H2S In Natural Gas Research Articles

Integrated stable S isotope, microbial and hydrochemical analysis of hydrogen sulphide origin in groundwater from the Legnica-Głogów Copper District, Poland

Hydrogen sulphide (H2S) was first reported in 2010 in an underground mining area of the Legnica-Głogów Copper District (LGCD). However, during the deposit exploration and exploitation stage in 1970, H2S was not detected. Previous studies have not indicated the origin of H2S in LGCD mine waters. Indirect evidence has suggested that, most likely, H2S migrated with the groundwater from the Main Dolomite aquifer to the mine galleries through cracks in the separating anhydrite and halite layers resulting from long-term mining operations. Interdisciplinary studies have been conducted to confirm this hypothesis. Investigations of the δ34S in H2S of 12 groundwater samples taken from leakages from cracks in galleries and drilled boreholes showed high isotopic similarity to H2S in natural gas and S-organic compounds of oil from petroleum reservoirs in the Main Dolomite unit, where this gas was generated in high volumes mainly as a result of thermochemical sulphate reduction (TSR). Microbial investigations of mine water indicated the presence of Desulfitobacterales, Desulfobacterales, Desulfotomaculales, Desulfovibrionales, and Desulfuromonadia as possible indicators of contact between the analysed water and rocks inhabited by sulphur-reducing bacteria and Halothiobacillales, as an indicator of contact between water and salt. Hydrochemical analysis revealed that water flowing out of mine galleries and boreholes has a higher salinity than groundwater that is naturally associated with the horizon where mines operate; this phenomenon is associated with H2S occurrence. This investigation confirmed the hypothesis that the H2S in the LGCD mines originates mainly from the Main Dolomite aquifer. Furthermore, this study confirms that a multifaceted approach is necessary to answer complex geochemical questions in mining.

Desulfurization of ultra-low-concentration H2S in natural gas on Cu-impregnated activated carbon: Characteristics and mechanisms

Characteristics and mechanisms of low-concentration H2S (4.5 ppmv) removal in balanced CH4 were investigated for Cu-impregnated activated carbon (Cu/AC). Herein, breakthrough experiments and analysis of the changes in the state of Cu and sulfur species on Cu/AC during a cyclic experiment comprising desulfurization, regeneration, and re-desulfurization were conducted. During desulfurization, catalytic oxidation, sulfate formation, and reactive adsorption resulted in the formation of elemental sulfur, CuSO4, and CuS, respectively. CuO acted as the catalyst, oxygen donor, and reactive adsorption site for the reaction. At 303 K, the low- concentration H2S was removed mainly through catalytic oxidation and sulfate formation. As the temperature was increased to 333 K, reactive adsorption and sulfate formation were promoted. The reactive adsorption was crucial for the complete removal of low-concentration H2S. The deposited sulfur was removed via vaporization, dissociation, and oxidation. The oxidative treatment using a dilute O2 mixture resulted in the effective removal of the thermally stable sulfur species and active regeneration of CuO. Furthermore, oxidative regeneration contributed to the high dispersion of CuO and enhanced the reactive adsorption. During desulfurization and regeneration, CuSO4 was formed by consuming oxygen species, which necessitates the use of an effective removal method for ensuring the reusability of adsorbents.

Ultrafine Au nanoparticles confined in three-dimensional mesopores of MCM-48 for efficient and regenerable Hg0 removal sorbent in H2S and H2O containing natural gas

