Removal Of Hydrogen Sulfide Research Articles

Combined Biological Method for Simultaneous Removal of Hydrogen Sulphide and Volatile Methylsiloxanes from Biogas

Hydrogen sulphide (H2S) and volatile methylsiloxanes (VMSs) are key pollutants from the point of view of the operators of biogas plants. H2S poses corrosive hazards, while VMSs transform into difficult-to-remove deposits, reducing the availability and yield of biogas combustion equipment. This study provides a critical overview and evaluation (so-called SWOT analysis) of implemented and promising methods to reduce the content of the above pollutants in biogas, with particular emphasis on biological techniques. The aim of the analyses was to develop an innovative concept for a hybrid biological method for the combined removal of H2S and VMSs using the same device, i.e., a two-phase biotrickling filter (BTF), in which the organic phase that intensifies the mass transfer of VMSs is in the form of a low-viscosity methyl silicone oil. The finally developed technological schematic diagram includes the basic devices and media streams. The concept is characterized by closed media circuits and comprehensively solves the problem of purifying biogas from sewage sludge. In conclusion, key issues requiring further research are identified.

Performance and Characterization of Bi-Metal Compound on Activated Carbon for Hydrogen Sulfide Removal in Biogas.

This study reports on the synthesis of bi-metal compound (BMC) adsorbents based on commercial coconut activated carbon (CAC), surface-modified with metal acetate (ZnAc2), metal oxide (ZnO), and the basic compounds potassium hydroxide (KOH) and sodium hydroxide (NaOH). The adsorbents were then characterized by scanning electron microscopy and elemental analysis, microporosity analysis through Brunauer-Emmett-Teller (BET) analysis, and thermal stability via thermogravimetric analysis. Adsorption-desorption test was conducted to determine the adsorption capacity of H2S via 1 L adsorber and 1000 ppm H2S balanced 49.95% for N2 and CO2. Characterization results revealed that the impregnated solution homogeneously covered the adsorbent surface, morphology, and properties. The adsorption test result reveals that the ZnAc2/ZnO/CAC_B had a higher H2S breakthrough adsorption capacity and performed at larger than 90% capability compared with a single modified adsorbent (ZnAc2/CAC). Therefore, the synthesized BMC adsorbents have a high H2S loading, and the abundance and low cost of CAC may lead to favorable adsorbents in H2S captured.

Removal of hydrogen sulfide from biogas by adsorption and photocatalysis: a review

Removal of hydrogen sulfide from biogas by adsorption and photocatalysis: a review

Aminated polyacrylonitrile fibers for the removal of hydrogen sulfide from natural gas at room temperature

Aminated polyacrylonitrile fibers for the removal of hydrogen sulfide from natural gas at room temperature

The influencing mechanism of O2, H2O, and CO2 on the H2S removal of food waste digestate-derived biochar with abundant minerals

Hydrogen sulfide (H2S) removal has been a significant concern in various industries. In this study, food waste digestate-derived biochar (DFW-BC), a by-product of food waste treatment with abundant minerals, was assessed for removing H2S from different simulated biogas containing oxygen (O2) and carbon dioxide (CO2) and under different moisture (H2O) contents (0% and 20%) of biochar. The influencing mechanisms of the gas conditions combined with the moisture contents were also investigated. The results showed an H2S removal of 1.75 mg g−1 for dry biochar under pure H2S, 4.29 mg g−1 for dry biochar under H2S + O2, 5.29 mg g−1 for humid biochar under H2S, and 12.50 mg g−1 for humid biochar under H2S + O2. For dry DFW-BC, the high Fe content was responsible for the O2 enhancement. In contrast, O2 + H2O activated the catalytic H2S oxidation of the less reactive minerals (mainly Ca). The inhibition of CO2 on H2S adsorption was not obvious for dry DFW-BC; the specific pore structure may have provided a buffer against the physisorption competition of CO2. However, when H2O was present on DFW-BC, the changes in critical biochar properties and sulfur speciation as opposed to that without H2O implied an evident occurrence of CO2 chemisorption. This CO2 chemisorption partially hindered O2 + H2O enhancement, decreasing the H2S removal capacity from 12.50 to 8.88 mg g−1. The negative effect was ascribed to mineral carbonation of CO2, neutralizing the alkaline surface and immobilizing metal oxides, which thus reduced the acceleration in H2S dissociation and activation in catalytic H2S oxidation by O2 + H2O.Graphical

Removal of hydrogen sulfide by layered double hydroxide loaded biochar in dynamic adsorption experiment

