Pressure Of Hydrogen Sulfide Research Articles

How to Pressurize Autoclaves for Corrosion Testing Under Carbon Dioxide and Hydrogen Sulfide Pressure

Abstract All the methods presently used for pressurizing autoclaves have advantages and disadvantages. Pressurizing with pure gases is undoubtedly the surest method, since it is insensitive to the autoclave filling rate, and the influence of temperature stability readily can be controlled. The only limitation is the impossibility of accurately reproducing very low hydrogen sulfide (H2S) partial pressures ( 150°C). Conventional pressurizing with gas mixtures is not at all practical, since it demands either excessively large autoclaves or the bubbling of prohibitive volumes of gas. To overcome these fundamental difficulties, alternative methods are proposed, such as high-temperature bubbling using a cooled reflux condenser or presaturation of the autoclave at 60°C at a fraction of the test pressure, enabling the latter to be attained during subsequent heating by the natural increase in pressure with temperature.

Structure of cadmium and lead sulfide nanoclusters in a matrix of a langmuir-blodgett film

Semiconducting materials in the form of nanoclusters distributed in an organic or silicate matrix are of interest to researchers engaged in the field of nanoelectronics and nonlinear optics. These materials involve cadmium, zinc, lead, and mercury chalcogenides in silicate glass or Langmuir-Blodgett (LB) films of fatty acids [1-3]. Investigations in the field of chemical modification of multimolecular LB layers are of great importance for the design of organized molecular assemblies as new nonclassical objects in the physics of low-dimensional systems as well as functional molecular electronics and sensor technology [4]. Formation of lead, zinc, and cadmium sulfides as nanosized clusters by reactions of the corresponding metal behenate films with gaseous hydrogen sulfide was established in [5], where sulfidizing of behenate films was studied at different temperatures and pressures of hydrogen sulfide. In this work we study the structure of the sulfides. Formation of nanoclusters was established, and their size and concentration in the film were determined. Experimental procedure. Cadmium and lead behenate fdms were prepared by the Langmuir-Blodgett procedure. To create monolayers on the surface of a liquid we used hexane solutions of behenic acid and cadmium chloride and lead acetate solutions as a subphase with a concentration of 3-5-10 -4 M, pH 7.0. The monolayers were transferred at a surface pressure of 30-35 mN/m and temperature 22-23~ Conditions of film sulfidizing: H2S pressure 50-100 Torr, temperature 20-5C the holes were subsequently covered with a LB film. These were just the regions investigated by HREM. To obtain an electron diffraction pattern in the reflection mode, the films were applied to polished silicon single crystal plates. Cadmium and lead behenate films of 20 to 30 monolayers (corresponding to a film thickness from 60 to 90 nm) were studied prior to and after sulfidizing. Completeness of sulfidizing was monitored by IR spectra. Experimental results. According to electron diffractometry, cadmium behenate films are characterized by a distinct plate-like texture (Fig. 1). The lattice is hexagonal and has a c axis that is close, on the average, to the normal to the support. Scanning the film showed a 10 ~ change in the inclination of the c axis. The parameters of the hexagonal lattice of the crystal as determined from electron diffractograms are a = 4.8 ~ and c = n 7.5 ~, where n is an integer. Recording by the skewed texture method revealed periodic intervals of 2.2-2.5 A along the c axis, which may be due to periodicity of the arrangement of carbon atoms in aliphatic chains. The crystal structure of lead behenate is analogous

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.