The H2O and H2S in natural gas are frequently deemed to have inhibitory influences on Hg0 removal performance of most noble metal based Hg0 absorbents, it is extremely significant to develop an efficient and regenerable Hg0 removal absorbent with excellent H2S and H2O tolerance. In the work, the Au/MCM-48 absorbent was controllable synthesized using a facile yet robust method for Hg0 removal in H2S and H2O containing natural gas. The ultrafine Au nanoparticles with a diameter of 1.4 nm were embedded and uniformly dispersed in the three-dimensional channels of MCM-48. The absorbent of 1 wt% Au achieved a complete Hg0 capture performance at 60,000 h−1 and 30 °C by forming Au-Hg amalgam, and its Hg0 adsorption capacity achieved to 7.23 mg∙g−1 at 5% breakthrough. The spent sample could be easily regenerated by thermal treatment without distinct degradation over 5 cycles. The introduction of H2S and H2O in gas flow had an inappreciable impact on Hg0 removal performance over the Au/MCM-48 absorbent. The excellent Hg0 adsorption efficiency, outstanding capture capacity and good regeneration performance of the absorbent due to the nano-confinement of MCM-48 channels, which prevents Au nanoparticles from growing and agglomerating. Excellent H2O tolerance is attributed to the good hydrophobicity of MCM-48 modified by trimethylchlorosilane, and the high H2S tolerance is due to the fact that the Au nanoparticles lack reactivity toward H2S. This work provides a promising method for the preparation of effective and regenerable absorbents for demercuration in H2S and H2O containing natural gas.

Manganese gluconate, A greener and more degradation resistant agent for H2S oxidation using liquid redox sulfur recovery process

Iron chelate liquid redox sulfur recovery (LRSR) has been one of the most frequently recommended technologies for the oxidation of H2S in natural gas into elemental sulfur, particularly when the acid gas has a high CO2/H2S molar ratio. The process is however known to suffer from extensive oxidative ligand degradation that results in high operational costs. Moreover, poor biodegradability or toxicity of the existing ligand has become a concern. In this research, we demonstrated that gluconate, a naturally greener ligand, when coupled with manganese as the metal, has considerable potential to be a better redox agent. Manganese gluconate solution was more resistant against ligand degradation compared with iron NTA. As required, aerated solution was capable of converting dissolved NaHS into elemental sulfur. At sufficiently high pH, manganese gluconate solutions were stable enough from precipitation of manganese hydroxide, carbonate, or sulfides. An equilibrium calculation has been developed to understand the precipitation behavior.

H2S chemical looping selective and preferential oxidation to sulfur by bulk V2O5

The concept of chemical looping is applied for the first time to selective oxidation of H2S to elemental sulfur. An oxygen carrier (OC) is exposed to cyclic reduction by H2S and oxidation by O2. The properties of bulk V2O5 as OC are explored for this reaction in the 150−200 °C temperature range. Steady cyclic behavior can be obtained with high selectivity towards elemental sulfur. Some undesired SO2 is formed during exposure to H2S but more significantly during re-oxidation of the OC. This indicates that bulk V2O5 does not completely oxidize the adsorbed H2S in the reductant step. Characterizations indicate that V4+ and V5+ species are mostly involved in the process. Preferential oxidation in presence of CH4 is confirmed on this OC. Although optimization needs to be done, the potential of chemical looping concept for direct preferential oxidation of H2S in natural gas and biogas is demonstrated.

Impacts of CO2 and H2S on the risk of hydrate formation during pipeline transport of natural gas

Evaluation of maximum content of water in natural gas before water condenses out at a given temperature and pressure is the initial step in hydrate risk analysis during pipeline transport of natural gas. The impacts of CO2 and H2S in natural gas on the maximum mole-fractions of water that can be tolerated during pipeline transport without the risk of hydrate nucleation has been studied using our novel thermodynamic scheme. Troll gas from the North Sea is used as a reference case, it contains very negligible amount of CO2 and no H2S. Varying mole-fractions of CO2 and H2S were introduced into the Troll gas, and the effects these inorganic impurities on the water tolerance of the system were evaluated. It is observed that CO2 does not cause any distinguishable impact on water tolerance of the system, but H2S does. Water tolerance decreases with increase in concentration of H2S. The impact of ethane on the system was also investigated. The maximum mole-fraction of water permitted in the gas to ensure prevention of hydrate formation also decreases with increase in the concentration of C2H6 like H2S. H2S has the most impact, it tolerates the least amount of water among the components studied.

Sulphur tolerance of Au-modified Ni/GDC during catalytic methane steam reforming

Au doping and high calcination temperatures improve the sulphur tolerance of Ni/GDC, a potential SOFC anode.

