Pressure Of Hydrogen Sulfide Research Articles

Corrosion of Q125 Pipe Steel in Model Stratal Water for Different Temperatures and Pressures of Hydrogen Sulfide and Carbon Dioxide

Corrosion of Q125 Pipe Steel in Model Stratal Water for Different Temperatures and Pressures of Hydrogen Sulfide and Carbon Dioxide

Investigating equilibrium in the system of a hydrogen sulfide-quinhydrone absorbing solution

This paper reports a study into the influence of sodium carbonate concentration (10, 30, and 50 kg/m3) in the simultaneous presence of sodium thiosulfate (250 kg/m3) and quinhydrone (5 kg/m3) on the coefficient of the phase distribution of hydrogen sulfide in a quinhydrone absorbing solution. The research was carried out at the laboratory installation using chemical analysis methods of liquid and gas phases. It has been found that the coefficient of phase distribution increases dramatically with an increase in the degree of saturation of the quinhydrone solution with hydrogen sulfide. At the same time, in the presence of sodium thiosulfate in quinhydrone absorbing solutions, the coefficient of phase distribution increases compared to carbonate solutions of the same concentration. Thus, the partial hydrogen sulfide pressure over a quinhydrone solution at low degrees of hydrogen sulfide saturation (up to 3 %) is 5...10 times larger than that over soda solution, while at high degrees (60...80 %) it is almost the same. It can be argued that at the high concentrations of sodium carbonate and the degree of the saturation of quinhydrone solution with hydrogen sulfide the effect of sodium thiosulfate on the partial pressure of hydrogen sulfide decreases. An equation of the effect exerted by the NaНS concentration and the starting Na2CO3 concentration on the H2S partial pressure over quinhydrone solutions has been proposed. Based on the experimental studies' results, the equilibrium constant values for a hydrogen sulfide chemisorption reaction involving a quinhydrone solution have been calculated. To ensure the high absorption capacity, the process of hydrogen sulfide chemisorption should be carried out using solutions with a maximum concentration of sodium carbonate, 40...50 kg/m3. The presence of ballast components (Na2S2O3, NaHCO3) slightly reduces the sorption capacity of an absorbing solution. The results obtained could be used in engineering calculations and when developing technology for purification of fuel gases from hydrogen sulfide by a quinhydrone method.

ПОКАЗНИКИ СІРКОВОДНЕВОЇ РОТОРНО-ПОРШНЕВОЇ РОЗШИРЮВАЛЬНОЇ МАШИНИ У СКЛАДІ ЕНЕРГОТЕХНОЛОГІЧНОЇ УСТАНОВКИ

The article discusses the efficiency of applying a 12RPE-4,4/1,75 rotary-piston engine as an expansion machine for a promising energy technology plant for the production of hydrogen sulfide from the depths of the Black Sea. In this installation, high-pressure hydrogen sulfide is used in the expansion machine to produce mechanical energy, which can ensure the operation of pumps and other equipment. 12RPE -4,4/1,75 is a 12-cylinder short-stroke engine with an S/D ratio of 0.4. A feature of the engine is that for the distribution of the working fluid are used inlet and outlet openings, the overlap of which is carried out by the central rotor. Thus, the central rotor performs the function of a slide valve and a housing in which the pistons move. The use of the spool distribution provides a simple and compact design. The pressure of hydrogen sulfide at the inlet to the rotary-piston expansion machine is determined in the range of pipeline immersion depths of 0...1000 m, at a temperature of 280 ... 285 K and gas content of hydrogen sulfide in seawater 0.0...10.0 m3/m3. The definition of the main parameters of the working fluid and the working process is performed for a daily production of seawater of 100 m3/day. It is calculated that for a gas content of 2.5 m3/m3 with a depth of immersion of the lifting pipeline H = 250...1000 m, the power of the expansion machine is 0.20...0.61 kW, for gas content 5 m3/m3 – 0.65...0.86 kW for gas content 7.5 m3/m3 – 1.20...1.87 kW, for gas content 10 m3/m3 – 1.65...2.55 kW. Indicator diagrams of the expansion machine operation depending on the gas content of hydrogen sulfide in seawater and the depth of immersion of the pipeline were obtained. It was determined that with an increase in pressure at the inlet, the effective efficiency of the hydrogen sulfide expansion machine lies within 0.21...0.49. Also, with an increase in inlet pressure, the specific effective consumption decreases from 51.5 to 25.17 kg/kWh. Low values of specific effective consumption of hydrogen sulfide and high values of effective efficiency are due to the design features of the rotary-piston expansion machine, which combines the advantages of the piston and rotary engines.