Study of the hydrodeoxygenation of carbonyl, car☐ylic and guaiacyl groups over sulfided CoMo/γ-Al 2O 3 and NiMo/γ-Al 2O 3 catalyst : II. Influence of water, ammonia and hydrogen sulfide

The hydrotreatment of various oxygenated groups (ketonic, car☐ylic, methoxyphenol) present in bio-oils in the presence of CoMo and NiMo catalysts was studied in a batch reactor using a mixture of model compounds mimicking the real feed. The influence of potential poisons or inhibitors of the reactions ( water, ammonia and hydrogen sulfide) was determined. High quantities of water had only a very slight inhibiting effect on the reactions. Ammonia strongly inhibited the conversion of car☐ylic esters and the removal of the methoxy group of guaiacol, but, surprisingly, the hydrogenation of the ketonic group was not affected. Hydrogen sulfide depressed the activity of the NiMo catalyst for the conversion of the ketonic group but not that of the CoMo catalyst. It had an enhancing effect on the conversion of the car☐ylic ester group and no effect on the removal of the methoxy group of guaiacol. The evolution of activities and selectivities as a function of the concentration of potential inhibitors provided an indication of the catalytic sites responsible for the various reactions. The absence of the influence of ammonia on the hydrogenation of the ketonic group was interpreted as resulting from the participation of nucleophilic sites and hydridic species in the reaction mechanism. Car☐ylic esters seem to react on electrophilic sites. Brønsted acids were thought to be responsible for decar☐ylation, while uncoordinated metal atoms and sulfhydryl groups could be responsible for the hydrogenation of car☐ylic groups. On the other hand, the surface of the alumina support catalyzes the hydrolysis of car☐ylic esters into acids. The demethylation of guaiacol occurs for a large part on the Lewis acid-base sites of the μ-alumina support. The use of hydrogen sulfide and ammonia shows a high potential for controlling the selectivity of reactions occurring in bio-oils hydrotreatment. The present results give hope that the deoxygenation of car☐ylic groups could be selectively performed through decar☐ylation thanks to cataltst selection and control of the hydrogen sulfide pressure. Ketonic groups and aldehyde groups could be selectively eliminated from complex feeds by applying a pressure of ammonia which would inhibit all reactions but hydrogenation.

N-Heptane hydrocracking over a sulfided NiMo/Y zeolite catalyst: reversible deactivation of the zeolite by sulfur - containing molecules

Hydrocracking of n-heptane was carried out over a sulfided NiMo/Y zeolite catalyst in the presence of ammonia and hydrogen sulfide. An increase in the hydrogen sulfide pressure decreased the activity of the catalyst and increased the isomerization/cracking ratio, which indicated a poisoning of the acid sites. This poisoning was accompanied by an increase in the formation of coke on the catalyst when the hydrogen sulfide pressure increased. The coke was composed mainly of sulfur-containing molecules, namely dimethyl polysulfides (tri-, tetra- and pentasulfides), and also pure sulfur: S 8. The deactivation of the catalyst was due to a blockage of the porosity of the zeolite by the sulfur polymers because of the low volatility of these compounds. The higher the hydrogen sulfide pressure the greater the amount of sulfur polymers, this phenomenon being totally reversible.

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.

Kinetics of desulfurization of hydrogen sulfide using metallic copper as a desulfurizer

AbstractThe kinetics of desulfurization of hydrogen sulfide, using metallic copper as desulfurizer, have been investigated over a range of temperatures and pressures of hydrogen sulfide. Our results indicate that there are two stages of reaction; activation energies for the first and second stages are 63 kJ/mol and 38 kJ/mol, respectively. Possible reaction mechanisms in which the initial rate is controlled by interface reaction and the later stage is controlled by diffusion through or in the Cu2S layer are consistent with the experimental 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.

Vapor-liquid equilibrium in selected aromatic binary systems: m-xylene-hydrogen sulfide and mesitylene-hydrogen sulfide

Huang, S.S.-S. and Robinson, D.B., 1984. Vapor—liquid equilibrium in selected aromatic binary systems: m-xylene—hydrogen sulfide and mesitylene—hydrogen sulfide. Fluid Phase Equilibria, 17: 373–382. Vapor and liquid equilibrium phase compositions have been determined for the m-xylene-hydrogen sulfide and mesitylene—hydrogen sulfide binary systems at temperatures of 310.9, 352.6, 394.3 and 477.6 K and at several pressures from the vapor pressure of the less volatile component to the vapor pressure of hydrogen sulfide or to the critical pressure for the system, whichever was higher. The data have been used to calculate equilibrium ratios for each of the components in the binary systems. The results of Eakin and DeVaney (1974) for the mesitylene—hydrogen sulfide system at 310.9 and 477.6 K are also included for comparison. The data presented are useful in evaluating the properties of condensate reservoir fluids containing hydrogen sulfide and aromatic compounds.