CO2/CH4 and H2S/CO2 Selectivity by Ionic Liquids in Natural Gas Sweetening

CO2 and H2S in natural gas usually lead to low caloric value and corrosion of the transportation pipeline, and hence, separating CO2/CH4, H2S/CH4, and H2S/CO2 is essential for natural gas purification, desulfurization, as well as gas regeneration and reutilization. Trapping H2S, CO2, and CH4 not only eliminates their environmental contamination, but also increases feedstocks for industrial production. In order to avoid the contamination and causticity problems caused by the conventional alkali absorbents, ionic liquids have been proposed as alternatives to absorb and separate different gases for decades. In this paper, the investigations of pure ionic liquids in the selective absorption of CO2/CH4, H2S/CH4, and H2S/CO2 are reviewed. Important influencing factors, including temperature, pressure, functionality, and properties of gas and ionic liquids, were analyzed. Ionic liquids with alkali groups on the cation and anion are promising CO2 and H2S solvents and competent separators for removing CO2 or/and H...

Genesis and distribution of hydrogen sulfide in deep heavy oil of the Halahatang area in the Tarim Basin, China

As the largest oil-and-gas-bearing basin in China, the Tarim Basin contains rich oil and gas resources buried deep underground. In recent years, large oil fields have been discovered in the Halahatang area of the northern Tarim Basin. The reservoir is buried 6000–7300 m underground. This reservoir is dominated by the Ordovician carbonate rocks, and the crude oil is mainly heavy oil. As a crude oil-associated gas, the natural gas generally contains hydrogen sulfide (H2S). The heavy oil in this region is the deepest buried heavy oil found in the world. H2S is also associated with the deepest buried natural gas. The burial, preservation and degree of biodegradation of a paleo-reservoir can be used to predict the distribution of H2S. According to research findings, there is a clear planar distribution pattern of H2S content: high in the east and north, and low in the west and south. We compared the physical properties of crude oil and the analysis of the composition of natural gas and isotopes, biomarker compounds of crude oil and groundwater. We find that the content of H2S in natural gas bears some relation to the physical properties and degree of biodegradation of crude oil. Crude oil density, sulfur content, colloid, and asphaltene have positive correlations with H2S content in natural gas. The formation of H2S is controlled by the degradation and densification of crude oil. Crude oil densification can lead to an increase of the sulfur content. The rise in the temperature of the reservoir resulting from the depth of burial causes the thermal decomposition of sulfur compounds to produce H2S. The generation of H2S by the thermal decomposition of sulfur compounds is confirmed by data on sulfur isotopes. The distribution of H2S can then be predicted based on the burial conditions of the paleo-reservoir and the degree of biodegradation. In the south Rewapu of the Halahatang area, the thick cap rock of the Ordovician oil reservoir was preserved well in the late Hercynian Period, without undergoing biodegradation. The oil is mainly normal oil and light oil. Sulfur content in the crude oil is quite low, making it impossible to generate a large amount of H2S in the later stages of deep burial.

天然气中H<sub>2</sub>S快速定量检测研究进展

H2S对天然气的运输、贮存及使用安全会产生破坏性的影响，其含量是天然气检测必不可少的项目，快速准确测定其含量具有极其重要的意义。本文对天然气中H2S检测所用到的国内国际标准进行了总结分析。在此基础上，综述了满足快速定量检测H2S的半导体氧化物、电化学和光学传感器研究进展，比较各种H2S检测传感器的操作标准(如操作原理、检测限、响应时间、检测浓度范围)。最后，探讨各种传感器的不足并指出今后的发展方向。 H2S has great effect on the transportation, storage and use safety of natural gas. It is an absolutely necessary measuring project for natural gas quality control. So it has important significance to quickly and precisely monitor H2S content. The summary is made about the present national and international standard test method for H2S in natural gas. Based on these, sensor-based type for quantifying H2S including semiconductor metal oxide, electrochemical and optical sensor are re-viewed. Different quality-assurance parameters (e.g., operating principles, limit of detection, re-sponse time and common operating range of concentration) are evaluated and compared. Finally, the limitations and the future prospects of these sensor-based methods are highlighted.

