Solubility Of Hydrogen Sulfide Research Articles

Applications of Molecular Simulation in Oil and Gas Production and Processing

Molecular simulation is an emerging technique which consists in performing a detailed simulation of microscopic systems involving typically a few hundreds of molecules. On the basis of these simulations, appropriate statistical averages are performed to derive fluid properties that can be compared with experimental measurements. The purpose of the article is first to provide the reader with basic notions of molecular simulation. Then, application examples are given in several fields of the oil and gas industry. In reservoir engineering, the examples relate to the properties of poorly known hydrocarbons, the thermal properties of natural gases, and the phase equilibria and volumetric properties of acid gas - hydrocarbon mixtures. The application to gas production and processing is illustrated by the phase equilibria involving methanol (a common solvent or hydrate inhibitor) and the solubility at high pressure of gases in polymer materials. In hydrocarbon processing, the solubility of hydrogen sulfide in hydrocarbons at high temperature is discussed. For each type of problem, molecular simulation has provided useful predictions together with a better understanding of the relation between properties and chemical structure. It provides an intermediate way between experiments and classical thermodynamic models. Cheaper and more rapid than new measurements, it nonetheless allows an improved determination of the parameters of routine models.

Solubility of hydrogen sulfide in organic solvents

The solubilities of hydrogen sulfide expressed in mole fractions may be related, through multiparameter equations, to parameters that account for the specific and nonspecific solvation ability of the solvent and for the cohesion energy. The key factors are the self-association of the solvent, which reduces the solubility, and the complexing ability with hydrogen sulfide, which increases the solubility.

Gas solubility of H 2S in aqueous solutions of N-methyldiethanolamine and diethanolamine with 2-amino-2-methyl-1-propanol at 313, 343, and 393 K in the range 2.5–1036 kPa

The gas solubility of hydrogen sulfide in aqueous solutions of 32.5 wt.% N-methyldiethanolamine (MDEA) and 12.5 wt.% diethanolamine with 4, 6, and 10 wt.% 2-amino-2-methyl-1-propanol, at 313.15, 343.15, and 393.15 K, has been measured, using a volumetric method for the analysis of the liquid phase, over a range of pressure from 2.5 to 1036 kPa. The experimental results of the gas solubility are given as the partial pressure of H 2S against its mole ratio α (mol H 2S/mol total alkanolamine) and mole fraction of H 2S at each temperature studied. Enthalpies of solution of H 2S have been derived from the pressure-temperature concentration data. Experimental solubility data obtained in our laboratory for H 2S and CO 2 are compared, and it is possible to establish that the aqueous solutions of MDEA, DEA, and AMP studied in this work are highly selective towards H 2S under the same conditions of pressure and temperature.

Solubility of hydrogen sulfide in aqueous solutions of Fe(II) complexes of trans-1,2-cyclohexanediaminetetraacetic acid

Hydrogen sulfide is part of a well-known environmental problem afflicting pulp mills exploiting the Kraft mill sulfate-pulp process. Among the total reduced sulfurs (TRS) quartet (H 2S, CH 3SH, CH 3SCH 3, CH 3S 2CH 3), hydrogen sulfide is the most abundant component in the effluents. Utilization of Fe(III) chelate complex of trans-1,2-cyclohexanediaminetetraacetic acid (CDTA) for the oxidation of hydrogen sulfide is beneficial from the standpoint of iron-sequestration and protection against precipitation in the alkaline environments characteristic of the Kraft mill streams. The physical solubility of H 2S in CDTA-Fe(III) complexes, which is key for designing scrubbing-absorption, cannot be measured directly because of oxidation of the sulfur-bearing gaseous species with the ferric chelate. Therefore, the physical solubility of hydrogen sulfide in aqueous solutions in which H 2S does not react (Fe(II) complexes of CDTA) was studied at temperatures from 293 to 323 K and sub-atmospheric pressures. New experimental results over iron-free CDTA and CDTA-Fe(II) chelate concentrations ranging from 38 to 280 mol m −3 are reported. The Henry’s law constants and thermodynamic solution properties of H 2S in these solutions were correlated as a function of temperature and chelate concentration.

Experimental determination of hydrogen sulfide solubility data in aqueous alkanolamine solutions

A computer-operated static apparatus for the measurement of gas solubility data by the synthetic method was used for the experimental determination of hydrogen sulfide solubility data in aqueous N-methyldiethanolamine (MDEA), diethanolamine (DEA) solutions and aqueous solution of a mixture of MDEA/DEA. For these systems, measurements at 313 and 373 K and pressures up to about 1.3 MPa were performed. The experimental data from this work are presented in comparison to literature data. For the aqueous MDEA solution at 313 K, the solubility of H 2S was compared to the solubility of CO 2.