Biochar supported Zn-Al-Fe layered double hydroxide (LDH@BC) was synthesized by in-situ method for removal of H2S in dynamic adsorption experiment. The characterization by XRD, FT-IR, and SEM indicated that LDHs uniformly grew on the surface of BC and formed a porous structure, which facilitated the passage of gas and overcome the aggregation of LDHs. The influence factors such as ratio of BC/LDH, water vapor, initial concentration, temperature, and ratio of Al/Fe were investigated. The results showed that as LDH@BC composite possessed BC/LDH=2 and Al/Fe=1/3, the removal of H2S revealed a better efficiency under H2S concentration of 1000 mg/m3 and temperature of 180°C, and the removal efficiency was over 80% after 60 min. The presence of water vapor has less than a 10% effect on the removal of H2S. The composite after removal of H2S was investigated by XRD, FT-IR, SEM, and XPS, and mechanisms of H2S removal by LDH@BC were proposed. In regeneration experiment, the presence of water vapor reconstructed part of destroyed LDHs, which possessed high reuse efficiency and decline was less than 20%. The favorable adsorption performance provided a promising strategy for H2S removal.

Life cycle assessment of potassium lysinate for biogas upgrading

Monoethanolamine solvent (MEA) is a common solvent used in biogas upgrading plant for carbon dioxide (CO2) and hydrogen sulfide (H2S) removal. However, it has some downsides such as corrosive, high toxicity, and promotes products degradation. Alternatively, amino acid-based solvents such as potassium lysinate (LysK) have been found to have good absorption performance. It is also claimed to be more environmentally friendly as it is less toxic and has a good biodegradability. However, its actual environmental impact for the application of biogas upgrading has not been quantified in a detailed manner. Therefore, in this study, the environmental impact of LysK solvent is quantified from gate to grave in terms of Global Warming Potential (GWP), Acidification Potential (AP) and Eutrophication Potential (EP) using life cycle assessment (LCA) approach. The process was simulated using process simulator, SuperPro Designer version 10 to obtain the input-output data. LysK solvent has a low heat of absorption, which could result in lower CO2 emissions during the biogas upgrading process. However, due to its energy-intensive nature, the incineration process significantly contributed to GWP, AP, and EP. There were also emissions of NOx and SO2 from the flue gas of the incinerator. The findings of this research provide some insight on the environmental impact of utilising LysK for biogas upgrading.

Dynamics of Microbial Community and Removal of Hydrogen Sulfide (H2S) Using a Bio-Inhibitor and Its Application under the Oil Reservoir Condition

Dynamics of Microbial Community and Removal of Hydrogen Sulfide (H₂S) Using a Bio-Inhibitor and Its Application under the Oil Reservoir Condition

Multi-functional of TiO2@Ag core–shell nanostructure to prevent hydrogen sulfide formation during anaerobic digestion of sewage sludge with boosting of bio-CH4 production

Herein, we report a novel supplement called TiO2@Ag core–shell nanostructure that revealed a high removal of hydrogen sulfide gas with boosting the bio-methane production from the anaerobic digestion process of sewage sludge. TiO2@Ag core–shell nanostructure was synthesized by the deposition of Ag shell NPs on TiO2 core NPs using a reduction method. The prepared samples of the core–shell and its components were characterized using different techniques such as XRD, SEM, TEM and AFM. A concentration of TiO2@Ag core–shell NS (50 mg/L) was supplemented with anaerobic bioreactors to study their effect on the removal of hydrogen sulfide from the anaerobic digestion of sewage sludge compared to silver and titanium dioxide nanoparticles alone. The results showed a 3-fold increase in the produced bio-methane upon the use of TiO2@Ag core–shell NS with a high removal of hydrogen sulfide (91.9 %) compared to using only silver nanoparticles or titanium dioxide nanoparticles. Concisely, the prepared TiO2@Ag core–shell NS was multifunctional and more active than its components in removing hydrogen sulfide, enhancing bio-methane production, and detoxifying hazardous materials from sewage sludge.

The Comparison of Biotreatment and Chemical Treatment for Odor Control during Kitchen Waste Aerobic Composting

