Removal Of Hydrogen Sulfide Research Articles

Iron-organic frameworks-derived iron oxide adsorbents for hydrogen sulfide removal at room temperature

We have reported iron-based MOFs by sonication of organic linkers with a freshly prepared iron hydroxide, which served as templates to yield iron oxide adsorbents after calcination. The PXRD analysis confirmed the presence of α-Fe2O3 and Na2SO4 in MOF-derived adsorbents. The XPS analysis confirmed the presence of both Fe2+ and Fe3+ species in all MOFs and derived iron oxide adsorbents. These adsorbents were studied for H2S removal in both dry and moist conditions at room temperature. The iron terephthalate MOF-derived iron oxide adsorbent showed the maximum adsorption capacity of 36.2 mg g−1 at moist conditions. The H2S removal process over iron oxide adsorbents was governed by the oxidation of H2S into sulfur and sulfates by Fe3+ and adsorbed oxygen. The spent adsorbent was regenerated by NH4OH to produce ammonium sulfate (liquid fertilizer), which is a novel approach to convert waste into value-added products.

Treatment of mixed waste-gas containing H2S, dichloromethane and tetrahydrofuran by a multi-layer biotrickling filter

Biotrickling filter could be used for the abatement of volatile inorganic compounds (VICs) and volatile organic compounds (VOCs) simultaneously, a multi-layer biotrickling filter (MLBTF) system was constructed to lift the contradiction of pH between VICs degrader and VOCs degrader. The pH levels of the bottom, middle, and top layers of the MLBTF were controlled at 4.5, 6.0, and 7.5, respectively. Biological removal of ternary mixed hydrogen sulfide (H2S), tetrahydrofuran (THF), and dichloromethane (DCM) was conducted for 120 days. The result indicated that H2S was mainly removed in the bottom layer, the THF and DCM were mainly removed in the middle layer. The removal efficiency of 200 mg/L H2S, 100 mg/L THF, and 100 mg/L DCM were all exceeded 95% with an empty bed residence time of 35 s. The maximum elimination capabilities of H2S, THF, and DCM were 52.5, 26.7, and 17.2 g/(m3·h) respectively. Results from polymerase chain reaction denaturing gradient gel electrophoresis revealed that the dominant microorganisms in the bottom layer of MLBTF were Methylosinus sp. and Acidithiobacillus sp. The Pseudomonas sp., Achromobacter sp., and Methylobacterium sp. remained dominant throughout the operation in the middle and top layers. These findings demonstrated that the proposed method can effectively enhance the performance of VICs and VOCs removal by controlling pH and microbial community in each layer of the MLBTF. It is believed that this work provides a new insight into the biological removal of VOCs by the MLBTF.

Removal of hydrogen sulfide from a binary mixture with methane gas, using IRMOF-1: a theoretical investigation.

The natural gas is mainly composed by methane, ethane, propane, and contaminants. Among these contaminants, the H2S gas has some specific characteristics such as its toxicity and corrosion, besides reducing the combustion power efficiency of natural gas. In this context, metal-organic frameworks appear as promising materials for purification of natural gas by adsorption, due to their large surface area and pore volume. In this work, Grand Canonical Monte Carlo method was used to study the adsorption and separation of CH4:H2S mixture by IRMOF-1. The adsorption isotherms were computed for the pure components, and at different compositions of binary mixture (90:10, 75:25, 50:50, 25:75, and 10:90). Interaction energy obtained with the semiempirical method confirmed that the inorganic unit is the preferred site for CH4 and H2S adsorption. Moreover, in a gas mixture with 50:50 proportion of CH4:H2S mixture, methane adsorbs preferentially in the inorganic unit only at pressures close to 20bar. Non-covalent interaction (NCI) analyses indicated that the interactions involving H2S are more effective than that for CH4, due to an electrostatic character in the H2S interaction. The simulations also showed that the separation of gases occurs in all compositions and pressures studied, suggesting that IRMOF-1 has a promising potential for this application.