Gas Separation Method Using Tetra-n-butyl Ammonium Bromide Semi-Clathrate Hydrate

We used tetra-n-butyl ammonium bromide semi-clathrate hydrate, hereafter TBAB hydrate, as a tool for separating gases from binary mixed gas systems of methane+ethane, methane+propane, methane+hydrogen sulfide, methane+nitrogen, and carbon dioxide+hydrogen sulfide by growing the hydrate from 10 wt% TBAB aqueous solutions in a pressure vessel. TBAB hydrate has empty dodecahedral cages in the pure system. We found that small molecules such as methane, nitrogen, and hydrogen sulfide were selectively encaged during TBAB hydrate formation, probably because the dodecahedral cages are too small to incorporate large molecules such as ethane and propane. Furthermore, hydrogen sulfide was more readily encaged compared to the other small molecules; we argue that this was due to the very high solubility of hydrogen sulfide in water. We propose that gases with small molecular size and high solubility in water can be effectively separated using TBAB semi-clathrate hydrate.

Bifunctional Redox Scrubbing of Hydrogen Sulphide in Ferric Chelate Solutions - Reaction-Transport Model for Randomly Packed-Bed Scrubbers for Pulp and Paper Effluents

In recent years gas desulfurization processes based on iron chelate chemistry have received increasing attention from both industrial and academic research groups. Utilization of ferric chelates is beneficial because hydrogen sulfide solubility is higher in these solutions. This paper discusses from a multiphase reactor engineering perspective, the design of a randomly countercurrent packed bed column by setting an exhaustive modeling framework in which are integrated both the oxidation of hydrogen sulfide in reactive ferric chelate solutions of ethylenediaminetetraacetic acid and the regeneration of ferrous chelates resulting from oxidation of hydrogen sulfide. A one-dimensional model based on the volume-average species balance equations in the gas and liquid phases coupled with the diffusion-reaction equations for the reacting species in the liquid film was developed for the description of the space evolution of the species concentration in this important class of environmental reactions. The discretization of the diffusion-reaction equations in the film and the species balance equations in the gas and liquid phases was carried out by the method of orthogonal collocation and Newton-Raphson method was employed to solve the resulting non-linear system equations.

Solubility of H 2S in (H 2O + piperazine) and in (H 2O + MDEA + piperazine)

New experimental results for the solubility of hydrogen sulfide in aqueous solutions of piperazine are presented for piperazine molalities up to 4 mol/kg of water, temperatures between 313 and 393 K, and pressures up to about 9 MPa. Furthermore, the solubility of hydrogen sulfide was measured in about 2 m MDEA + 2 m piperazine aqueous solutions at 353 K up to about 6 MPa. Considering the new experimental data, a thermodynamic model for describing phase equilibria for the system H 2S–methyldiethanolamine–water has been extended allowing for the presence of piperazine.

Solubility of Hydrogen Sulfide and Carbon Dioxide in a Solution of Methyldiethanolamine Mixed with Ethylene Glycol

The equilibrium solubility of H2S, CO2, and their mixed gas in a solution of N-methyldiethanolamine (MDEA) mixed with ethylene glycol (EG) has been measured at temperatures from 25 to 90 °C, partia...

Solubility of H2S in H2O + N-Methyldiethanolamine + (H2SO4 or Na2SO4)

The solubility of hydrogen sulfide in aqueous solutions of N-methyldiethanolamine (MDEA) and MDEA sulfate (2 and 1 m, respectively) and in aqueous solutions of MDEA and sodium sulfate (2 and 1 m, respectively) was measured at temperatures from 313 to 393 K and total pressures up to about 3.9 MPa. The experimental results are used to extend and test a model for the thermodynamic equilibrium encountered in the solubility of hydrogen sulfide in such aqueous solutions.

Solubility of H2S and CO2 in N‐octyl‐2‐pyrrolidone and of H2S in methanol and benzene

AbstractThe solubility of hydrogen sulfide and carbon dioxide in N‐octyl‐2‐pyrrolidone (NOP) was measured up to 1.4 MPa at 303 and 324 K using the static synthetic method. Experimental results were compared to those of the predictive Soave–Redlich–Kwong (PSRK) model, wherein the group interaction parameters for the NMP‐group (N‐methyl‐2‐pyrrolidone) were applied to the NOP systems. The reliability of the apparatus used and the applied data treatment were checked by comparing new experimental data for the system hydrogen sulfide+benzene at 304 and 324 K and pressures up to 1.2 MPa, and for the system hydrogen sulfide+methanol at 298 K and up to 0.4 MPa, with published data measured with the analytical method.

Solubility of CO2 in H2O+N‐methyldiethanolamine +(H2SO4 or Na2SO4)

AbstractThe solubility of carbon dioxide in aqueous solutions of methyldiethanolamine (MDEA) sulfate (1 m), in aqueous solutions of MDEA and MDEA sulfate (2 m and 1 m, respectively), and in aqueous solutions of MDEA and sodium sulfate (2 m and 1 m, respectively) was measured at 313 K to 413 K and total pressures up to 10.6 MPa. The experimental results were used to extend and test a model for the thermodynamic equilibrium encountered in the solubility of carbon dioxide in such aqueous solutions.

