Partial Pressure Of Hydrogen Sulfide Research Articles

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.

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.

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.

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.

Kinetic study of the hydrogen sulfide effect in the conversion of thiophene on supported Co-Mo catalysts

The hydrodesulfurization of thiophene on a commercial CoMo/alumina catalyst was studied in a Berty type CSTR reactor at 350°C, with partial pressures of hydrogen sulfide in the range of 0.2 to 5.5 bar. A kinetic model with interconversion of active sites is superior to models based on a fixed number of active sites. The proposed mechanism for the interconversion of active sites predicts that the hydrogenation and hydrogenolysis activities of a HDS catalyst can be substantially varied by hydrogen sulfide. The model also explains the controversial hydrogen sulfide effects observed in various types of reactions on CoMo catalysts.

Kinetic study of the hydrogen sulfide effect in the conversion of thiophene on supported CoMo catalysts

The hydrodesulfurization of thiophene on a commercial CoMo/alumina catalyst was studied in a Berty type CSTR reactor at 350°C, with partial pressures of hydrogen sulfide in the range of 0.2 to 5.5 bar. A kinetic model with interconversion of active sites is superior to models based on a fixed number of active sites. The proposed mechanism for the interconversion of active sites predicts that the hydrogenation and hydrogenolysis activities of a HDS catalyst can be substantially varied by hydrogen sulfide. The model also explains the controversial hydrogen sulfide effects observed in various types of reactions on CoMo catalysts.

Effect of structure and strength on the corrosion resistance of corrosion-resistant steels and alloys in media containing hydrogen sulfide and chlorine ions

Equipment in gas and oil wells comes in contact with media, whose aggressiveness is determined by the chlorine-ion content, the partial pressure of hydrogen sulfide and carbon dioxide gas, and temperature. Hydrogen sulfide corrosion cracking (HSCC), pitting, and general corrosion are basic forms of corrosion failure in these inedia. In a number of cases, special structural steels, whose corrosion resistance can be enhanced with inhibition of the medium, are used in fabricating the equipment. Corrosion-resistant steels should be employed when inhibition is inapplicable, and, in addition to HSCC, the development of pitting and general corrosion is possible during service. The resistance of austenitic, austenitic -ferritic, and rnartensitic steels to HSCC and pitting are investigated in this paper.

Solubility of Hydrogen Sulfide in Water + Monoethanolamine + 2-Amino-2-methyl-1-propanol

Alkanolamine aqueous solutions are widely used in gas treating processes to remove acid gases, such as CO[sub 2] and H[sub 2]S, from natural, refinery, and synthesis gas streams. The solubilities of hydrogen sulfide in water (1) + monoethanolamine (2) + 2-amino-2-methyl-1-propanol (3) have been measured at 40, 60, 80, and 100 C and at partial pressures of hydrogen sulfide ranging from 1.0 to 180 kPa. The ternary mixtures studied were [omega][sub 2] = 0, [omega][sub 3] = 0.3; [omega][sub 2] = 0.06, [omega][sub 3] = 0.24; [omega][sub 2] = 0.12, [omega][sub 3] = 0.18; [omega][sub 2] = 0.18, [omega][sub 3] = 0.12; and [omega][sub 2] = 0.24, [omega][sub 3] = 0.06 where [omega] is the mass fraction. The model of Kent and Eisenberg has been extended to represent the solubility of H[sub 2]S in the ternary mixtures. The model reasonably reproduces the equilibrium partial pressure of H[sub 2]S above the ternary mixtures, not only over a temperature range from 40 to 100 C, but also at various compositions of the components in the ternary mixture.

Solubility of hydrogen sulfide in aqueous mixtures of monoethanolamine with N-methyldiethanolamine

Alkanolamine aqueous solutions are frequently used for the removal of acidic gases, such as CO[sub 2] and H[sub 2]S, from gas streams in the natural gas and synthetic ammonia industries and petroleum chemical plants. The solubilities of hydrogen sulfide in aqueous mixtures of monoethanolamine (MEA) with N-methyl-diethanolamine (MDEA) have been measured at 40, 60, 80, and 100C and at partial pressures of hydrogen sulfide ranging from 1.0 to 450 kPa. The mixtures of alkanolamines studied are 4.95 kmol/m[sup 3] MEA, 3.97 kmol/m[sup 3] MEA + 0.51 kmol/m[sup 3] MDEA, 2.0 kmol/m[sup 3] MEA + 1.54 kmol/m[sup 3] MDEA, and 2.57 kmol/m[sup 3] MDEA aqueous solutions. The solubilities of hydrogen sulfide in aqueous alkanolamine solutions are reported as functions of the partial pressure of hydrogen sulfide at the temperatures of 40-100C.

Solubility of hydrogen sulfide in mixtures of N-methylpyrrolidone with alkanolamines

Murrieta-Guevara F., Rebolledo-Libreros E. and Trejo A., 1992. Solubility of hydrogen sulfide in mixtures of N-methylpyrrolidone with alkanolamines. Fluid Phase Equilibria, 73: 167-174. The solubility of hydrogen sulfide in binary mixtures of N-methylpyrrolidone with monoethanolamine and diethanolamine was determined at temperatures between 298.15 and 373.15 K in the pressure range 20–1300 kPa. The mixtures studied were 15 wt.% with monoethanolamine and 30 wt.% with diethanolamine. The experimental results are reported as the partial pressure of hydrogen sulfide against its mole fraction in the liquid phase. Values of the enthalpy of solution were derived from the solubility data.

Prediction of critical environments for active-passive transition of corrosion resistant alloys in sour environments.

The corrosion behavior, in particular passivation, of corrosion resistant alloys (CRAs) in sour environments was investigated intensively by using a duplex stainless steel and an austenitic stainless steel as representative CRAs. It was found that hydrogen sulfide significantly retarded the passivation of CRAs, whereas carbon dioxide did not. The changes in corrosion morphologies due to the changes in environmental aggressiveness were classified on the basis of the immersion test results. A new criterion for predicting the critical environments for active to passive transition was proposed. The critical environments for the transition of a given alloy can be determined by comparing the pH of environments with the depassivation pH (pHd) of the material which is a function of environmental factors such as temperature and partial pressure of hydrogen sulfide. The locus of the points having pH=pHd gave a good estimation for the critical environments. It was confirmed that the prediction was in good agreement with the long-term immersion test results for 6 months. Since this criterion is based on the corrosion mechanism, it has many advantages; the prediction is accurate; the results for CO2-free environments can be extended to CO2-containing environments; and the prediction can be performed very quickly.

Evaluation of corrosion rates based on content of iron in drain water from atmospheric-vacuum pipestill units

The paper examines the types of iron compounds formed as corrosion products in primary crude oil processing. Metal losses by corrosion in units of the atmospheric-vacuum or atmospheric pipestill type are determined by the joint action of hydrogen chloride and hydrogen sulfide in the presence of condensed moisture. The main corrosion products are soluble iron(II) chlorides and insoluble iron(II) sulfides. The composition and properties of the sulfide films are determined by the partial pressure of hydrogen sulfide. As a result of tests conducted in a combination electric desalting and atmosphericvacuum pipestill unit, it was established that when neutralizing agents and a corrosion inhibitor were used, there was practically no dissolved iron in the drain water from the reflux tanks.