Microwave-assisted synthesis of Zn-Fe adsorbent supported on alumina: Effect of Zn to Fe ratio on syngas desulfurization performance

Before syngas from gasification of biomass could be used as synthesis fuel or chemical feedstock, it requires the removal of hydrogen sulfide (H2S) to meet the purity standard level of those applications. In this study, Zn-Fe/Al2O3 were successfully synthesized by a microwave-assisted wet incipient impregnation technique for use as adsorbent for H2S removal. The characterization of synthesized adsorbents showed that the oxide form of Zn and Fe present on the surface of adsorbents were zinc oxide (ZnO), magnetite (Fe3O4), and zinc ferrite (ZnFe2O4). While the reduction of adsorbent was mostly due to that of iron oxide. The reduced adsorbents might consist of ZnO/Fe3O4/FeO/Fe on alumina as support. At relatively high space velocity (26,000 h−1) the adsorbents were able to reduce the H2S concentration from 250 ppm at the inlet to around 45 ppm, 35 ppm, and 25 ppm at the outlet by adsorbent 1ZnFe, 2ZnFe, and 3ZnFe; respectively. The removal efficiency for adsorbent 1ZnFe, 2ZnFe, and 3ZnFe were 82%, 86%, and 90%; respectively. Results also shown an increase in adsorbent lifetime with the increase of the Zn to Fe ratio.

Metal organic framework derived NaCoxOy for room temperature hydrogen sulfide removal

Novel NaCoxOy adsorbents were fabricated by air calcination of (Na,Co)-organic frameworks at 700 °C. The NaCoxOy crystallized as hexagonal microsheets of 100–200 nm thickness with the presence of some polyhedral nanocrystals. The surface area was in the range of 1.15–1.90 m2 g−1. X-ray photoelectron spectroscopy (XPS) analysis confirmed Co2+ and Co3+ sites in MOFs, which were preserved in NaCoxOy. The synthesized adsorbents were studied for room-temperature H2S removal in both dry and moist conditions. NaCoxOy adsorbents were found ~ 80 times better than the MOF precursors. The maximum adsorption capacity of 168.2 mg g−1 was recorded for a 500 ppm H2S concentration flowing at a rate of 0.1 L min−1. The adsorption capacity decreased in the moist condition due to the competitive nature of water molecules for the H2S-binding sites. The PXRD analysis predicted Co3S4, CoSO4, Co3O4, and Co(OH)2 in the H2S-exposed sample. The XPS analysis confirmed the formation of sulfide, sulfur, and sulfate as the products of H2S oxidation at room temperature. The work reported here is the first study on the use of NaCoxOy type materials for H2S remediation.

Ferric Oxide-Containing Waterworks Sludge Reduces Emissions of Hydrogen Sulfide in Biogas Plants and the Needs for Virgin Chemicals

Ferric oxide-containing waterworks sludge can be used to reduce the formation of hydrogen sulfide during anaerobic digestion. The ferric compound is reduced biochemically in the digester and forms insoluble pyrite in digester sludge. Virgin ferric chloride is often used to solve the hydrogen sulfide problem. Since 2013, Sydvatten AB has supplied a growing number of digestion plants in Sweden with ferric-containing dewatered waterworks sludge derived from the drinking water treatment plant Ringsjöverket to limit the formation of hydrogen sulfide. At the waterworks, ferric chloride is added to enhance the coagulation of organic matter from the source water. The sludge formed in this process is dewatered and landfilled, but also recycled in biogas production in order to decrease the hydrogen sulfide concentration. In this study, the use of sludge for hydrogen sulfide removal in digesters was technically and economically evaluated via case studies from 13 full-scale digesters in Sweden. Compared with the use of fresh ferric chloride, the operational costs are reduced by up to 50% by using sludge. The quality of the sludge is high and its content in metals is low or very low, especially when compared with the requirements of different certification standards for biosolid reuse applied in Sweden. The addition of waterworks sludge containing iron to a digester for the removal of dissolved hydrogen sulfide is a technically and economically good alternative when producing biogas. It is also one step closer to a circular economy, as replacing the use of virgin chemicals with the by-product waterworks sludge saves energy and materials and reduces the carbon footprint of the waterworks.

