Sorption Of Hydrogen Sulfide Research Articles

Thermodynamic Characteristics of the Hydrogen Sulfide Sorption Process by Ferromanganese Materials.

The work analyzes hydrogen sulfide sorption from model gas mixtures containing H2S from 1.25 × 10–3 to 1.28 × 10–4 mol/L under static conditions at temperatures 253 and 298 K on the raw manganese ore of the Ulu-Telyak deposit (Bashkortostan, Russia), manganese(IV) oxide, and manganese(IV) and iron(III) oxide mixtures. The thermodynamic models for calculating the equilibrium constants and Gibbs energy changes were analyzed. The sorption isotherms were described by the Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich models. The value of enthalpy of hydrogen sorption on the ore was −68.98 ± 3.45 kJ/mol and those on model mixtures Mn4 + Fe2O3 and MnO4 were ±12.20 kJ/mol and −103.826 ± 5.19 kJ/mol, respectively, and the entropies of the hydrogen sulfide sorption process on three manganese materials at 253 K were calculated. The limiting capacity values of manganese materials at 253 and 298 K were obtained. The morphological analysis of the ore samples, Mn4 + Fe2O3, and MnO4, before and after hydrogen sulfide sorption, was carried out at 253 K. The obtained thermodynamic parameters determine the advantage of using the raw manganese ore over pure oxides, which characterizes its effective practical application in the desulfurization process.

Iron-Containing Hypercrosslinked Composite Prepared From Polystyrene Foam Plastic in the Sorption of Toxic and Foul-Smelling Substanc

A convenient method for obtaining an iron-containing hypercrosslinked polystyrene composite based on foam plastic waste is developed. The iron-containing composite can be used for the sorption of hydrogen sulfide, toxic organic solvents, as well as foul-smelling and toxic products of degradation of natural remains—putrescine, cadaverine, indole, and skatole.

Kinetic Features of the Hydrogen Sulfide Sorption on the Ferro-Manganese Material

The kinetics of hydrogen sulfide sorption by the surface of a ferromanganese material containing in its composition a mixture of iron (II) and (III) oxides FeO × Fe2O3, takanelite (Mn, Ca) Mn4O9 × 3H2O and quartz SiO2, and which is samples of unrefined ferromanganese ore, was studied in this work. Sorption rate constant and activation energy constant values were calculated. The catalytic effect of iron (III) oxide was established, the presence of which in natural material contributes to a decrease in the H2S sorption activation energy. Based on the results of X-ray phase and chromatographic analysis methods, a chemical (redox) reaction of the conversion of hydrogen sulfide into elemental sulfur and H2O was revealed. The overall process rate is expressed in terms of the physical sorption stage and chemical transformation of the components; the influence of the rate of the third stage—reaction products desorption—on the overall rate of the process is taken into account. The limiting stage of the process is determined—a chemical reaction. The relation between the heat and the activation energy of the chemical transformation is used according to the Bronsted—Polanyi rule for catalytic processes. It was found that with an increase in the chemisorption heat, the activation energy of the chemisorption stage decreases and, as a consequence, its rate increases. The sorption process parameters were calculated—the Fe2O3 coverage degree with the initial substances and reaction products providing the maximum sorption rate, which can be a criterion for evaluating the catalytically active sites of the catalyst surface for carrying out catalytic reactions.

Metrological parameters of semiconductor sensors of hydrogen sulfide SCS-H2S with membrane coatings based on tungsten and copper oxides

The paper shows the possibility of using metal oxides W and Cu as a gas-sensitive material of a semiconductor hydrogen sulfide sensor. The results of studying the following metrological parameters of SCS-H2S are presented: calibration characteristic, selectivity, measurement range and basic error, the effect of pressure on the values of the input signal and the sensor’s resistance to concentration overloads. The principle of operation of the developed semiconductor hydrogen sulfide sensor is to change the electrical conductivity of the gas-sensitive layer as a result of sorption of hydrogen sulfide.

