Sulfur-containing Gases Research Articles

Технологии подавления серосодержащих газов при ведении горных работ

Технологии подавления серосодержащих газов при ведении горных работ

Transformations of pyrite in different associations during pyrolysis of coal

The samples of pure pyrite, the mixtures of FeS2 or FeS loaded on a low-ash coal char, and an acid-washed coal with high content of pyrite were used to investigate the transformations of pyrite with different physical associations during pyrolysis. The presence of low-ash coal char, although affected the evolution of sulfur-containing gases in vapor phase, had little influence on thermal decomposition of pyrite at 450–650°C. Pyrite conversion above 920°C, especially transformation of the formed FeS into elemental iron, was facilitated primarily by the char matrix entity. During pyrolysis of coal, isolated agglomerates of single pyrite crystals were transformed into individual aggregates in the gaps of coke grains, while most of pyrite embedded in the coal particles or located at the edge of coal particles decomposed to the Fe–S phases which remain inside or closely in contact with the carbon matrix. Meanwhile low-sulfur Fe–S phases in the pyrolysis products of coal were mainly represented as FeSy (0<y<1).

Release of organic sulfur as sulfur-containing gases during low temperature pyrolysis of sewage sludge

This study reports the release of five sulfur-containing odorants (H2S, SO2, COS, CS2 and CH3SH) during the pyrolysis of sewage sludge. Pyrolysis experiments using both raw sewage sludge and seven sludge samples loaded with various organic sulfur compounds were performed to determine the effects of the type of organic sulfur on the release of sulfur-containing gases. It was observed that the formation of H2S, the predominant odorant, significantly increases at temperatures above 150°C. Aliphatic and aromatic sulfur compounds were found to be the two main organic sulfur sources for the release of sulfur-containing gases. The release of sulfur-containing gases from aliphatic sulfur greatly increases at 250°C, whereas significant sulfur-containing gases are released from aromatic sulfur at relatively high temperatures of 350–450°C. It was also observed that the presence of sulphonic acid and thiophene in sludge does not significantly affect the release of sulfur-containing gases.

Equilibrium Analysis on Sulfur Material in Oxyfuel Combustion

To study migration and transformation of sulfur species in oxyfuel combustion, the study attempts to analyze distribution of sulfur compounds with thermodynamic equilibrium. Results show that sulfur-containing gases predominantly are SO2 and SO3, the maximum thermodynamic equilibrium concentration of those in oxyfuel combustion respectively increase by 3.4 and 4.5 times compared with the conventional combustion. Furthermore, SO2 gas formation rate decreases while SO3 increases under oxyfuel combustion. Sulfur-containing gases are generally more sensitive to temperature and excess air coefficient. The amount of sulfur compounds significantly increases in oxyfuel combustion.

In situ speciation of sulfur vapors by X-ray absorption near edge structure spectroscopy

Despite the tremendous importance for geologic systems, there is limited knowledge of sulfur-containing gas-phase geochemical reactions that take place at elevated temperatures, including up to 1000K. This deficit is at least partly caused by a lack of suitable experimental techniques to monitor and quantify potential reactions. We developed a new furnace design that can heat solid samples to specific temperatures while in situ X-ray absorption spectra of the gas-phase species are collected at the sulfur K-edge at about 2400eV for X-ray absorption near edge structure (XANES) spectroscopy. Our experimental design improves previous furnace systems developed to generate sulfur vapors for spectrometry measurements and earlier sulfur XANES spectroscopic analyses of sulfur-containing gases and vapors. The new design minimizes contamination by air, water vapor, and stainless steel. Our results demonstrate that vapors emitted from elemental sulfur heated to different temperatures are similar to previous findings, but we can now resolve long-held interpretative discrepancies for sulfur vapor speciation, some of which resulted from the misidentification of vapors due to reactions between the sulfur vapors and furnace materials. We also used the new design to quantify the sulfur vapor species produced from elemental sulfur reacted with water over a range of temperatures. At low temperatures, like 363K (~90°C), the gas consisted of different sulfur species, whereas at temperatures greater than 550K (~280°C), the gas present in the furnace was only SO2. These quantitative findings show promise that future reaction kinetics can be done by using our experimental spectrometry system.