Physical Solubility of Hydrogen Sulfide in Aqueous Solutions of 2-(tert-Butylamino)ethanol

The physical solubility of hydrogen sulfide in aqueous solutions of 2-(tert-butylamino)ethanol neutralized with hydrochloric acid was measured in this work. Measurements were made over the temperature range 25 °C to 40 °C and the amine concentration range 0 to 50 mass %. The solubility data exhibit a minimum in the solubility with amine concentration. The data were correlated using the van-Krevelen−Hoftijzer method for the “salting-out” effect up to the minimum solubility and by a new empirical method over the entire range of amine concentration.

Solubility of H 2S and CO 2 in diethylene glycol at elevated pressures

The solubility of hydrogen sulfide (H 2S) and carbon dioxide (CO 2) in diethylene glycol (DEG) has been determined at temperatures in the range 298–398 K at pressures up to 7.5 MPa (for H 2S) or 20 MPa (for CO 2). The experimental results were correlated by the Peng–Robinson equation of state, and interaction parameters have been obtained for these systems. The parameters in the Krichevsky–Ilinskaya equation were calculated from these interaction parameters. The vapor-phase compositions predicted by the equation of state have been compared with published data.

Solubility of Hydrogen Sulfide in Aqueous Solutions of the Single Salts Sodium Sulfate, Ammonium Sulfate, Sodium Chloride, and Ammonium Chloride at Temperatures from 313 to 393 K and Total Pressures up to 10 MPa

New experimental results for the solubility of hydrogen sulfide in aqueous solutions of the single salts sodium sulfate, ammonium sulfate, sodium chloride, and ammonium chloride at temperatures from 313 to 393 K and total pressures up to 10 MPa are reported. As in the salt-free system, a secondhydrogen sulfide-richliquid phase is observed at high hydrogen sulfide concentrations. A model to describe the phase equilibrium is presented. Calculations are compared to the new experimental data.

Physical solubility of hydrogen sulfide in several aqueous solvents

AbstractThe solubility of hydrogen sulfide in several aqueous solutions was measured over the temperature range 25°C to 60°C. The solvents investigated in this work include 0 to 50% aqueous solutions of polyethylene glycol, ethylene glycol, methyldiethanolamine and diethanolamine. The amine solutions used in this work were neutralized by the addition of hydrochloric acid in order to suppress the hydrogen sulfide reaction (H2S → H+ + HS−) so that only the physical solubility of hydrogen sulfide would be measured. The solubility data determined in this work are expressed in terms of Henry's law. The Henry's law constants found in this work were correlated well by a particularly simple empirical formula based on the molecular weight of the solvent.

Solubility of hydrogen sulfide in aqueous solutions of single strong electrolytes sodium nitrate, ammonium nitrate, and sodium hydroxide at temperatures from 313 to 393 K and total pressures up to 10 MPa

New experimental results for the solubility of hydrogen sulfide in aqueous solutions of the single strong electrolytes sodium nitrate, ammonium nitrate, and sodium hydroxide at temperatures from 313 to 393 K and total pressures up to 10 MPa are reported. As in the strong electrolyte-free system, a second — hydrogen sulfide-rich — liquid phase is observed at high hydrogen sulfide concentrations. A thermodynamic model for describing the phase equilibrium is presented. Calculations are compared with the new experimental data.

Solubility of hydrogen sulfide in pure water and in NaCl solutions, from 20 to 320°C and at saturation pressures

The solubility of hydrogen sulfide in pure water and in NaCl solutions has been studied experimentally from 20 to 320°C and at saturation pressures. Hydrogen sulfide solutions in equilibrium with their vapor phase were contained in a pressurized titanium bellows of known total volume. The bellows transmitted inside-vapor pressures via a thermally stable oil (pressure medium) to a high-precision pressure sensor. Temperatures were measured by a sheathed thermocouple immersed into the oil surrounding the bellows. Values for the Henry constants were derived from measurements of equilibrium vapor pressure, volume, temperature, and bulk composition. The Henry constants agree well with previously published data up to about 200°C, but then deviate towards lower values (higher solubilities) at higher temperatures. Henry constants from 20 to 320°C and at saturation pressures may be obtained from the correlation log k H ( T, P sat,1 ) = +0.6342702616 e + 3 + 0.2709284796 e + 0 · T − 0.1 113202904 e − 3 · T 2 − 0.1671907660 e + 5/ T −0.2619219571 e + 3 · log T, where k h is in units of bar/molality and T in Kelvin. The experimental Henry constants have been fitted to a scaled particle theory model and have been tested by a recently proposed linearization procedure. The salting-out effect of NaCl on H 2S solubility is nearly independent of temperature up to about 250°C, but then increases sharply as temperatures approach the critical point of water. Skeleton tables to 365°C and for ionic strengths μ = 0, 1, 2, 3 have been prepared.

Gas solubility of hydrogen sulfide and carbon dioxide in mixtures of sulfolane with diethanolamine at different temperatures

Murrieta-Guevara, F., Rebolledo-Libreros, E. and Trejo, A., 1994. Gas solubility of hydrogen sulfide and carbon dioxide in mixtures of sulfolane with diethanolamine at different temperatures. Fluid Phase Equilibria, 95: 163-174.

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.