Crystal structure of a hydrogen sulfide sorption complex of anhydrous Mn2+-exchanged zeolite Y (FAU, Si/Al = 1.56)

Abstract The structure of a hydrogen sulfide sorption complex of anhydrous Mn2+-exchanged zeolite Y, |Mn37.5(H2S)16.5|[Si117Al75O384]-Y, has been determined at 100(1) K by single-crystal synchrotron X-ray diffraction techniques in the cubic space group Fd 3 ¯ m. The complex was prepared by treating Mn37.5-Y with H2S(g), followed by evacuation for 0.5 h. The structure was refined using all intensities to the final error index R1 = 0.062 (for Fo > 4σ(Fo)). Mn2+ ions occupy four crystallographic sites. The 16 double 6-rings per unit cell are fully occupied, about 11 with a Mn2+ ion at their centers and 5 with a Mn2+ ion on each side. The remaining Mn2+ ions are found at two single-6-ring sites, about 11.5 in supercages and 5 in sodalite cavities. H2S molecules occupy two crystallographic sites, about 11.5 in supercages and 5 in sodalite cavities. Each supercage H2S molecule coordinates to a Mn2+ ion in a single 6-ring, and each sodalite H2S molecule bridges between two double-6-ring Mn2+ ions. The Mn-S bond lengths are 2.410(20) A and 2.49(23) A, respectively.

Silicate Fiberglasses Modified with Quaternary Ammonium Base for Natural Gas Desulfurization

A new gel-like film was generated on the surface of silicate fiberglass (FG) under hydrothermal treatment with tetramethylammonium hydroxide (TMAH) water solution. By means of scanning electron microscopy (SEM)/high resolution transmission electron microscopy (HRTEM), 1H NMR magic angle spinning (MAS), and diffuse reflectance infrared fourier transform spectroscopy (DRIFTS), we revealed this film is a phase with density less than pristine FG, where TMA species, as the H2S adsorption sites, are confined. Indeed, FGs modified in this way exhibited a rather high dynamic adsorption capacity which was proportional to concentration of TMA cations bonded with very basic oxygen of Broensted acid residue. The N-modified FG sorbents showed good regenerability when in the presence of water, and the adsorbed hydrogen sulfide on the TMA+––O–Si ion pair was easily desorbed at room temperature. This gives grounds to conclude that the process of hydrogen sulfide sorption on N-modified FGs is reversible and proceeds witho...

Zn/Cu SORBENT SYNTHESIS FOR SYN-GAS PURIFICATION FROM HYDROGEN SULFIDE

The article is devoted to the synthesis of Zn/Cu sorbents and their study for the adsorption purification of synthesis gas from sulfur-containing compounds. The sorbents were synthesized using precipitation method, hydrothermal treatment, and mechanical grinding and microemulsion method. The article contains results of the physico-chemical studies of Zn/Cu sorbents with hydrogen chemisorption, nitrogen adsorption, X-ray photoelectron spectroscopy and electron microscopy. Studies showed that the most active sample, synthesized by microemulsion method, is characterized by highest surface area and highest concentration of surface active metal as compared with to other samples. The sample surface consists of 57-61 at. % Cu+2, Zn+2, Al+3 in form of oxides and 1.5-3.0 at. % Zn+2, Al+3 in form of aluminates. The sample synthesized by mechanical grinding of oxides showed the lowest activity in hydrogen sulfide sorption that explains by higher concentration of aluminates in the active face. The results of Zn/Cu sorption activity showed well correlation of hydrogen sulfide sorption capacity with sample surface area and surface concentration of active metal.Forcitation:Doluda V.Yu., Sulman M.G., Matveeva V.G., Lakina N.V., Sulman E.M. Zn/Cu sorbent synthesis for Syn-gas purification from hydrogen sulfide. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 3. P. 61-66.