Influence of high partial pressures of hydrogen sulfide and carbon dioxide on the corrosion-mechanical properties of steels

Influence of high partial pressures of hydrogen sulfide and carbon dioxide on the corrosion-mechanical properties of steels

On the derivation and application of solution thermodynamics for reactive components: Application to an acid-gas system

Copeman, T.W. and Stein, F.P., 1983. ON the derivation and application of solution thermodynamics for reactive components: application to an acid-gas system. Fluid Phase Equilibria, 11: 49–64. Application of chemical theory has been made to the vapor—liquid equilibria of carbon dioxide and hydrogen sulfide in 5N aqueous monoethanolamine. Apparent unsymmetrical activity coefficients and partial pressures of hydrogen sulfide were calculated by means of a reliable, efficient algorithm which solves the equations on the true-species plane and projects the results back onto the apparent-component plane. The correlative possibilities of the procedure are illustrated by the development of a correlation for the apparent unsymmetrical activity coefficient of carbon dioxide in 5N aqueous monoethanolamine solution.

硫化物溶液中における低合金鋼の水素吸蔵現象

SCM3 steel (TS: 123kg/mm2) was immersed in the acetic buffer solution saturated with hydrogen sulfide gas of different partial pressure, and its hydrogen content was measured with a modified electrochemical technique.The hydrogen content was found to increase with partial pressure of hydrogen sulfide and to reach to 10ppm, which is about 140 fold compared with that in the absence of hydrogen sulfide. Also the mechanism of hydrogen evolution reaction was presumed from the usual polarization curve and the relationship between hydrogen content and electrode potential to be Volmer-Horiuti reactions in which the latter was the rate-determing. Hydrogen sulfide caused a significant shift of corrosion potential to less nobel, which means a sharp increase in hydrogen content.

The equilibrium phase properties of selected naphthenic binary systems: Carbon dioxide-methylcyclohexane, hydrogen sulfide-methylcyclohexane

Abstract Vapor and liquid equilibrium phase compositions have been determined at temperatures ranging from 310 to 478 K for two binary systems. Measurements were made at 311.0, 338.9, 394.0, and 477.2 K for the carbon dioxide—methylcyclohexane system and at 310.9, 352.6, 394.3 and 477.6 K for the hydrogen sulfide—methylcyclohexane system. At each temperature, pressures ranged from the vapor pressure of methylcyclohexane to the vapor pressure of hydrogen sulfide, or to a pressure near the critical for the system, whichever was higher. The data were used to calculate equilibrium ratios for each component in the binary system.

The equilibrium phase properties of the ethane-hydrogen sulfide system at subambient temperatures

Vapor and liquid equilibrium phase compositions were determined for the ethane-hydrogen sulfide system at 50.0, -0.1, -49.4, and -99.8 O F over the complete concentration range at pressures between the vapor pressure of hydrogen sulfide and the pressure of the minimum boiling azeotrope. The equilibrium ratios were calculated for each component In the blnary system. An equal area Integral test showed good thermodynamic consistency of the data. The capability of the PengRobinson equation of state for predicting the behavior of this system is Illustrated.

THE EQUILIBRIUM PHASE PROPERTIES OF THE i-BUTANE-HYDROGEN SULFIDE SYSTEM

Vapor and liquid equilibrium phase compositions and refractive indices were determined for the isobutane-hydrogen sulfide binary system at 40.1°, 100.0°, 160.2°, and 220.0°F from the vapor pressure of isobutane to the vapor pressure of hydrogen sulfide or to pressures in the critical region for the system. The measured phase compositions and refractive indices were used to calculate the equilibrium phase molal volumes using the Lorentz-Lorenz refractivity relationship. The saturated liquid phase exhibited a minimum in its refractive index at the three lower temperatures.