Quantification of individual polysulfides in lab-scale and full-scale desulfurisation bioreactors

Environmental context Emission into the atmosphere of gaseous streams containing sulfur compounds, such as H2S and SOx, will lead to the unwanted formation of acid rain. In order to prevent this, biological processes can be employed to treat sulfur-containing gas streams. In this study, we describe a way to investigate the speciation of polysulfide anions in biodesulfurisation systems, which might enable further understanding and development of these processes. Abstract Environmental pollution caused by the combustion of fuel sources containing inorganic and organic sulfur compounds such as hydrogen sulfide (H2S) and thiols, is a global issue as it leads to SO2 emissions. To remove H2S from gas streams such as liquefied petroleum gas (LPG), biological processes can be applied. In these processes, polysulfide anions (Sx2–) play a significant role as they enhance the dissolution of H2S and act as intermediates in the biological oxidation of hydrogen sulfide ions to elemental sulfur. Despite their important role, the distribution of the various polysulfide species in full-scale biodesulfurisation systems has not yet been reported. With conventionally applied spectrophotometric analysis it is only possible to determine the total concentration of Sx2–. Moreover, this method is very sensitive to matrix effects. In this paper, we apply a method that relies on the derivatisation of Sx2– to dimethyl polysulfanes. Owing to the instability of higher dimethyl polysulfanes (Me2S4 to Me2S8), standards are not commercially available and had to be prepared by us. We present a simplified quantification method for higher dimethyl polysulfanes by calculating high performance liquid chromatogaphy (HPLC) UV response factors based on the addition of internal standards. The method was subsequently used to assess the distribution of polysulfide anions in both a laboratory-scale and a full-scale biodesulfurisation unit. We found that the average chain length of polysulfides strongly depends on the process conditions and a maximum of 5.33 sulfur atoms per polysulfide molecule was measured. Results of this study are required by mechanistic and kinetic models that attempt to describe product selectivity of sulfide oxidising bioreactors.

The fate of sulfur during rapid pyrolysis of scrap tires

The fate of sulfur during rapid pyrolysis of scrap tires at temperatures from 673 to 1073K was investigated. Sulfur was predominant in the forms of thiophenic and inorganic sulfides in raw scrap tires. In the pyrolysis process, sulfur in organic forms was unstable and decomposed, leading to the sulfur release into tar and gases. At 673 and 773K, a considerable amount of sulfur was distributed in tar. Temperature increasing from 773 to 973K promoted tar decomposition and facilitated sulfur release into gases. At 1073K, the interactions between volatiles and char stimulated the formation of high-molecular-weight sulfur-containing compounds. After pyrolysis, almost half of the total content of sulfur in raw scrap tires still remained in the char and was mostly in the form of sulfides. Moreover, at temperatures higher than 873K, part of sulfur in the char was immobilized in the sulfates. In the pyrolysis gases, H2S was the main sulfur-containing gas. Increasing temperature stimulated the decomposition of organic polymers in scrap tires and more H2S was formed. Besides H2S, other sulfur-containing gases such as CH3SH, COS and SO2 were produced during the rapid pyrolysis of scrap tires.

활성탄소섬유를 이용한 유황계 혼합악취 제거

활성탄소섬유를 이용한 유황계 혼합악취 제거

Separation of hydrocarbon and sulfur-containing gases on a new poly-(1-trimethylsilyl-1-propyne)/poly-(1-phenyl-1-propyne) mixed stationary phase in the presence of water

The separation of hydrocarbons (methane, ethane, propane, n-butane, ethylene, and propylene) and sulfur-containing gases (hydrogen disulfide, sulfur dioxide, carbonyl sulfide) on a new mixed stationary phase poly-(1-trimethylsilyl-1-propyne)/poly-(1-phenyl-1-propyne) in the presence of water has been studied by gas chromatography. It has been demonstrated that the new mixed stationary phase outperforms the known polymeric adsorbents and stationary phases by resolution, asymmetry factor, and column efficiency.