Odor ΨΩγemission has become mathvariant="normal" mathvariant="sans-serif-bold-italic" an important issue in kitchen waste management. Ammonia and hydrogen sulfide are the two most important odor sources as they contribute malodor and can cause health problems. As biotreatment and chemical treatment are two majorly applied technologies for odor control, in this study, they were used to remove ammonia and hydrogen sulfide and the performance of each process was compared. It was found that chemical absorption could efficiently eliminate both ammonia and hydrogenmathvariant="script" sulfide, and the removal efficiencies of ammonia and hydrogen sulfide highly depended on the pH of the adsorbent, contacting time, and gas and solution ratio (G/S). The ammonia-removal efficiency reached 100% within less than 2 s at G/S 600 and pH 0.1. The complete removal of hydrogen sulfide was achieved within 2 s at G/S 4000 and pH 13. Biotrickling filter showed better ability for hydrogen sulfide removal and the removal efficiency was 91.9%; however, the ammonia removal was only 73.5%. It suggests that chemical adsorption is more efficient compared to biotreatment for removing ammonia and hydrogen sulfide. In the combination of the two processes, biotrickling filter followed by chemical adsorption, the final concentrations of ammonia and hydrogen sulfide could meet the Level 1 standard of Emission Standards for Odor Pollution (China). The study provides a potential approach for odor control during kitchen waste aerobic composting.

A new air cleaning technology to synergistically reduce odor and bioaerosol emissions from livestock houses

Odor and bioaerosols have serious impacts on the biological safety of animal production and the ecological environment. Thus, it is particularly important to explore synergistic air cleaning technology to solve these problems. In this study, a pilot-scale air cleaning equipment were applied to an experimental manure storage house to determine the removal efficiency of gaseous pollution using four treatments groups. These treatment groups include acid scrubbing + caustic scrubbing (AC), acid scrubbing + caustic scrubbing + photocatalytic oxidation (ACP), acid scrubbing + caustic scrubbing + biological scrubbing (ACB), and acid scrubbing + caustic scrubbing + biological scrubbing + photocatalytic oxidation (ACBP). Results showed that ACP can synergistically remove odor and bioaerosol, with ammonia, odor concentrations, hydrogen sulfide, methyl mercaptan, methyl sulfide, bacterial aerosol, and fugal aerosol removal efficiencies of 89.1 %, 76.3 %, 100 %, 94.2 %, 91.2 %, 75.6 %, and 83.6 %, respectively. Furthermore, ACBP has the highest removal efficiency of 79.2 % for odor concentration, but this combination has a low inactivation efficiency (< 25 %) for bacterial aerosols. Moreover, adding biological scrubbing before photocatalytic can reduce the conversion from aromatic hydrocarbons to Oxygenated VOCs. Findings of this study provide a theoretical basis and technical support for the application of air cleaning technology in livestock houses.

Removal of hydrogen sulfide from biogas using banana peel and banana empty fruit bunch biochars as alternative adsorbents

Removal of hydrogen sulfide from biogas using banana peel and banana empty fruit bunch biochars as alternative adsorbents

Characteristics of biotrickling filter system for hydrogen sulfide removal with seasonal temperature variations: A strategy for low temperature conditions

The impact of temperature on the biological removal of hydrogen sulfide (H2S) from air is critical to its effective application in cold regions or seasons. This study investigated the effect of seasonal temperature variations (7–30 °C) on the H2S removal performance of a biotrickling filter system, with an effective H2S elimination capacity of 98.1 g/m3/h (removal efficiency = 83.1 %) achieved at temperatures of 10–12 °C. Biofilm growth was found to be accelerated by increased secretion of extracellular polymeric substances, enhanced biofilm adhesion capacity and relatively high levels of elemental sulfur accumulation, which help to retain heat within the filter bed under cold conditions. High–throughput sequencing showed that the psychrotolerant sulfur–oxidizing bacterium (SOB) Metallibacterium was gradually enriched (54.8 %) at temperatures below 15 °C. The major pathways of sulfur metabolism under low temperature conditions were determined based on the detection of enzymes related to sulfur metabolism. Finally, a strategy to enrich Metallibacterium was proposed to promote the application of biodesulfurization under low temperature conditions.

New Margin-Based Biochar for Removing Hydrogen Sulfide Generated during the Anaerobic Wastewater Treatment

The present research concerns the development of a new device and process intended for the purification and treatment of sulfurous elements, and more particularly, of hydrogen sulfide (H2S) from the biogas produced at the time of the anaerobic fermentation in the purification stations. The controlled dumps or any other unit are likely to produce biogas with concentrations of H2S harmful to the operation of the machines for the valorization of the produced biogas or deodorization. This device uses new biochar from a mixture of dehydrated digested sludge from sewage treatment plants and margins from traditional crushing units, followed by biological treatment in a liquid medium at a controlled temperature. The liquid medium is based on a margin (nutrient) with culture support (large granules of biochar) in suspension by the injection under the pressure of biogas coming from the biochar filter. Physico-chemical characterization of the biochar and a test practiced on the new device of raw biogas treatment were realized. The results showed that the newly synthesized biochar has a low specific surface and a highly undeveloped porosity. The spectrum corresponding to the images of the biochar reveals the presence of C, O, N, Al, Si, P, and Fe, as significant elements with the following respective percentages: 37.62%, 35.78%, 1.87%, 4.26%, 7.33%, 8.56%, and 4.58%. It is important to note that the C content of the biochar thus synthesized found by EDX is quite comparable to that estimated from ATG. Biogas treatment test results on the prototype object of the invention eliminated 97% of the H2S from the biogas produced.