Pollutant-Removing Biofilter Strains Associated with High Ammonia and Hydrogen Sulfide Removal Rate in a Livestock Wastewater Treatment Facility

This study analyzed the microbial community metagenomically to determine the cause of the functionality of a livestock wastewater treatment facility that can effectively remove pollutants, such as ammonia and hydrogen sulfide. Illumina MiSeq sequencing was used in analyzing the composition and structure of the microbial community, and the 16S rRNA gene was used. Through Illumina MiSeq sequencing, information such as diversity indicators as well as the composition and structure of microbial communities present in the livestock wastewater treatment facility were obtained, and differences between microbial communities present in the investigated samples were compared. The number of reads, operational taxonomic units, and species richness were lower in influent sample (NLF), where the wastewater enters, than in effluent sample (NL), in which treated wastewater is found. This difference was greater in June 2019 than in January 2020, and the removal rates of ammonia (86.93%) and hydrogen sulfide (99.72%) were also higher in June 2019. In both areas, the community composition was similar in January 2020, whereas the influent sample (NLF) and effluent sample (NL) areas in June 2019 were dominated by Proteobacteria (76.23%) and Firmicutes (67.13%), respectively. Oleiphilaceae (40.89%) and Thioalkalibacteraceae (12.91%), which are related to ammonia and hydrogen sulfide removal, respectively, were identified in influent sample (NLF) in June 2019. They were more abundant in June 2019 than in January 2020. Therefore, the functionality of the livestock wastewater treatment facility was affected by characteristics, including the composition of the microbial community. Compared to Illumina MiSeq sequencing, fewer species were isolated and identified in both areas using culture-based methods, suggesting Illumina MiSeq sequencing as a powerful tool to determine the relevance of microbial communities for pollutant removal.

Performance of V<sub>2</sub>O<sub>5</sub>-TiO<sub>2</sub> Catalyst Prepared by Various Methods for Removal of Hydrogen Sulfide Emitted from Steel Smelting Process

Performance of V<sub>2</sub>O<sub>5</sub>-TiO<sub>2</sub> Catalyst Prepared by Various Methods for Removal of Hydrogen Sulfide Emitted from Steel Smelting Process

Performance of a fungal-biofilter for simultaneous removal of hydrogen sulfide and butyl acetate

Performance of a fungal-biofilter for simultaneous removal of hydrogen sulfide and butyl acetate

H2S Removal from Groundwater by Chemical Free Advanced Oxidation Process Using UV-C/VUV Radiation.

Sulfide species may be present in groundwater due to natural processes or due to anthropogenic activity. H2S contamination poses odor nuisance and may also lead to adverse health effects. Advanced oxidation processes (AOPs) are considered promising treatments for hydrogen-sulfide removal from water, but conventional AOPs usually require continuous chemical dosing, as well as post-treatment, when solid catalysts are applied. Vacuum-UV (VUV) radiation can generate ·OH in situ via water photolysis, initiating chemical-free AOP. The present study investigated the applicability of VUV-based AOP for removal of H2S both in synthetic solutions and in real groundwater, comparing combined UV-C/VUV and UV-C only radiation in a continuous-flow reactor. In deionized water, H2S degradation was much faster under the combined radiation, dominated by indirect photolysis, and indicated the formation of sulfite intermediates that convert to sulfate at high radiation doses. Sulfide was efficiently removed from natural groundwater by the two examined lamps, with no clear preference between them. However, in anoxic conditions, common in sulfide-containing groundwater, a small advantage for the combined lamp was observed. These results demonstrate the potential of utilizing VUV-based AOP for treating H2S contamination in groundwater as a chemical-free treatment, which can be especially attractive to remote small treatment facilities.