Characterization and physiochemical studies of crosslinked thiolated polyvinyl alcohol hydrogels

Modification and crosslinking of polyvinyl alcohol (PVA) by thiolation using thioglycolic acid (TGlA) and various crosslinkers were carried out. The crosslinked thiolated PVA (TPVA) hydrogels were characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and Fourier transform infra red spectroscopy coupled with thermal analysis (TG-FTIR) techniques. The crosslinking of the resultant material was carried out using three crosslinker sodium trimetaphosphate (STMP), glyoxal and boric acid. The influence of esterification and crosslinking on the physical and chemical properties of the material was studied. XRD showed that after crosslinking the crystallinity of TPVA hydrogels decreased. These results were further substantiated by DSC observations. The thermal stability of the TPVA hydrogels is enhanced. A significant variation in the initial decomposition temperature was observed with respect to different STMP crosslinked samples having varying TGlA concentration and different crosslinkers. The coupled TG-FTIR studies of crosslinked samples at different temperatures show that the evolution of sulfur-containing gases (carbon disulfide and carbon monosulfide) is being prominent for this material.

Chromatographic and adsorption properties of poly(1-trimethylsilyl-1-propyne) and their stabilization by adding poly(1-phenyl-1-propyne)

The chromatographic and adsorption properties of poly(1-trimethylsilyl-1-propyne) (PTMSP), a high permeable glassy polymer, were studied in the course of long-term usage of the Chromosorb P NAW+10wt% PTMSP adsorbent on a packed column in the temperature range of 30–180°C. The structural changes in PTMSP related to a decrease in free volume and partial oxidation of the polymer were shown to substantially affect the adsorbent's properties. After the first 1.5 years (7000h) of the column operation, the elution order of compounds changed, peak symmetry and efficiency of the column increased, the retention parameters as well as heats of adsorption of light hydrocarbons showed considerable changes. In order to stabilize the chromatographic properties of PTMSP, another disubstituted polyacetylene, poly(1-phenyl-1-propyne) (PPP), was added to the initial polymer, and a new mixed stationary phase, 97% PTMSP+3% PPP, was obtained and characterized. The resulting adsorbent, Chromosorb P NAW+10wt% (97% PTMSP+3% PPP), is effective for solving a wide range of chromatographic problems, such as simultaneous detection of hydrocarbons and sulfur-containing inorganic gases, analysis of chlorine-substituted methanes in CCl4 and thiophene in benzene, separation of hydrocarbons and aromatic compounds. The chromatographic properties of the Chromosorb P NAW+10wt% PTMSP (97% PTMSP+3% PPP) adsorbent were shown to remain stable in the course of its long-term operation (for at least 1.5 years, or 7000h) on a packed column in the temperature range of 30–180°C.

Transformation of sulfur during pyrolysis of inertinite-rich coals and correlation with their characteristics

Sulfur transformation of inertinite-rich coals, which were sampled from three Western China coal mines, Xinjiang Hami (HM), Ningxia Lingwu (LW) and Shendong (SD), during pyrolysis is studied through measuring the release of H2S and COS gases by gas chromatography with flame photometric detector and through analyzing the sulfur forms in raw coals and chars from pyrolysis by X-ray absorption spectroscopy (XAS). It is revealed that the transformation of sulfur during coal pyrolysis is closely linked with coal properties, such as the vitrinite/inertinite ratio, alkaline mineral contents (especially calcium compounds) and H/C atomic ratio for three inertinite-rich coals. Comparisons are performed with a coal sample taken from Pingsuo (PS) coal mine located in North China, of which the properties are significantly different. The maximal release temperature of sulfur-containing gases for the pyrolysis of inertinite-rich coal is higher than that of the PS coal. The release of the S-containing gases in inertinite-rich coals has a maximal temperature interval around 600°C and this is associated with the conversions of inorganic sulfur species, such as pyrite transforming to FeS observed by the XAS in chars of these coals. During the process of pyrolysis, the organic sulfur compounds in inertinite-rich coal can be oxidized to form sulfoxide-like species due to the decomposition of oxygen-containing function groups in the coal matrix, but the active sulfur in PS coal can react with fresh char to form relatively stable thiophene structures. The formation of COS during the pyrolysis of inertinite-rich coals is mainly due to secondary reactions between H2S with CO and/or CO2.