Polyoxometalate/Ionic Liquid Desulfurization System for Hydrogen Sulfide Removal from High-Temperature Gas Stream.

The temperature of industrial gas containing harmful H2S can reach hundreds of degrees. However, few processes can be used directly for H2S removal from industrial high-temperature gas. In this work, three polyoxometalates with different central atoms ((n-Bu4N)3VMo12O40, (n-Bu4N)3PMo12O40, and (n-Bu4N)4[α-SiMo12O40]) were synthesized and dissolved in four ionic liquids (Bmim]Cl, [Bmim]HCO3, [Bmim]Mes, or [Bmim]OAc) for H2S removal from high-temperature (90–180 °C) gases. The result showed that (n-Bu4N)3VMo12O40/[Bmim]OAc exhibited the optimal desulfurization performance, maintaining more than 98.6% desulfurization efficiency within 10 h. The reacted desulfurization solution can be regenerated by blowing air. FT-IR and XPS results show that both the central atom V and the coordination atom Mo of the polyoxometalate are involved in the oxidation of H2S; after the regeneration by introducing air, V(+IV) and Mo(+IV) recovered to V(+V) and Mo(+VI), respectively. Our research shows that (n-Bu4N)3VMo12O40/[Bmim]OAc is an efficient, easy-to-regenerate, and suitable high-temperature gas desulfurization solution.

Removal of Hydrogen Sulfide and Ammonia Using a Biotrickling Filter Packed with Modified Composite Filler

The purpose of this study was to evaluate the performance of laboratory-scale biotrickling filters (BTFs) packed with composite filler and pine bark filler under different operating conditions in purifying mixed gas containing H2S and NH3. The composite filler was prepared with modified activated carbon and loaded with functional microbes, using the microbial immobilization technology combined with a nutrient sustained-release composite filler. The results showed that the composite filler could better adapt to low empty bed retention time (EBRT) and high inlet concentration than the pine bark filler. When EBRT was 40 s and the inlet load was 41 g/m3·h, the NH3 removal efficiency of the composite filler was kept above 80%, and when the inlet load was 61.5 g/m3·h, it could be stabilized at about 60%. When EBRT exceeds 34 s, the H2S removal efficiency of the two BTFs was maintained at 100%. Yet, when EBRT was 34 s, the H2S removal efficiency of the bark filler BTF dropped to &lt;80%. The microbial diversity and richness of the bark filler BTF were significantly higher than those of the composite filler BTF, which had higher community similarity under each working condition. However, the proportion of predominant bacteria in the composite filler BTF was higher than that of the bark filler BTF. As the inlet load increased, the diversity of predominant bacteria of the composite filler BTF increased, which means that the predominant bacteria were less inhibited by high-concentration odorous gases. The predominant bacteria with deodorizing function in the composite filler BTF included Pseudomonas, Comamonas, and Trichococcus, which might jointly complete nitrogen’s nitrification and denitrification processes. The proportion of these three bacteria in the composite filler BTF was higher than in the bark filler BTF.

Design and implementation of biogas as an efficient renewable energy resource for Pakistan prospects

The generation of combustible gas from anaerobic biomass captivation, is a well-known technology. Using the gas for direct combustion in household stoves is general producing power from biogas is still quite unusual in most emergent countries. The focus of this paper is to implement the importance of biogas as a substitute energy source. Bio-resources are available wide-reaching in the appearance of lasting agricultural biomass and wastes which can be deformed into biogas. Cow manure has been used for production of biogas and generation of electricity. The basic problem faced during the production of electricity is the production of biogas through anaerobic respiration which is the mixture of methane and other undesirable gases. The scrubber employed to remove the undesirable gases is very expensive and needs regular maintenance. A tap system at the top of the digester is used to remove moisture and a bucket filled with iron sponges is used to remove hydrogen sulfide. In the end, we are left with methane and some inert gases which have no adverse effect on combustion. This purified gas is used to produce electricity which is used to run the load. The benefit of this research is that this method is easily and commonly used by villagers without any hurdles.