Использование электролизных процессов в безреагентной водоочистке: удаление сероводорода, органического железа, синтетических поверхностно-активных веществ

The use of electrotechnical equipment refers to reagent-free methods and makes it possible to simplify the automation schemes for facilities for removing pollutants from aqueous solutions. The article substantiates the approaches and structural diagrams of a reagent-free water purification unit based on the use of electrolysis processes. During the research, the processes of oxidation of pollutants were analyzed when a block of electrochemical action on aqueous solutions was used during processing. A diaphragm cell with an inactive membrane volume of 3.5 liters was used to implement the appropriate reagent-free method for removing pollutants from aqueous solutions. The solution of scientific and practical problems is shown: removal of hydrogen sulfide from water from a well before feeding it to the technological lines of a dairy plant; purification of waste water from an enterprise for the production of gelatinous products from organic iron and related pollutants; reduction of waste water pollutants of a cosmetology enterprise, with a focus on destructive effects on synthetic surfactants. Based on the analysis of the results and treatment modes of three aqueous solutions, the structure of the block of reagent-free electrolysis treatment of aqueous solutions is substantiated. As a result of experimental studies, the prospects of electrical equipment have been confirmed. The reagent-free method will simplify the automation schemes for facilities for removing pollutants from aqueous solutions - accordingly, increase the reliability of such computer-integrated solutions. Further research should be directed to the substantiation, creation and parameterization of mathematical models of combined electrotechnological water treatment complexes. Key words: environmental safety, electrotechnological complex, waste water, reagent-free method, electrolysis processes

Perspectives on reactive separation and removal of hydrogen sulfide

The growing demand for energy and stringent pollutant emission control in sour fuels makes it essential to develop more efficient approaches in H2S gas removal and subsequent treatment to recover sulfur. Several methods using oxidative or non-oxidative decomposition of H2S to remove or inhibit H2S from gas stream have been extensively explored over the past few decades, including catalytic process, reactive absorption, photocatalysis, electrocatalysis, thermal catalysis, membrane-assisted catalysis, and multistep thermochemical decomposition. This article reviews the recent advances in reactive H2S separation combining computational simulation with experimental development. In particular, material and catalyst design, mechanistic insights of the reactions, and applicable reaction processes are discussed. These pioneering works suggest that understanding H2S decomposition reaction mechanism at molecular level is important in the optimization of material and process design. The perspectives are also given on the viability of oxidative or non-oxidative decomposition of H2S.

Metal-organic framework-derived NaMnxOy hexagonal microsheets for superior adsorptive-oxidative removal of hydrogen sulfide in ambient conditions

We have reported the fabrication of NaMnxOy from air calcination of (Na,Mn)-organic frameworks. The hexagonal microsheets of NaMnxOy formed irrespective of the type of organic linker or MOF morphology. The adsorption capacity of NaMnxOy was found 40–70 times higher than the precursor MOF. The best adsorbent showed the maximum adsorption capacity of 818.7 and 116.3 mg g−1 in wet and dry condition, respectively. The experimental parameters like mass of adsorbent and flow rate played a decisive role in the adsorption capacity. X-ray diffraction and photoelectron spectroscopy analyses predicted NaMnxSy, S, and MnSO4 as the reaction products. The spent adsorbent was stripped with an ammonia solution to yield ammonium sulfate (liquid fertilizer) and regenerated adsorbent. The regenerated adsorbent retained an adsorption capacity of more than 110 mg g−1 in the fourth cycle. It is the first report of NaMnxOy formation from the MOF precursor.

Activated Bio-Carbons Prepared from the Residue of Supercritical Extraction of Raw Plants and Their Application for Removal of Nitrogen Dioxide and Hydrogen Sulfide from the Gas Phase.