An isotope study of the accumulation mechanisms of high-sulfur gas from the Sichuan Basin, southwestern China

The mechanism of hydrogen sulfide (H2S) generation plays a key role in the exploration and development of marine high-sulfur natural gas, of which the major targets are the composition and isotope characteristics of sulfur-containing compounds. Hydrocarbon source rocks, reservoir rocks, natural gases and water-soluble gases from Sichuan Basin have been analyzed with an online method for the content of H2S and isotopic composition of different sulfur-containing compounds. The results of comparative analysis show that the sulfur-containing compounds in the source rocks are mainly formed by bacterial sulfate reduction (BSR), and the sulfur compounds in natural gas, water and reservoir are mainly formed by thermal sulfate reduction (TSR). Moreover, it has been shown that the isotopically reversion for methane and ethane in high sulfur content gas is caused by TSR. The sulfur isotopic composition of H2S in natural gas is inherited from the gypsum or brine of the same or adjacent layer, indicating that the generation and accumulation of H2S have the characteristics of either a self-generated source or a near-source.

Hydrogen sulfide reformation in the presence of methane

This paper provides experimental investigation on the potential of hydrogen production from hydrogen sulfide and methane mixtures in nitrogen. The reformation of H2S in natural gas represents a viable alternative option for the treatment of acid gases extracted from gas wells that contains H2S, CH4 and N2 in the gases without their separation, using for example, the amine process to remove H2S. A laboratory-scale quartz reactor was used to investigate experimentally the effect of temperature and inlet stream composition on the production of hydrogen from a mixture of hydrogen sulfide and methane diluted in nitrogen. The results reveal the important role of reactor temperature on the decomposition of both hydrogen sulfide and methane as well as the production of hydrogen. The results also showed that the production of hydrogen increased dramatically at temperatures exceeding 1473K wherein the conversion of hydrogen sulfide is more significant. The methane was consumed at temperatures above 1373K. The conversion of hydrogen sulfide in presence of methane was higher than that in case of hydrogen sulfide only. The carbon disulfide formed during the reformation process increased with increase in temperature. These results provide favorable reactor operational conditions for the reformation of methane with hydrogen sulfide. These results also provide a viable alternative option for the treatment of various waste streams containing hydrogen sulfide to produce clean hydrogen and sulfur.

Benefits of Jet Reactor Application in Alkaline Gas Purification

Our energy requirements have increased enormously in the last decades. We can get a significant amount of energy by the combustion of flammable gas mixtures of hydrocarbons. Proper gas purification prior to use is essential. A hydrocarbon-based gas mixture which contains sulfur compounds is called sour gas. H2S is one of the most problematic compounds in the transportation and utilization of natural gas or biogas. H2S is a toxic gas. It is corrosive in the presence of water. Upon the combustion of natural gas H2S is converted into SO2 which is not only harmful for the environment by causing acid rain but also constitutes a danger to human health. There are several methods of reducing the content of H2S in natural gas. However, the usability of these methods is limited due the increasingly strict environmental regulations. Our future aim is to develop a new, efficient and selective method. Selectivity is important to avoid unnecessary energy and chemicals consumption. Alkali-based competitive chemisorption method appears to be a good choice. H2S reacts with NaOH faster than CO2, which is the basis of the selectivity. Residence time is a key parameter for the efficiency of the operation. The essence of the method is the very short contact time, thus intensive contact between the gas and liquid phases has to be ensured along with rapid phase separation. Using a spray technology such as in Jet reactor is feasible. The advantage of the application of a Jet reactor is that various parameters can be changed.

