was also found responsible for the weakened Pt-S interaction. The recovery test based on electro-oxidation suggested that PtCo/C also outperformed Pt/C with faster and more thorough release of HOR active sites. The SO42- species derived from electro-oxidation of S2- was more apt to adsorb on Pt/C than PtCo/C because of its stronger affinity to SO42- caused by the higher d-band center of Pt. Therefore, it is clarified that adequate modification of the Pt d-band center, for example, negatively tuned for the state-of-the-art Pt/C, is crucial to improve the sulfur resistance and recovery capability for Pt-based electrocatalysts while reserving comparable HOR activity. In particular, the investigated PtCo/C electrocatalyst is a better choice over Pt/C for more durable PEMFC anodes.

Quantifying and Characterizing Sulfide Oxidation to Inform Operation of Electrochemical Sulfur Recovery from Wastewater

Quantifying and Characterizing Sulfide Oxidation to Inform Operation of Electrochemical Sulfur Recovery from Wastewater

A comprehensive thermodynamic analysis of an integrated solar enhanced oil recovery system for applications in heavy oil fields

In this work, we present an integrated energy system for solar enhanced oil recovery (SEOR) process accompanied with electricity generation, fresh water and elemental sulfur production. The system shows the possibilities of integrating solar energy in upstream and downstream oil industry applications while offering the same quality of service. Such studies are of great interest to the Gulf Cooperation Council (GCC) region where solar irradiance is high during the year and where an abundance of mature heavy oil reservoir is present. We harness the solar energy from the sun to produce high quality steam at elevated temperature by the means of concentrated solar power technology through solar towers. The steam is used in generating electricity that is used for artificial lift purpose in the production wells, and provides steam suitable for injection purposes in tertiary recovery phase for hydrocarbon reservoirs. The overall system is analyzed in terms of energy and exergy efficiencies and the effects of different operating system parameters are evaluated. The steam generator and the furnace have the highest exergy destruction rates at a relative percentage of 41.3% and 39%. The energy and exergy efficiencies for the Claus process is reported at 78.2% and 18.2%, while the energy and exergy efficiencies of the overall system are calculated as 84% and 33.7%, respectively. Assuming that around 16% of the oil in place in the analyzed reservoir is accessible through Huff n’ Puff, then 3,822,250kg of oil is produced while injecting 67,500kg of steam of density 0.54kg/bbl at reservoir conditions.

Separation and Recovery of Sulfur from Direct Leaching Residue from Zinc Oxygen Pressure Leaching by N-Decane

Separation and Recovery of Sulfur from Direct Leaching Residue from Zinc Oxygen Pressure Leaching by N-Decane

Regulating Sulfate-Reducing and Sulfur-Oxidizing Bacteria Via S-Doped Nife2o4 Nanosheets as Microbial Fuel Cell Anode for Simultaneous Enhancement of Sulfur and Energy Recovery

Regulating Sulfate-Reducing and Sulfur-Oxidizing Bacteria Via S-Doped Nife2o4 Nanosheets as Microbial Fuel Cell Anode for Simultaneous Enhancement of Sulfur and Energy Recovery

Effect of Cuo Addition on the Performance of V2o5-Based Oxygen Carriers for Chemical-Looping Oxidation of H2s for Efficient Sulfur Recovery from Natural Gas

Effect of Cuo Addition on the Performance of V2o5-Based Oxygen Carriers for Chemical-Looping Oxidation of H2s for Efficient Sulfur Recovery from Natural Gas

Improved Oxygen Transport Capacity and Reactivity of Catalytic Oxygen Carriers for Low Temperature Chemical-Looping Oxidation of H2s for Efficient Sulfur Recovery from Natural Gas

Improved Oxygen Transport Capacity and Reactivity of Catalytic Oxygen Carriers for Low Temperature Chemical-Looping Oxidation of H2s for Efficient Sulfur Recovery from Natural Gas

Pure hydrogen and sulfur production from H2S by an electrochemical approach using a NiCu–MoS2 catalyst

NiCu–MoS2 shows remarkable electrocatalytic activity towards H2S electrolysis and provides a promising route for easy sulfur recovery and energy saving H2 production compared to H2O electrolysis.

Desulfurization of Hydrophilic and Hydrophobic Volatile Reduced Sulfur with Elemental Sulfur Recovery in Denitrifying Bioscrubber

Desulfurization of Hydrophilic and Hydrophobic Volatile Reduced Sulfur with Elemental Sulfur Recovery in Denitrifying Bioscrubber

A Comparison between Claus and THIOPAQ Sulfur Recovery Techniques in Natural Gas Plants

A Comparison between Claus and THIOPAQ Sulfur Recovery Techniques in Natural Gas Plants