The waste materials left after supercritical extraction of hop cones and marigold flowers were tested as precursors of activated bio-carbons. Adsorbents were produced by means of the physical (also called thermal) activation method using CO2 as the gasifying agent. All the activated bio-carbons were tested for the removal of NO2 and H2S from the gas phase under dry and wet conditions. The effects of the type of precursor and the activation procedure on the porous structure development, the acid-base properties of the surface, as well as the sorption capacities of the materials produced were also checked. The final products were bio-carbons of medium developed surface area with a basic surface nature, characterized by their high effectiveness in removal of gas pollutants of acidic character, especially nitrogen dioxide (sorption capacities in the range from 12.5 to 102.6 mg/g). It was proved that the toxic gas removal efficiency depends considerably on the sorption conditions and the activation procedure. All materials showed greater effectiveness in gas removal when the process of adsorption was carried out in the presence of steam.

Recent advances in microbial capture of hydrogen sulfide from sour gas via sulfur-oxidizing bacteria.

Biological desulfurization offers several remarkably environmental advantages of operation at ambient temperature and atmospheric pressure, no demand of toxic chemicals as well as the formation of biologically re‐usable sulfur (S0), which has attracted increasing attention compared to conventionally physicochemical approaches in removing hydrogen sulfide from sour gas. However, the low biomass of SOB, the acidification of process solution, the recovery of SOB, and the selectivity of bio‐S0 limit its industrial application. Therefore, more efforts should be made in the improvement of the BDS process for its industrial application via different research perspectives. This review summarized the recent research advances in the microbial capture of hydrogen sulfide from sour gas based on strain modification, absorption enhancement, and bioreactor modification. Several efficient solutions to limitations for the BDS process were proposed, which paved the way for the future development of BDS industrialization.

Fuzzy optimization design of multicomponent refinery hydrogen network

Hydrogen and light hydrocarbon components are essential resources of the refinery. The optimization of the refinery hydrogen system and recovery of the light hydrocarbon components contained in the gas streams are key strategies to reduce the operating costs for sustainable development. Many research efforts have been focused on the optimization of single impurity hydrogen network, and the flowrates of the hydrogen sources and sinks are assumed to be constant. However, their flowrates vary along with the quality of crude oil and refinery processing plans. A general superstructure of multicomponent refinery hydrogen network is proposed, which considers four components, namely H 2 , H 2 S, CH 4 and C 2 + , as well as the flowrate variations of hydrogen source and hydrogen sink. The mathematical model based on the superstructure is developed with objective functions, including the minimization of total annualized cost and the maximization of overall satisfaction of the hydrogen network. Moreover, the model considers the removal of hydrogen sulfide and the recovery of light hydrocarbon components ( i . e ., C 2 + ) in the optimization. To verify the applicability of the proposed mathematical model, a simplified industrial case study with four scenarios is solved. The optimization results show that the economic benefit can be maximized by considering both the direct reuse of gas streams from high-pressure separator (HP gas stream) and from low-pressure separator (LP gas stream) and the recovery of the light hydrocarbon streams. The fuzzy optimization method can be used to guide the optimal design of the refinery hydrogen system with multi-period variable flowrates.

ПЕРСПЕКТИВА ИСПОЛЬЗОВАНИЯ МЕТИЛДИЭТАНОЛАМИНА НА БЛОКЕ ОЧИСТКИ ТЕХНОЛОГИЧЕСКИХ ГАЗОВЫХ ПОТОКОВ УСТАНОВКИ ГИДРООЧИСТКИ ДИЗЕЛЬНОГО ТОПЛИВА АО «АНХК» ДЛЯ УДАЛЕНИЯ СЕРОВОДОРОДА

It was considered the possibility of using methyldiethanolamine solution instead of
 monoethanolamine solution for hydrogen sulfide removal from process gases in diesel fuel 
 hydrocleaning unit JSC «ANHK». It is demonstrated some advantages and disadvantages 
 methyldiethanolamine-based circulating absorbent in comparison of monoethanolamine-based absor bent.