Effect of Syngas Constituents on CdO- and MgO-Based Sorbents for Pre-combustion CO2 Capture

Magnesium oxide/cesium carbonate composites as well as cadmium oxide/sodium halide mixtures have been previously described as potential candidates for pre-combustion carbon dioxide capture. Here, the effects of water and hydrogen alongside CO2 were examined in simulated partial pressure swing experiments analyzed by thermogravimetric means. It was shown that the magnesium/cesium sorbents are tolerant to hydrogen at a temperature of 370 °C and that their working capacities over 25 cycles are enhanced by the addition of water to the sorption gas stream. The cadmium/sodium iodide sorbent showed a stable working capacity for 23 sorption cycles at 285 °C, but tended to lose working capacity after that point. At 305 °C, a significant loss in capacity was observed during sorption cycling. As reduction in an inert gas/hydrogen mixture was not found to commence below 400 °C, a halide promoter disintegration mechanism is assumed to be the cause of the decay. The sorption of hydrogen sulfide was also examined. Both ...

Rate phenomena in the reaction of hydrogen sulfide with a zinc oxide‐based sorbent

AbstractA zinc oxide‐based sorbent was prepared by spraying drying a slurry containing 65% zinc oxide, 18% peptized alumina, and 17% perlite. The spray dried solids were dry sieved, wet sieved, dried at 150°C for 1 h, and subsequently calcined at 635°C for 1 h to produce the sorbent. The rate of sorption of hydrogen sulfide was measured as a function of time with a Cahn VersaTherm™ thermogravimetric analyzer. Sorption rate is reported as a function of hydrogen sulfide partial pressure, temperature, and external particle size. Sorption rate can be described by a hydrogen sulfide mass‐transport model for agglomerated particles. This agglomerate kinetics model satisfactory explains rate phenomena observed in this system. © 2010 American Institute of Chemical Engineers Environ Prog, 2011

Resource recovery of cupola dust: Study on sorptive property and mechanism for hydrogen sulfide

Properties and mechanism for sorption of hydrogen sulfide (H2S) by cupola dust, which is formed by the solidification of gas exhausted from cupola furnaces, have been investigated through the characterizations, aiming at recycling as the desulfurization. From the results, the sorptive property was found to be induced by spinel-type crystals such as (MnxZn1−x)(MnyFe1−y)2O4 solid solutions in spherical matrixes comprising of amorphous SiO2 at room temperature in existence of water vapor. The further examination on the spinel-type crystals extracted by NaOH treatments revealed that H2S was dissolved in water adsorbed on the surface of the spinel-type crystals, and reacted with metal ions released from them. In addition, the H2S sorptive property was indicated to depend on amounts of Mn and Zn in the spinel-type crystals.

Kinetics of H2S Sorption on Manganese Oxide and Mn-Fe-Cu Mixed Oxide Prepared by the Complexation Technique

Hydrogen sulfide sorption activities of manganese oxide and Mn-Fe-Cu mixed oxide sorbents were examined in a fixed bed reactor. Sulfur retention capacity of Mn-O sorbent was found to be quite high at 600 °C both in the absence and presence of hydrogen gas (0.17 and 0.14 g S/g sorbent, respectively). This sorbent has a high porosity and a relatively high surface area. Best regeneration temperature of this sorbent was found as 700 °C, with a gas stream containing 6% oxygen in nitrogen. Mn-Fe-Cu mixed oxide sorbent had a lower sulfur retention capacity (0.07 g S/g sorbent). However, both of these sorbents gave quite high initial sorption rate constants, resulting very sharp breakthrough curves. Deactivation model was shown to give good agreement with the experimental H2S breakthrough curves.

Feasibility study on high-temperature sorption of hydrogen sulfide by natural soils

In this study, seven natural soils were tested for the sorption of hydrogen sulfide from coal gasification gas at high temperature. Results indicate that the LP natural soil has the best performance and the highest sulfur sorption capacity. After extracting free iron oxides, most natural soils have no sorption efficiency. The free iron oxides, therefore, proved to be the major components that react with hydrogen sulfide to form iron sulfides. The sulfur sorption capacity, either determined by EA or breakthrough time, is very close to the theoretical value based on the stoichiometric calculation with the content of free iron oxides. Moreover, the presence of CO is a positive effect while H 2 is a negative effect. This can be explained via the water-shift reaction. On the basis of the results of temperature-programmed sulfidation (TPS), the starting temperature for the sorption of hydrogen sulfide is between 623–673 K. From the analyses of temperature-programmed oxidation (TPO) and XPS, the iron polysulfides are the major products and approximately 90% regeneration efficiency can be theoretically achieved while the temperature is controlled higher than 813 K. In the regeneration tests, the results show that the LP natural soil can be regenerated and thus reused after the oxidation process. No significant degeneration occurs on the LP natural soil after five sorption/regeneration cycles. The sulfur sorption capacity of the tenth regenerated soil can be achieved at least 80% compared to the fresh one. The experimental analyzed SO 2 concentration from the regeneration process is almost identical to the theoretical calculated equilibrium concentration of the process. Maghemite is the main product after the regeneration process.