Fabrication of Non-Vacuum Sns Thin Film for Solar Cell Application

Tin mono-sulfide (SnS) thin film has been investigated as a photovoltaic absorber material due to not only a high optical absorption coefficient but also non-toxicity and earth abundance. However, the highest photovoltaic conversion efficiency is as low as 4.4%. One of the reasons for the low efficiency is considered to be the poor quality of the SnS layer, such as the formation of secondary phases and a high grain boundary density. Thus, many research groups have dedicated their own effort to obtaining a high quality of SnS thin film. Nano-particle based approach can be one of the suitable fabrication methods of SnS thin films because the thin film can be prepared by a simple coating process using the nano-particle based ink, and the subsequent thermal annealing. The thermal annealing can transform the nano-particle precursors into the thin film and promote the grain growth. Moreover, it can affect the micro-crystalline structure of the thin film. Thus, we can control the physical properties of the SnS thin films by the modification of the thermal annealing condition. In this study, we focused on the effect of the thermal annealing condition on the properties of the SnS thin films. We have found that the crystallinity and band gap (Eg) of thin film are highly dependent on the thermal annealing temperature. The partial pressure of hydrogen sulfide (H2S) gas during the thermal annealing affects the valence of Sn atom and the composition of the thin film. Finally, we demonstrate a SnS thin film solar cell and characterize its photovoltaic performance.

Corrosion and Hydrogenation of 09G2S Steel in Hydrogen-Sulfide Media at Elevated Temperatures and Pressures

We study the influence of the partial pressure of hydrogen sulfide (1–5 atm) and temperature (25–120°C) on the corrosion behavior of 09G2S steel in model seawater and the degree of its hydrogenation. It is shown that the increase in the partial pressure of hydrogen sulfide (p H2S) up to 5 atm at 80°C leads to an increase in the corrosion rate of steel by almost an order of magnitude. It is shown that, for p H2S = 1–5 atm, hydrogen sulfide promotes the hydrogenation of steel. In this case, the amount of diffusion-mobile hydrogen is 3.5–3.7 times smaller than the amount of hydrogen with a higher energy of bonding with the metal. It is established that, the increase in temperature from 25 up to 120°C leads to a decrease in the corrosion rate of steel in model seawater for p H2S = 1 atm by a factor of ~ 6–8, whereas the degree of hydrogenation becomes 2.8–4.1 times larger.

Influence of environmental parameters on corrosion mechanisms of steels used in oil field

The influence of several environmental parameters on NACE SSC A tests results was analysed in this study. The effect of dissolved oxygen, pH and partial pressure of hydrogen sulfide (H2S) on corrosion and cracking susceptibility has been experimented. These experiments were done on steel wires used in oil industry. Experiments have proved that the pH value is the most influential parameter on both corrosion and cracking susceptibility of samples. H2S partial pressure also has a negative effect on cracking susceptibility. The dissolved oxygen content appeared as an incriminating factor on corrosion but can reduce the cracking susceptibility of samples.

Comparison of tensile and impact behavior of carbon steel in H2S environments

The present research reports the effect of hydrogen sulfide pressure on the tensile and impact behavior of carbon steel. Hydrogen content measurement was conducted due to the relationship between hydrogen and mechanical behavior. A remarkable increase in the relative tensile strength and plasticity loss was observed as hydrogen sulfide pressure increased. However, the Charpy absorbed energy showed no obvious change with increase of H2S pressure from 0.1MPa to 1.6MPa, even though a significant decrease compared to that of as-received steel. Combined with the results of hydrogen content measurement, it was found that hydrogen has a profound effect on the tensile and impact behavior of steel. Fractography of the corroded tensile and impact specimens exhibited mixed ductile–brittle rupture. In addition, the brittle zone on the fracture surface increased for corroded tensile specimens and showed nearly similar area fraction for corroded impact specimens as H2S pressure increased. A probable mechanism is proposed to interpret the difference in the tensile and impact results.