Surrogate-assisted optimization of refinery hydrogen networks with hydrogen sulfide removal

Hydrogen management is very important for the production of clean fuels such as low-sulfur gasoline and diesel. As a key contaminant in the hydrogen network, hydrogen sulfide not only deactivates catalysts but also corrodes equipments. Hence, it is necessary to integrate hydrogen sulfide removal process model into the optimization of hydrogen allocation network. However, a desulfurization process model with simplifications and assumptions may yield suboptimal results and a model based on rigorous process mechanism may require high computational cost. To solve this problem, this paper proposes a novel approach for simultaneous optimization of refinery hydrogen allocation network and hydrogen sulfide removal processes. The optimization is realized in two steps. First, surrogate models are developed as approximations to the rigorous process and thermodynamic model for the desulfurization processes. Second, the surrogate model is embedded into the mathematical programming model for hydrogen network optimization. The effectiveness of the proposed approach is illustrated by its application to a case study taken from a real refinery. Result comparison between the proposed method and a literature model based on simplified desulfurization models is carried out, proving that, with the proposed method, more practical optimization result can be obtained with much less computational effort.

Physicochemical Characteristics of Activated Carbon Impregnated with Different Type of Metal Oxide Nanoparticles towards Hydrogen Sulfide Removal

It is highly anticipated to understand the influence of physicochemical characteristics of different types metal oxide nanoparticles impregnated onto palm shell activated carbon (PSAC) adsorbent towards hydrogen sulfide (H 2S) removal. Alkaline precipitation method was used to synthesis metal oxide nanoparticles (CeO 2, NiO, CuO, and Fe 2O 3). The synthesised metal oxide nanoparticles were then impregnated in the pre-oxidized PSAC adsorbents (Ce/PSAC, Ni/PSAC, Cu/PSAC and Fe/PSAC). The prepared adsorbent was then analysed via Scanning Electron Microscope – Energy Dispersive X-ray (SEM-EDX), Thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR) and H 2S adsorption analysis. Based on H 2S adsorption study, different types of metal oxide nanoparticles impregnated on PSAC adsorbent showed different trend of breakthrough time and adsorption capacity. PSAC adsorbent that was modified with metals oxide nanoparticles shows efficient result compared to raw PSAC adsorbent. Among metal oxide nanoparticles, Cu/PSAC adsorbent gives the higher adsorption capacity (86.60 mg H 2S/g Cu/PSAC) and breakthrough time (80 minutes) compared to the rest of adsorbents.

Preparation of Potassium Permanganate Confined in Porous Carbon Synthesized from Palm Kernel Shell and its Application for Hydrogen Sulfide Removal

The goal of this study is to investigate the efficacy of potassium permanganate (KMnO4) confined in porous carbon for hydrogen sulfide removal. As porous support, carbon was prepared by carbonization process of abundantly biomass source of palm kernel shell (named KATKS). The surface of porous carbon was first modified using hydrogen peroxide oxidation. The confinement process was carried out by an impregnation process. The KMnO4 contents in porous carbon were varied i.e. 5%, 10%, and 20% w/w (KMnO4-%/KATKS-Ox). Materials were characterized by N2-sorption analysis and SEM-EDX. The results showed that KATKS possesses a high specific surface area of ca. 700 m2/g. Due to the impregnation of KMnO4, the specific surface area of KMnO4-%/KATKS-Ox decreased to ca. 450 m2/g. SEM-EDX revealed a successful confinement process in which elements of K, Mn, and O were displayed and dispersed on the carbon surface. In the hydrogen sulfide (H2S) oxidation testing, KMnO4-20%/KATKS-Ox showed the highest performance of H2S removal compared to other materials due to the high amount of KMnO4. KMnO4-20%/KATKS-Ox could reduce until 98.7% of H2S. This is remarkably higher than only using bulk KMnO4 (without confinement) which showed activity of ca. 70% reduction.