Characterization of southern Taiwan red soils as a regenerable sorbent for sorption of hydrogen sulfide from coal gas with spectroscopic techniques

The purpose of this research is to use red soils as a high-temperature regenerable sorbent for sorption of hydrogen sulfide from coal gas and collocates with a series of spectroscopic apparatuses in order to investigate the structure changes after multiple sorption/regeneration processes. Results indicate that red soils could be reused after 10 multiple sorption/regeneration cycles and maintain approximately 80% sorption efficiency. With EDS and EA analyses, residual sulfur species are detected in the 10th regenerated red soils and exist with values of 0.6 and 0.33%, respectively. Undesired sulfur species including sulfide, sulfate and elemental sulfur are further identified by XPS spectroscopy. With the best regression fitting results, sulfate species is the dominative sulfur species, which occupies approximately 71% of residual sulfur. It is believed that these residual sulfur species are the major cause to result in red soils’ deterioration after regeneration and reduce the sorption efficiency. Appreciable amounts of regeneration gases CO, CO 2 and SO 2 are detected by on-line FTIR spectroscopy. Their formation mechanisms are attributed to the different gas–solid reaction, one is the reaction of carbon and oxygen, and the other is FeS and oxygen. From the analysis of solid-state nuclear magnetic resonance spectroscopy (SSNMR), a significant change for 27Al and 29Si and it is established that a portion of aluminum is reformed into pentacoordinated structure. Formation of aluminosilicate is maybe another reason to result in deterioration as a result of the loss of surface area.

Spectroscopic study on sorption of hydrogen sulfide by means of red soil

This paper reports the results of the characterization of red soils in relation to the sorption of H 2S from coal gas at 500 °C by spectroscopic techniques in order to provide more information on red soils’ structural change both before and after reaction. In addition, by-products analysis has also been studied using Fourier transform infrared (FTIR) spectroscopy. Before and after the experiments the red soils were characterized with X-ray powder diffraction (XRPD), energy dispersion spectrum (EDS), X-ray photoelectron spectroscopy (XPS) and FTIR spectroscopy. XRPD results indicate that iron oxide species disappear from the original to reacted red soil. EDS analysis shows that a significant amount of sulfur is present in the reacted red soil, which is in agreement with the results of the elemental analysis and the calculated value based on breakthrough curve. XPS regression fitting results further indicate that sulfur retention may be associated with the iron oxides. S 2p XPS fittings point out that the major sulfur species present in the reacted red soil are composed of S −2, elemental sulfur, polysulfide, sulfite and sulfate. Additionally, the binding energy of iron shifts to a lower position for the reacted red soil, which indicates that iron oxides in the original red soil have been converted into iron sulfide. Appreciable amounts of the by-products CO 2, SO 2 and COS are detected by on-line FTIR spectroscopy during the initial and later stages of the sorption process. The formation of CO 2 is related to the water-shift reaction, and SO 2 is probably attributable to the reaction of organic matters and H 2S. The concentration of COS is quantified by GC/FPD and found it to be about 350 ppm, which is close to the equilibrium concentration of the reaction of inlet CO and H 2S at a temperature of 500 °C.