Phase equilibria of hydrogen sulfide and carbon dioxide simple hydrates in the presence of methanol, (methanol + NaCl) and (ethylene glycol + NaCl) aqueous solutions

This work aims at reporting the dissociation pressures of hydrogen sulfide and carbon dioxide simple hydrates in the presence of methanol, (methanol + NaCl) and (ethylene glycol + NaCl) aqueous solutions at different temperatures and various concentrations of inhibitor in aqueous solution. The equilibrium results were generated using an isochoric pressure-search method. These values are compared with some selected experimental data from the literature on the dissociation conditions of hydrogen sulfide and carbon dioxide simple hydrates in the presence of pure water to show the inhibition effects of the above mentioned aqueous solutions. Comparisons are finally made between our experimental values and the corresponding literature data. Some disagreements among the literature data and our data are found.

Effects of Sodium Chloride Concentration on Mild Steel Corrosion in Slightly Sour Environments

Abstract A research project was conducted to investigate the effect of a high salt concentration on corrosion from low partial pressures of hydrogen sulfide (H2S). The main objective was to study i...

Combined Effect of Carbon Dioxide, Hydrogen Sulfide, and Acetic Acid on Bottom-of-the-Line Corrosion

Abstract This research work presents a study of the combined influence of the partial pressure of hydrogen sulfide (H2S) and the concentration of free acetic acid (CH3COOH) on the general and localized carbon dioxide (CO2) corrosion at the bottom of the line. Experiments were carried out for up to 21 days in three 4-in (101.6-mm) internal diameter flow loops at 70°C with 2 bars of CO2. The flow regime was stratified for all of the experiments. It was found that trace amounts of H2S (from 0.004 bar to 0.13 bar) greatly retards the CO2 corrosion with general corrosion rates usually 10 to 100 times lower than their pure CO2 equivalent. However, the most protective conditions were observed at the lowest partial pressure of H2S, while corrosion increased when more H2S was added. The presence of a mackinawite film on the coupon surface seems to be the origin of this protectiveness. When 1,000 ppm of free acetic acid was added to the system, the general corrosion rate doubled compared with a baseline CO2 environ...

Model to Predict Internal Pitting Corrosion of Oil and Gas Pipelines

Abstract A model has been developed to predict internal pitting corrosion of oil and gas pipelines. This model is based on experiments carried out in the laboratory at high pressure and high temperature under the operating conditions of the oil and gas pipelines. There are two kinds of inputs: construction (pipe diameter, pipe wall thickness, and pipe inclination) and operational (production rates of oil, water, gas, solid, temperature, total pressure, partial pressures of hydrogen sulfide [H2S] and carbon dioxide [CO2], concentrations of sulfate, bicarbonate, and chloride). The model accounts for the statistical nature of the pitting corrosion, predicts the growth of internal pits based on the readily available operational parameters from the field, includes the pit growth rate driven by variables not included in the model, considers the variation of the pitting corrosion rate as a function of time, and determines the error in the prediction. The validity of this model was checked using data obtained fro...

Solubility of Hydrogen Sulfide in Aqueous Solutions of Piperazine in the Low Gas-Loading Region

The solubility of hydrogen sulfide in 2 m (about 0.146 mass fraction) aqueous solutions of 1,4-diazacyclohexane (piperazine, PIPH2) was measured at low gas loadings (at stochiometric molar ratios of hydrogen sulfide to PIPH2 between about 0.14 and 1.04) and low partial pressures of hydrogen sulfide (from about (1.3 to 98.7) kPa) at (313.5 and 392.2) K by headspace gas chromatography. The new experimental results are a supplement to previously published data in the high gas-loading region. The new experimental data are compared to prediction results from a thermodynamic model that was based only on gas solubility data in the high gas-loading area. That thermodynamic model for describing the vapor−liquid equilibrium uses Pitzer’s molality-based equation for the excess Gibbs energy of the aqueous solution. The average relative deviation between the new experimental results and the predictions for the partial pressure of hydrogen sulfide amounts to 10 %.