Sulfur-Doped Graphene via Thermal Exfoliation of Graphite Oxide in H2S, SO2, or CS2 Gas

Doping of graphene with heteroatoms is an effective way to tailor its properties. Here we describe a simple and scalable method of doping graphene lattice with sulfur atoms during the thermal exfoliation process of graphite oxides. The graphite oxides were first prepared by Staudenmaier, Hofmann, and Hummers methods followed by treatments in hydrogen sulfide, sulfur dioxide, or carbon disulfide. The doped materials were characterized by scanning electron microscopy, high-resolution X-ray photoelectron spectroscopy, combustible elemental analysis, and Raman spectroscopy. The ζ-potential and conductivity of sulfur-doped graphenes were also investigated in this paper. It was found that the level of doping is more dramatically influenced by the type of graphite oxide used rather than the type of sulfur-containing gas used during exfoliation. Resulting sulfur-doped graphenes act as metal-free electrocatalysts for an oxygen reduction reaction.

Non-selenization method using sputtering deposition with a CuSe2 target for CIGS thin film

A novel method is proposed to prepare polycrystalline Cu(In,Ga)Se2 (CIGS) thin films by using a non-selenization method and a sputtering process with In, Ga and CuSe2 alloy targets. An annealing process in a furnace and rapid thermal annealing (RTA) at 400 °C without any selenium-/sulfurcontaining gas formed CIGS chalcopyrite (112), (220)/(204), and (312)/(116) phases. The major electrical and optical properties of the annealed thin films were superior to the required or reported values with 2.33 × 103 S/cm conductivity, 4.43 × 1020 cm−3 carrier concentration, 34.30 cm2/Vs hole mobility, and 2.41 × 106 cm−1 absorption coefficient.

Emission characteristics of nitrogen- and sulfur-containing odorous compounds during different sewage sludge chemical conditioning processes

Chemical conditioners are often used to enhance sewage sludge dewaterability through altering sludge properties and flocs structure, both affect odorous compounds emissions not only during sludge conditioning but also in subsequent sludge disposal. This study was to investigate emission characteristics of ammonia (NH3), sulfur dioxide (SO2), hydrogen sulfide (H2S) and carbonyl sulfide (COS) generated from sewage sludge conditioned by three representative conditioners, i.e., organic polymers, iron salts and skeleton builders, F-S (Fenton's reagent and skeleton builders) composite conditioner. The results demonstrate that polyacrylamide (PAM) has an insignificant effect on emission characteristics of nitrogen- and sulfur-containing odorous compounds, because the properties, sulfur and nitrogen speciations are similar in PAM-conditioned sludge and raw sludge (RS). Significant increases of SO2 and H2S emissions in the H2SO4 conditioning process were observed due to the accelerated decomposition of sulfur-containing amino acids in acidic environment. Fenton peroxidation facilitates the formation of COS. CaO can reduce sulfur-containing gases emission via generation of calcium sulfate. However, under strong alkaline conditions, free ammonia or protonated amine in sludge can be easily converted to volatile ammonia, resulting in a significant release of NH3.