The sorption of hydrogen sulfide from hot syngas by metal oxides over supports

Six 5 wt.% metal sorbents including Mn, Fe, Cu, Co, Ce and Zn supported on γ-Al 2O 3, prepared by the incipient wetness impregnation method with calcination at 700 °C for 2 h, have been investigated for sorption of hydrogen sulfide in the temperature range of 500–700 °C. The sorption experiments were conducted in a fixed-bed reactor in terms of breakthrough curves and characterized by X-ray powder diffraction. The results reveal that the copper and manganese sorbents exhibit the best performance because they provide nearly 100% utilization, but the copper sorbent has a lower sulfur sorption capacity compared with the manganese sorbent. The zinc and cerium sorbents are not good candidates attributed to the vaporization of zinc and unexpected product for cerium. Effects of support materials on 5 wt.% manganese were also investigated by using γ-Al 2O 3, SiO 2 and TiO 2 in this study. Five weight percent Mn/γ-Al 2O 3 shows the best performance among support candidates. On the basis of XRPD and BET surface area analysis, TiO 2 appears a huge loss in BET surface area associated with a significant formation of rutile form.

Crystal structure of Mn 46Si 100Al 92O 384 · 89H 2S, a hydrogen sulfide sorption complex of fully dehydrated Mn 2+-exchanged zeolite X

The structure of Mn 46Si 100Al 92O 384 · 89H 2S ( a=24.628(7) Å), a hydrogen sulfide sorption complex of fully dehydrated, fully Mn 2+-exchanged zeolite X, has been determined by single-crystal X-ray diffraction methods in the cubic space group Fd 3 at 21(1) °C. A crystal of Mn 46-X, dehydrated at 380 °C and 2 × 10 −6 Torr for 2 days, was treated with 300 Torr of zeolitically dry H 2S(g) at ambient temperature, and its structure was determined in this atmosphere. The final error indices for the 217 reflections for which I>3 σ( I) are R 1=0.065 and R 2=0.055. In the final refinement, the 645 reflections with I>0 were used. Mn 2+ ions occupy four crystallographic sites, two more than in empty Mn 46-X. Sixteen Mn 2+ ions fill site I, at the centers of the double six-rings (Mn(octahedral)–O=2.285(9) Å). Each of 25 Mn 2+ ions at site II extends 0.49 Å into the supercage and coordinates to three six-ring oxygens and one H 2S molecule deeper in the supercage (Mn–S=2.454(8) Å). Fifty-six H 2S molecules are found at two III ′ sites where each ‘hydrogen bonds’ to two framework oxygens (S–O=3.51(4)/3.50(4) and 3.46(4)/3.52(3) Å). Altogether 81 H 2S molecules are sorbed in the eight supercages per unit cell. Of the eight sodalite cavities, 2.5 have a Mn 2+ ion at site I ′, another at site II ′, and a sulfur atom (likely HS −) bridging between them (Mn–S=2.49(2) and 2.43(3) Å, respectively, with Mn–S–Mn=94.9(9)°). The Mn 2+ ions at site I ′ are recessed deeply, 1.40 Å into their sodalite cavities from their six-rings to maximize an Mn 2+⋯Mn 2+ contact, 2.70(3) Å, through a six-ring. In contrast, the Mn 2+ ions at site II ′ are only 0.43 Å from their planes. The remaining 5.5 sodalite cavities each hold an H 2S molecule or an H 3S + ion that associates only with framework oxygen atoms by ‘hydrogen bonding’ (S–O=3.551(11) Å).

Initial Heats of H2S Adsorption on Activated Carbons: Effect of Surface Features

The sorption of hydrogen sulfide was studied on activated carbons of various origins by means of inverse gas chromatography at infinite dilution. The conditions of the experiment were dry and anaerobic. Prior to the experiments the surface of some carbon samples was oxidized using either nitric acid or ammonium persulfate. Then the structural parameters of carbons were evaluated from the sorption of nitrogen. From the IGC experiments at various temperatures, heats of adsorption were calculated. The results showed that the heat of H2S adsorption under dry anaerobic conditions does not depend on surface chemistry. The dependence of the heat of adsorption on the characteristic energy of nitrogen adsorption calculated from the Dubinin–Raduskevich equation was found. This correlation can be used to predict the heat of H2S adsorption based on the results obtained from nitrogen adsorption.