Correlating Sulfur Poisoning of SOFC Nickel Anodes by a Temkin Isotherm

Experimental data on sulfur's impact on solid oxide fuel cell (SOFC) nickel anodes have been analyzed using an isotherm for the sulfur coverage on the Ni surface: θ s = 1.45 - 9.53 X 10 -5 T+ 4.17 X 10 -5 T ln Y, where Y is the ratio between the partial pressures of hydrogen sulfide and hydrogen. The loss of performance, P l , of the SOFC can be correlated by P l = k*(θ s - θ min ), where θ min > 0 depends on the current density and anode material. The data range covered is 700-1000°C, concentration of hydrogen sulfide 0.05-50 ppm.

Heavy oil hydroprocessing over supported NiMo sulfided catalyst: An inhibition effect by added H 2S

The influence of H 2S (0–559.6 kPa) on Maya crude hydrotreating is investigated in an integral fixed bed up-flow micro reactor. The added H 2S inhibits hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) while asphaltene conversion (HDAs) remained almost unaffected. On the other hand, a promotional effect is found for hydrodemetallization (HDM). The observed variation in HDS and HDM conversions suggests a dual nature of catalytic sites particularly at high partial pressure of hydrogen sulfide. The promotional effect for HDM may be interpreted in terms of adsorption of metal–porphyrins on Brönsted acid sites (sulfhydryl group), which enhance hydrogenation of metal–porphyrins and convert them into the corresponding metal–chlorin structure in a first step of reaction. The final step in the HDM is essentially hydrogenolysis (metal–nitrogen) and requires the presence of an anionic vacancy (CUS). The conversion of asphaltene is also depending on the acidic nature of sulfided catalyst that is remaining either uninhibited or slightly enhanced with H 2S.

Rapid synthesis of 2,5‐disubtituted 1,3,4‐thiadiazoles under microwave irradiation

AbstractThe one pot, three‐components condensation of aromatic aldehydes, hydrazine and sulfur in ethanol under microwave irradiation provided symmetrically 3,5‐disubstituted 1,3,4‐thiadiazoles in high yields and good purity. This reaction must be conducted under pressure of hydrogen sulfide produced in‐situ. The structure of the compounds was confirmed by 1H, 13C NMR, MS and elemental analysis.

Addition of hydrogen sulfide to methyl acrylate over solid basic catalysts

H 2S was added to methyl acrylate in a batch reactor at 313 K, 450 rpm, 0.2 M (in decane) in methyl acrylate, 5.5 bar of hydrogen sulfide pressure in the presence of solid bases. The bases differed in their chemical composition, structural properties, and acid–base properties. The bases were cation-exchanged X-faujasites, magnesium oxide, alkaline- and alkaline-earth-doped magnesium oxides, and commercially available and synthesized mixed magnesium/aluminum oxides. All of these catalysts were shown to achieve, in terms of both activity and selectivity, the addition of H 2S to methyl acrylate as compared with the patent literature. Catalytic runs have also been conducted on a fixed-bed continuous-flow reactor with performances, in terms of selectivity, better than those observed in batch mode, particularly with a Cs-exchanged X zeolite, which featured a selectivity level similar to that of modified ion-exchange resins. As previously assumed from kinetics and IR studies on H 2S and methyl acrylate adsorption and co-adsorption, the prerequisite for the title reaction to occur is the dissociation of H 2S into HS − and H + species over weak acid/strong basic Lewis pair sites. This assumption is confirmed in this work and is in agreement with the HSAB principle; H 2S is dissociated into a soft HS − nucleophilic species associated with a soft M x+ acid, and the hard H + species is associated with the hard O 2− basic species.