Research on Corrosion and Monitoring Methods of Pressure Vessels in Sulfur-Containing Natural Gas Purification Plants

Pressure vessels in high sulfur-containing natural gas purification plants are likely corroded in acid media. Corrosion monitoring and control must be carried out to ensure safety and efficiency of purification system. So corrosion cause and service characters of pressure vessels in the purification plants were analyzed in this paper. The factors which influence pressure vessels corrosion include acid gas load, flow rate, phase state, temperature, heat-stable salts and degradation products. Then adaptability, advantages and disadvantages of the methods such as weight loss hanging slice method, electrochemical monitoring, ultrasonic thickness measurement, etc. were also analyzed in the paper. The results show that current on - line corrosion monitoring methods are hard to be applied in high sulfur-containing natural gas purification plants. Weight loss hanging slice method is an effective approach for pressure vessels corrosion monitoring. The data obtained are reliable and the investment is relatively lower. Based on characteristics of different technology units, corrosion coupon monitoring scheme is established. The research result provides a solid base for ensuring safe operation of high sulfur-containing natural gas purification plants.

Sulfur Transfers from Pyrolysis and Gasification of Coal

The sulfur transformation during pyrolysis and gasification of three kinds of coals was studied and the release of H2S and COS during the process was examined. During pyrolysis, besides the property of coal, reaction temperature is the most important factor that affects the sulfur removal. The main sulfur-containing gases is H2S, the ratio of sulfur-containing gases amount to total sulfur amount in coal reaches 25.8% for LS coal, 31.8% for YT coal and 13.1% for HJ coal, respectively. During CO2 gasification, compared with pyrolysis and steam gasification, there are more COS and less H2S formation, because CO could react with sulfide to form COS. During steam gasification, only H2S formation and no COS detected, because H2 has stronger reducibility to form H2S than CO. And the formation rate of sulfur during gasification is consistent with the gasification reactivity of three coal chars, indicated that coal rank is the major factor which affects the sulfur distribution during gasification.

Burst Strength Prediction of OCTG

With high pressure high temperature (HPHT) oil &amp; gas wells increasing, oil country tubular goods (OCTG) service environment tends to be critical complex. In these critical oil &amp; gas wells, when burst failures of high strength service grades for downhole applications once take place, the H2S gas may be run freely between tubing and intermediate casing, intermediate casing and surface casing, even the sulfur-containing gases spring ground, the harm is self-evident. Therefore, an accurate prediction of the burst strength, which is defined as the maximum value of internal pressure required to cause the steel casing to fail, is a very important consideration in the casing design process. The burst model has been provided in ISO/TR10400:2007, but almost half of the predictionts exceed the test burst strength. So this paper develops a new model that incorporates the influence of yield-to-tensile strength ratio on burst failure of casing and tubing without defects.

Field technology for desulfurization of associated petroleum gas

Applicability of gas desulfurization technologies for sulfur-containing gases under conditions of the limited choice is analyzed. Data on efficiency of a new process for catalytic desulfurization of sulfur-containing gases through H2S and RSH conversion in sulfur and disulfides, respectively, is demonstrated. The technology is approved in pilot projects of gas desulfurization at a flare line, on a gas-processing plant. The equipment is developed and certificated. Installations for catalytic desulfurization are intended to be equipped with a complete set of blocks for gas preparation and power-generating equipment directly at deposits. This solution substantially decreases both capital and operational expenditures compared to the traditional multi-stage absorption/desorption technologies such as expensive Claus process.

Application of bacterial-chemical oxidation for processing of nickel-containing raw materials

The results of investigations into processing the nickel-containing ores and concentrates (the sulfide copper-nickel ore of the Shanuch deposit, the nickel-pyrrhotine concentrate of the Talnakh processing plant, and the silicate nickel ore) with the use of microorganisms of immobilized bacteria as surfactants for autoclave leaching and bacterial iron-containing solutions for the utilization of sulfur-containing gases of pyrometallurgic production are presented. The influence of the presence of flotation reagents and nickel ions on the oxidizing activity of biomass is investigated. The combined production flowcharts of processing nickel-containing raw materials applying the bacterial-chemical oxidation are developed.