Crystal structure of a hydrogen sulfide sorption complex of fully Ca2+-exchanged zeolite X

Abstract The crystal structure of a hydrogen sulfide sorption complex of dehydrated fully Ca 2+ -exchanged zeolite X, Ca 46 Si 100 Al 92 O 384 ·ca. 149H 2 S [ a =24.864(5) A], has been determined by single-crystal X-ray diffraction methods in the cubic space group Fd 3 at 21(1)°C. A crystal of Ca 46 -X was dehydrated at 380°C and 2×10 −6 Torr for two days, followed by exposure to 200 Torr of dry hydrogen sulfide gas at 21(1)°C. The structure was determined in this atmosphere and was refined to the final error indices R 1 =0.073 and R 2 =0.067 with 407 reflections for which I >3 σ ( I ). In this structure, 16 Ca 2+ ions per unit cell fill site I at the centers of the double six-rings, and the remaining 30 are at site II in the supercages. All 46 are octahedral. Each site-II Ca 2+ ion is recessed 0.84 A into the supercage from the plane of the three oxygens to which it binds [Ca–O=2.373(9) A] and coordinates at 3.12(3) A to three H 2 S sulfur atoms in the supercage. Each of the remaining ca. 59 H 2 S `hydrogen bonds' to two 12-ring oxygens [S–O=3.27(6) A and O–S–O=95.6(13)°], (nearly) filling all 12-rings with four H 2 S molecules each. The H 2 S molecules have not dissociated upon sorption.

Crystal structure of a hydrogen sulfide sorption complex of zeolite LTA

3 ¯ m at 21(1) °C. The structure was refined to the final error indices R = 0.047 and R w = 0.033 with 153 reflections for which I > 3σ(I). Twelve H 2 S molecules are sorbed per unit cell. Eight Na + ions are found at two different 6-oxygen-ring sites, where each coordinates to three framework oxygens at ca. 2.32(2) Å. Six of the eight Na + ions extend 0.47(1) Å into the large cavity from the (111) planes of the 6 rings, where each coordinates at 2.98(2) Å to one H 2 S sulfur in the large cavity. The remaining two 6 ring Na + ions do not associate with H 2 S and are located near the centers of their 6 rings. Three Na + ions are found in 8-oxygen-ring planes, where each coordinates to one framework oxygen at 2.39(2) Å and to two H 2 S sulfurs in the large cavities at 2.74(3) Å. The twelfth Na + ion coordinates to the four framework oxygens of a 4-ring at 2.71 (3) Å, and to one or two of the above H 2 S molecules at 2.78(6) Å. The sodalite cavities are empty.

Crystal Structure of a Hydrogen Sulfide Sorption Complex of Dehydrated Partially Cobalt(II)-Exchanged Zeolite A

The crystal structure of a hydrogen sulfide sorption complex of partially Co(II)-exchanged zeolite A, Co4Na4-A·11H2S (a = 12.149(2) Å) has been determined by single-crystal X-ray diffraction techniques in the cubic space group Pm3̄m at 21(1) °C. The crystal of Co4Na4-A (initially light pink) was dehydrated at 380 °C and 2 × 10-6 Torr for 2 days (deep blue), followed by exposure to ca. 700 Torr of hydrogen sulfide gas at room temperature (black). The structure was refined to the final error indices R1 = 0.055 and Rw = 0.051 with 171 reflections for which I > 3σ(I). Four Co(II) ions are found at 6-oxygen ring sites where each coordinates to three framework oxygens at 2.24(1) Å. Each Co(II) ion is recessed 0.65 Å into the large cavity from the (111) plane of the nearest framework oxygens and coordinates at 2.60(2) Å to one H2S sulfur in the large cavity. Each of four Na+ ions lies between a 4-ring and an 8-ring in the large cavity, where it coordinates to a framework oxygen at 2.75 Å and to an H2S sulfur in the large cavity at 2.87 Å. Each of three additional H2S molecules is near the center of an 8-oxygen ring, where it coordinates to one or two Na+ ions and “hydrogen bonds” with 8-ring oxygens.