Hydrodesulfurization and hydrogenation reactions on noble metal catalysts: Part II. Effect of partial pressure of hydrogen sulfide on sulfur behavior on alumina-supported platinum and palladium catalysts

Hydrodesulfurization (HDS) reactions of the 35S radioisotope-labeled dibenzothiophene (DBT) were carried out over 10% Pd/Al 2O 3 and 2% Pt–10% Pd/Al 2O 3 catalysts. The total amount of the sulfur ( S total) accommodated on the catalysts and the amount of labile sulfur ( S 0) participating in the HDS reaction were determined using a 35S radioisotope tracer method. The sulfided state of noble metal sulfides on two catalysts changed depending on the partial pressure of H 2S in the reaction atmosphere. Taking into account the amount of the sulfur accommodated on the alumina support, the sulfided Pt or Pd species on the catalysts are presented in the form of PdS x or PtS x ( x=0–0.25) in lower partial pressures of H 2S under 5.2 kPa. At the same time, all the sulfur incorporated into the catalyst were almost the labile sulfur. On the other hand, the sulfur further incorporated into the Pd catalyst with further increasing the partial pressure of H 2S in a reaction system over 5.8 kPa, resulting in the formation of the phase of PdS. In contrast, there was no significant change in both S total and S 0 even though the partial pressure of H 2S in the atmosphere increased into ca. 17 kPa in the case of Pt–Pd catalysts. The structures of PdS 0.25 and PtS 0.25 in the Pt–Pd catalyst remained.

Prediction of the vapor–liquid phase equilibrium of hydrogen sulfide and the binary system water–hydrogen sulfide by molecular simulation

NVT- and NpT-Gibbs ensemble Monte Carlo simulations were carried out in order to calculate the vapor–liquid phase equilibrium of hydrogen sulfide (between 203 and 363 K) and of the binary system hydrogen sulfide–water (between 313 and 433 K). Furthermore, the properties of supercritical hydrogen sulfide were determined at pressures between 0.1 and 100 MPa in the temperature range from 383 K to 423 K by NpT-Monte Carlo simulations. Molecular interactions were described using effective pair potential models together with common mixing rules, without any adjustable binary interaction parameters. Good agreement between simulation results and experimental data was found. Simulation of the binary system shows liquid-liquid equilibrium at temperatures below 393 K when pressures are above the vapor pressure of hydrogen sulfide.

Fitness-for-Purpose Material Testing for Sour Gas Service—An Overview

Abstract Sour environments differ significantly in their aggressiveness toward materials, depending on such factors as total system pressure, partial pressures of hydrogen sulfide (H2S) and carbon dioxide (CO2), pH of the aqueous phase, temperature, chloride ion (Cl−) concentration, etc. Materials that perform poorly in standard laboratory sulfide stress cracking and hydrogen-induced cracking tests and some field environments may give acceptable performance under other sour service conditions. This paper provides some additional guidance on the manner in which standard sour service testing methods should be selected and performed, and on the interpretation and application of the results. The relevant recommendations and requirements of NACE International, the European Federation of Corrosion (EFC), and the American Petroleum Institute (API) are reviewed. The recommendations of NACE, EFC, and API for the selection of the most appropriate test method(s), test frequency, and acceptance criteria for particula...

Corrosion Behavior of Aluminum Alloys in the Presence of Hydrogen Sulfide

The corrosion–electrochemical behavior of both carbon steel and aluminum alloys in hydrogen sulfide-bearing mineralized media is considered. An increase in the partial pressure of hydrogen sulfide aggravates the catastrophic breakdown of carbon steel, yet diminishes both the corrosion rate and the localization of corrosion attack on aluminum alloys. An investigation of the nature of the nonstoichiometry of surface oxide films on both carbon steel and aluminum alloys with the use of photoelectric-recombination method, revealed that the films fundamentally differ in semiconductive properties, according to which hydrogen sulfide can either promote or inhibit the corrosion. That is why hydrogen sulfide oppositely affects the corrosion–electrochemical behavior of aluminum alloys and carbon steels.