Preparation of hydrogen sulfide adsorbent derived from spent Fenton-like reagent modified biochar and its removal characteristics for hydrogen sulfide

Hydrogen sulfide has serious harm to human health and equipment safety. Spent Fenton-like reagent poses a challenge to the environment. In this article, a cost-effective adsorbent was prepared from rice straw biochar modified with spent Fenton-like reagent, and was used to remove gaseous hydrogen sulfide. Effects of several parameters and gas components on hydrogen sulfide adsorption, and hydrogen sulfide adsorption mechanism were studied. Results show that spent Fenton-like reagent modification promotes the rise of active sites on biochar surface, but results in the decline of adsorbent specific surface area. The optimum calcination temperature of adsorbent is 300 °C, and the maximum adsorption capacity for hydrogen sulfide is up to 1000.6 mg/g at 120 °C, which is far more than similar adsorbents. Presence of gas components such as sulfur dioxide, nitric oxide or water vapor inhibits the desulfurization performance of adsorbent to varying degrees. Copper oxide is confirmed to be the key active substance for hydrogen sulfide adsorption on adsorbent, and copper sulphide, cuprous sulfide and elemental sulfur are found to be the main products of hydrogen sulfide removal on adsorbent. The study provides new ideas for utilization of spent Fenton-like reagent and development of cost-effective hydrogen sulfide adsorbent.

Adding organics to enrich mixotrophic sulfur-oxidizing bacteria under extremely acidic conditions—A novel strategy to enhance hydrogen sulfide removal

Biotreatment of high load hydrogen sulfide (H2S) can lead to rapid acidification of a bioreactor, which greatly challenges the application of bio-desulfurization technology. In this study, the bio-desulfurization performance was improved by enriching acidophilic mixotrophic sulfur-oxidizing bacteria (SOB) by adding organics under extremely acidic conditions (pH < 1.0). A biotrickling filter (BTF) for the removal of H2S was established and operated under pH < 1.0 for 420 days. In the autotrophic period, the maximum H2S elimination capacity (ECmax-H2S) was 135.8 g/m3/h with biofilm mass remaining within 11.1 g/L-BTF. The autotrophic SOB bacterium Acidithiobacillus was dominant (62.1 %). When glucose was added to the BTF system, ECmax-H2S increased by 272 % to 464.3 g/m3/h as biofilm mass increased to 22.3 g/L-BTF. The acidophilic mixotrophic SOB bacteria Mycobacterium (78.4 %) and Alicyclobacillus (20.7 %) were enriched while Acidithiobacillus was gradually eliminated (<0.1 %). Furthermore, the major sulfur metabolism pathways were identified to explore the desulfurization mechanism under extremely acidic conditions. To maintain optimal desulfurization performance and avoid biofilm overgrowth in the BTF system, biofilm mass should be maintained within 20–22 g/L-BTF. This can be achieved by adding 1.0 g/L-BTF glucose every 20 days under a load rate of H2S in 50–90 g/m3/h and a trickling liquid velocity of 1.8 m/h. Extremely acidic conditions eliminated non-aciduric microorganisms so that the addition of organics can increase the abundance of acidophilic mixotrophic SOB (>99 %), thus offering a novel strategy for enhancing H2S removal.

Estimating a target price to regenerate bio‐oils post hydrogen sulfide removal

AbstractBio‐oils such as conventional soybean, high‐oleic soybean, canola, and sunflower are valuable as bio‐solvents for removing hydrogen sulfide (H2S) from natural gas. Preceding bench‐scale studies indicate that more than 90% of H2S can be removed from a gas stream; economic analysis of such a process is necessary to determine the solvent regenerative power required and cost constraints on a to‐be‐determined solvent regeneration scheme. With the goal of processing 1000 kmol·h–1 of sour gas and removing 99.9% of H2S from gas streams with various feed concentrations, the design of an absorption unit to process natural gas using bio‐oils as the absorbing solvent was carried out through equilibrium stage analysis. A graphical method combined with the Kremser method found that a trayed tower with 14 stages, a 2 m diameter, and 8.5 m height could meet these goals successfully with a bio‐solvent flow rate of 120 kmol·h–1. Capital costs were centered on the price of an extraction column designed to meet the desired throughput. Comparison with conventional amine gas treatment was used to set a limit for the cost of treating a unit of gas, and sensitivity analysis explored the relationship between solvent recycle and cost of treating the gas. This study found that the economic viability of using bio‐oils as gas‐sweetening agents depended on developing a solvent regeneration scheme capable of recycling more than 98% of the bio‐oil bio‐solvent. The development of such a scheme is unlikely, and the overall process of using bio‐oils to sweeten sour gas is likely not economically viable. © 2022 Society of Chemical Industry and John Wiley &amp; Sons, Ltd.