Geochemistry Characteristics of Hydrogen Sulphide-Bearing Gas Pools in Sichuan Basin

Sichuan Basin is the oil and gas bearing basin that is discovered in China, with the most hydrogen sulfide gas pool and the greatest reserve. In this article, gas pools with high hydrogen sulfide in Sichuan Basin were taken as the object of study; the geochemistry characteristic of natural gas was systematically studied, and the origin of natural gas with hydrogen sulfide in Sichuan Basin was discussed. The hydrogen sulfide content in the hydrogen sulfide gas pools of Sichuan Basin is 0.6%–14.5%; the sulfur isotope values of hydrogen sulfide gas have a close relationship with the sulfur isotope values of anhydrite in the same reservoir, and the sulfur isotope fractionation between the anhydrite and the H2S is 4‰–14‰, showing that the H2S in natural gas and the anhydrite in reservoir have the same sulfur source, the H2S in natural gas is the product of TSR reaction. The relationship among the hydrogen sulfide content in the gas pool, the hydrogen isotope of methane and the sulphur isotope of hydrogen sulfide is not obvious; but the high hydrogen sulfide content corresponds to the heavier ethane carbon isotope composition, and the carbon isotope of carbon dioxide is lower than −10‰, which belongs to the organic origin and has further verified the fact of TSR occurrence in the reservoir. There is the phenomenon of carbon isotopic reversal of methane and ethane in some areas of the Huanglongchang gas field, Wubaiti gas field and Puguang gas field in the Northeast Sichuan as well as Weiyuan gas field in South Sichuan, which is mainly caused by the later period of cracking-based gas-production process of the crude oil. TSR has less influence on these gas pools.

Simulation Experiments on Thermochemical Origin of High H2S in Natural Gas

Thermal simulation experiments on thermochemical sulfate reduction system of natural gas and magnesium sulphate were carried out using an autoclave in the presence of water. The products were characterized by some advanced analytical methods. Thermodynamics and reaction kinetics of thermochemical sulfate reduction processes had been investigated on the basis of the experimental data. The results showed that thermochemical sulfate reduction of natural gas with magnesium sulphate could proceed at 425°C–525°C to produce magnesium oxide, carbon, hydrogen sulfide, and carbon dioxide as the main products. The reactions are thermochemically possible and high temperature is favored. Long-chain hydrocarbons more easily thermodynamically participate in the reactions than short-chain hydrocarbons. According to the reaction model, the calculated activation energy for the reaction between natural gas and magnesium sulfate is about 78.975 kJ/mol.

Industrial applications of new sulphur biotechnology

The emission of sulphur compounds into the environment is undesirable because of their acidifying characteristics. The processing of sulphidic ores, oil refining and sulphuric acid production are major sources of SO2 emissions. Hydrogen sulphide is emitted into the environment as dissolved sulphide in wastewater or as H2S in natural gas, biogas, syngas or refinery gases. Waste streams containing sulphate are generated by many industries, including mining, metallurgical, pulp and paper and petrochemical industries. Applying process technologies that rely on the biological sulphur cycle can prevent environmental pollution. In nature sulphur compounds may cycle through a series of oxidation states (-2, 0, +2, +4, +6). Bacteria of a wide range of genera gain metabolic energy from either oxidising or reducing sulphur compounds. Paques B.V. develops and constructs reactor systems to remove sulphur compounds from aqueous and gaseous streams by utilising naturally occurring bacteria from the sulphur cycle. Due to the presence of sulphide, heavy metal removal is also achieved with very high removal efficiencies. Ten years of extensive laboratory and pilot plant research has, to date, resulted in the construction of over 30 full-scale installations. This paper presents key processes from the sulphur cycle and discusses recent developments about their application in industry.

The effects of pressure and temperature on the catalytic oxidation of hydrogen sulfide in natural gas and regeneration of the catalyst to recover the sulfur produced

AbstractThe influence of pressure up to 5600 kPa and temperature up to 175 °C on the oxidation of low concentrations of H2S in natural gas was studied in a fixed bed reactor over an activated carbon catalyst. Operation of this system at 5600 kPa provides higher catalyst activity (virtually 100% H2S conversion) over a longer period of time and with lower selectivity to SO2 than when operated at atmospheric pressure. The desorption of sulfur from a loaded catalyst occurs first from the macropores (> 100 nm) of the catalyst which contain a substantial portion of the sulfur load and then from the micropores (< 100 nm). This study also indicated that the sulfur recovery process is both rapid and effective at 327°C.